Episode 25: Doctor Dan does an expose on how his Physics knowledge has stayed strong for so long! Listen to the podcast to learn who she is…

MCAT Physics

Vectors

Scalar quantities, such as temperature, have magnitude only and are specified by a number with a unit, 67 degrees Celsius and obey the rules of ordinary algebra.  Vectors, such as displacement, have both magnitude and direction, six meters west and obey the special rules of vector algebra.

X and Y Coordinates

Two vectors A and B may be added geometrically by drawing them to a common scale and placing them head to tail.  The vector connecting the tail of A to the head of B is the sum vector.  To subtract B from A, reverse the direction of B and then add to A.  The component A_X and A_Y of any vector A are the perpendicular projections of A on the coordinate axes.

Pythagoras’ theorem

Analytically, the components are given by A_X=A (cos theta) and A_Y=A (sine theta).  Given the component, we can reconstruct the vector from:  A is given by the square root of the quantity, A_X² + A_Y², which is a derivation of the Pythagoras’ theorem.

Kinematics

The motion of a body is described by giving its position or displacement, its velocity and its acceleration.  The average speed is defined as the distance traveled divided by the elapsed time.  The average velocity is the displacement vector divided by the elapsed time.

Displacement

Displacement is the vector representing the position of an object relative to its position at some chosen earlier time, or its point of origin.  Whereas speed is a scalar quantity, velocity is a vector.  The instantaneous velocity whose magnitude is the same as the instantaneous speed is the average velocity taken over an indefinitely short period of time.

Acceleration

Velocity as well other qualities describing motion are always measured with respect to some frame of reference.  Acceleration is the rate of change of velocity.  The change of velocity divided by the elapsed time, it is a vector.  If an object moves in a straight line with constant acceleration, the velocity, V, and the acceleration, A, are related to the initial velocity V₀ and the displacement, D, and the time, T, by the equations-V=V₀ + AT; D, the displacement, equals V₀T + ½AT²; V²=V₀² + 2AD.  The mean velocity equals V + V₀/2.  Objects allow to fall freely without air resistance all fall with the same constant acceleration, G=9.8 meters/second².

Motion and force.

Newton’s 3 Laws

Number 1

Newton’s three laws of motion are the basic laws explaining motion.  Newton’s first law states that if the net force on an object is zero, the object at rest remains at rest and an object in motion remains in motion in a straight line with constant velocity.  The tendency of a body to resist a change in motion is called inertia.  Mass is a measure of inertia.  Weight refers to the force of gravity on an object.

Number 2

Newton’s second law states that the acceleration of a body is directly proportional to the net force acting on it and inversely proportional to its mass.  F=ma, where F is the force, m is the mass, and A, the acceleration.  Force, which is a vector, is a push or a pull.  More precisely, Newton’s second law can be used as a definition of force as that action which is capable of accelerating an object.  Net force refers to the vector sum of all forces acting on a body. The force of gravity acting on a body is the product of its mass times the acceleration of gravity.

Number 3

Newton’s third law states that when every one body exerts a force on a second body, the second exerts an equal force on the first in the opposite direction.  A consistent set of units must always be used when making calculations.  SI unit s are the standard ones used for scientific work and these include the meter, kilogram and second.

Friction

When two bodies are in contact or slide over one another, the force of friction each exerts on the other can be written force of friction equals mu N, where N is the normal force, the force each body exerts on the other perpendicular to the surface in contact.  Mu is the coefficient of kinetic friction if the bodies are moving relative to each other.  If they are not moving, the above equation gives the maximum friction force where mu is the coefficient of static friction.

Projectile motion

That of an object moving through the air can be analyzed as two separate motions in the horizontal and vertical directions.  If air resistance can be ignored, the horizontal motion is at constant velocity where the vertical motion is uniformly accelerated and is the same as for the body falling vertically under the action of gravity.

Circular motion and gravitation

Angular quantities are defined in analogy with linear quantities.  Angles can be measured in degrees, revolutions or radians, where two pi radians is equal to one revolution, which is equal to 360 degrees.  A particle moving with constant speed, V, in a circle of radius, R, has a linear centripetal, which means towards the center acceleration.  That acceleration is given by V²/R.  Because the velocity vector is continually changing in direction, that’s why there is an acceleration.  A force acting towards the center is thus needed to keep a particle revolving in a circle.  If the particle is revolving in a circle with non-uniform speed, it will have both centripetal and tangential linear acceleration.

Gravity

Newton’s law of universal gravitation states that every body in the universe attracts every other body with a force proportional to the product of their two masses and inversely proportional to the square of the distance between them.  It is this force of gravity that keeps the moon in its orbit around the Earth and the planets in their orbits around the sun.  The dynamics of rotation is analogous to the dynamic of linear motion.  Force can be replaced by torque which is defined as the product of force times the perpendicular distance from the pivot point.

Inertia

Mass is replaced by the moment of inertia which depends not only on the mass of the body, but also on how the mass is distributed about the axis of rotation.

Angular Acceleration

And linear acceleration is replaced by angular acceleration.  So, instead of seeing F=ma as we previously saw, now we have the rotational equivalent of Newton’s second law, which is tau, the torque force, equals I, the moment inertia times alpha, the angular acceleration.

Center of Gravity

The center of gravity of a body is that point at which the force of gravity can be considered to act for purposes of determining the motion of the body as a whole.  The complete motion of a body can be described as the translational motion of its center of gravity, plus the rotation about its center of gravity.

Equilibrium

We will now discuss bodies in equilibrium.  A body at rest or one in uniform motion at constant velocity is said to be in equilibrium.  The determination of the forces within a structure at rest is the field called statics.  The two necessary conditions for a body to be in equilibrium are:  one, the vector sum of all the forces on it must be zero and, two, the sum of all the torques calculated about any arbitrary point as axis must also be zero.  It’s important when doing statics problems to apply the equilibrium conditions to only one body at a time.

A body in static equilibrium is said to be in stable, unstable or neutral equilibrium, depending on whether a slight displacement leads to a return to the original position, that would be stable equilibrium, or further movement, which would be unstable, or a rest in the new position, which would be neutral equilibrium.  An object in stable equilibrium is also said to be in balance.

Elasticity

Hooke’s law applies to many elastic solids, and states that the change in length of an object is proportional to the applied force.  If the force is too great, the object will exceed its elastic limit, which means it will no longer return to its original shape when the distorting force is removed.  If the force is even greater, the ultimate strength of the material can be exceeded and the object fractures.

Stress

The force per unit area acting on a body is called the stress.  And the resulting fractional change in length is called the strain.  The stress on a body is present within the body and can be of three types-compression, tension and shear.  The ratio of stress to strain is called the elastic modulus of the material.  Young modulus applies for compression and tension and the shear modulus for shear.

Both moduli apply to an object whose volume changes as a result of pressure on all sides.  All three moduli are constants for a given material when distorted within its elastic region.

The subject of statics is especially useful for calculating forces within muscles and bones and in structures such as buildings and bridges.

Momentum and energy

The momentum, P, of a body is defined as its mass times its velocity where P=MV.  In terms of momentum, Newton’s second law can be written, F, the force equals dP over dT, which is the rate of change of a momentum equals the net applied force.

Momentum is a conserved quantity.  The law of conservation of a momentum states that the total momentum of an isolated system of objects remains constant.  An isolated system is one on which the net external force is zero.

Work

Work is done on an object by a force when the force moves the object through a distance, D.  If the direction of the force makes an angle, theta, with the direction of motion, the work done by this force is given by W=FD (cos theta).

Energy

Energy is defined as the ability to do work.  Both work and energy are measured in Joules, where one Joule equals one Newton meter.  Kinetic energy is energy of motion.  A body of mass, m, and speed, V, has translational kinetic energy equal to ½ MV².

An object can have potential energy by virtue of its position or shape.  Examples are gravitational potential energy, which is equal to mgh, where h is the height of the object of mass, m, above an arbitrary reference point.  An object can also have elastic potential energy, such as a compressed spring.  An object can also have chemical, electrical, or nuclear energy.

The change of potential energy of an object when it changes position is defined as the work needed to take it from one position to the other.  The work energy theorem states that the net work done on a body by the net force equals the change in kinetic energy of that body.

The law of conservation of energy states that energy can be transformed from one type to another, but the total energy remains constant.  It is valid even when friction is present since the heat generated by friction can be considered a form of energy.  Momentum is conserved in any collision between objects.  Energy is conserved, too, but kinetic energy only in so-called elastic collisions in which other forms of energy do not change.

Power

Power is defined as the rate at which work is done or the rate in which energy is transformed.  The SI unit of power is the watt, where 1 watt equals one Joule per second.

Fluids

Now, let us look at fluids.  The three common phases of matter are solid, liquid and gas.  Liquids and gases are collectively called fluids.  Meaning they have the ability to flow.  The density of a material is defined as its mass per unit volume.  Specific gravity is the ratio of the density of the material to the density of water.  Pressure is defined as force per unit area.  The pressure at a depth, h, in a liquid is given by rho gh, where rho is the density of the liquid and g is the acceleration due to gravity.

In addition, if an external pressure is applied to a confined fluid, this pressure is transmitted throughout the fluid.  This is known as Pascal’s principle.  Pressure is measured using manometer or other types of gauge.  A barometer is used to measure atmospheric pressure.  Standard atmospheric pressure, which is the average at sea level, is 1.01 x 10⁵ Newton per meter squared.

Archimedes Principle

Archimedes principle states that an object submerged wholly or partially in a fluid is bouoyed up by a force equal to the weight of fluid it displaces.  This principle is used in a method to determine specific gravity and explains why objects whose density is less than that of liquid will float in that liquid.

Fluid flow rate is the mass or volume of fluid that passes a given point per unit time.  The equation of continuity states that for an incompressible fluid flowing in an enclosed tube, the product of the velocity of flow and the cross-sectional area of the tube remains constant.  AV is a constant.

Bernoulli’s Equation

Bernoulli’s equation tells us that where the velocity of a fluid is high, the pressure in it is low.  And where the velocity is low, the pressure is high.  Bernoulli’s principle explains many common phenomena.  Fluid flow can be characterized either as streamline, sometimes called laminar in which the layers of fluid move smoothly and regularly along paths called streamlines, or it can be characterized as turbulent in which case the flow is not smooth and regular, but it’s characterized by irregularly shaped whirlpools.

Viscocity

Viscosity refers to friction within a fluid that prevents the fluid from flowing freely and is essentially a frictional force between different layers of fluid as they move pass one another.

Temperature and the kinetic theory.  The atomic theory of matter postulates that all matter is made up of tiny entities called atoms.  Some substances are made up of only one type atom, and these are called elements.  Atoms can combine to form molecules and substances made up of a single type of molecule are called compounds.  A substance made up of more than one type of molecule is called a mixture.

Atomic and molecular masses are specified on a scale that’s compared to Carbon 12.  The distinction between solid, liquid and gases can be attributed to the strength of the attractive forces between the atoms and molecules and depends on their average speed.

Temperature is a measure of how hot or cold a body is.  Thermometers are used to measure temperature on the Celsius, Fahrenhiet and Kelvin scales.  Two standard points on each scale are the freezing point of water, which is zero degrees Celsius, 32 degrees Fahrenhiet, and 273 Kelvin, and the boiling point of water which is 100 degrees Celsius, 212 degrees Fahrenhiet, and 373 degrees Kelvin.  A change in temperature of one Kelvin equals a change of one Celsius degrees or 9/5 Fahrenhiet degrees.

The change of length, L, of a solid when its temperature changes by an amount, T, is directly proportional to the temperature change and to its original length, L_0. That is L is equal to alpha L₀ T, where alpha is the coefficient of linear expansion.

The change in volume of most solids, liquids and gases is proportional to the temperature change and to the original volume, V₀, where V is equal to beta V₀ T.  The coefficient of volume expansion, beta, is approximately equal to 3 times alpha for solids.  Water is unusual because unlike most materials whose volume increases with temperature, its volume actually decreases as the temperature increases from 0 degrees Celsius to 4 degrees Celsius.

Kinetic Theory of Gases

According to the kinetic theory of gases, which is based on the idea that a gas is made up molecules that are moving rapidly and at random, the average kinetic energy of the molecule is proportional to the Kelvin temperature.  At any moment, there exists a wide distribution of molecular speeds within a substance.

Heat

Thermal energy or internal energy refers to the total energy of all the molecules in a body.  Heat refers to the transfer of energy from one body to another because of a difference of temperature.  Heat is thus measured in energy units such as Joules.  Heat and thermal energy are also sometimes specified in calories or kilocalories where one calorie is equal to 4.18 Joules, and one calorie is the amount of heat needed to raise the temperature of one gram of water by 1 degree Celsius.

Heat Capacity

The specific heat capacity, C, of a substance is defined as the energy or heat required to change the temperature of unit mass of substance by 1 degree.  In the equation, Q=mc T, where Q is the heat absorbed or given off, T the temperature rise or decline, and m, the mass of the substance, that is Q=mc T.  When heat flows within an isolated system, the heat gained by one part of the system is equal to the heat lost by the other part of the system.

Calorimetry

This is the basis for calorimetry, which is the quantitative measurement of heat exchange.  An exchange of energy occurs without a change in temperature whenever substance changes phase.  This happens because the potential energy of the molecules changes as a result of the changes in the relative positions of the molecules.

Heat of Fusion

The heat of fusion is the heat required to melt one kilogram of a solid into the liquid phase.  It is also equal to the heat given off when the substance changes from liquid to solid.  The heat of vaporization is the energy required to change one kilogram of a substance from the liquid to the vapor phase.  It is also the energy given off when the substance changes from vapor to liquid.

Heat Transfer

Heat is transferred from one place or body to another in three different ways.  In conduction, energy is transferred from higher kinetic energy molecules to a lower kinetic energy neighboring molecules when they collide.  Convection is a transfer of energy by the mass movement of molecules over considerable distances.  Radiation, which does not require the presence of matter, is energy transfer by electromagnetic way, such as from the sun.

All bodies radiate energy in an amount that is proportional to their surface area and to the fourth power of their Kelvin temperature.  The energy radiated or absorbed also depends on the nature of the surface, dark and absorbing versus brightly reflecting, which is characterized by the emissivity.

The first and second laws of thermodynamics

The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system, Q minus the work, W, done by the system.  This is simply a restatement of the conservation of energy and it’s found to hold for all types of processes.

The second law of thermodynamics can be stated in several equivalent ways.  One, heat flows spontaneously from a hot object to a cold one but not the reverse.  Two, there can be no 100% efficient heat energy.  That is, one that can change a given amount of heat completely into work.  And, three, natural processes tend to move toward a state of greater disorder or greater entropy.  Entropy is a quantitative measure of the disorder of the system.  From statistical point of view, the most probable state of a system is that with the most entropy or disorder.

Vibrations and waves

A vibrating object undergoes simple harmonic motion if the restoring force is proportional to the displacement.  In other words, it obeys Hooke’s law.  The force constant, K, is the ratio of restoring force to the displacement.  The maximum displacement is called the amplitude.  The period, T, is the time required for one complete cycle back and forth and the frequency, F, is the number of cycles per second.  They are related by F=1/T, the period.  The period of vibration for a mass, m, on the end of a spring is given by the following relationship.  T=2 pi square root quantity m/K.

Harmonic Motion

Simple harmonic motion is sinusoidal, which means that the displacement as a function of time follows a sine or a cosine curve.  A simple pendulum of length, L, approximates simple harmonic motion if the amplitude is not too great.  Its period is given by, T=2 pi the square root of l/g, where g is the acceleration due to gravity.

Resonance

During a vibration, the energy continually alternates between kinetic and potential.  When friction is present, the motion is said to damped.  The displacement decreases in time and the energy is eventually all transformed to heat.  When an oscillating force is applied to a system capable of vibrating, the amplitude of vibration is very large if the frequency of the applied force equals or nearly equals the natural frequency of vibration of the object.  This is called resonance.

Cancers and Associated Diseases - Part II

Xeroderma pigmentosa – sun exposed areas, auto recessive, can cause all skin cancers (BCC, SCC, and melanomas), and the defect is in DNA repair enzymes. Other DNA repair defects are associated with BRCA1 and BRCA2, p53, they splice out the defects, this group is called the chromosomal instability syndromes – Wiskott Aldrich, Blooms, Ataxia Telangiectasias, and Fanconi’s, all have probs with DNA repair.

Basic rule of thumb for BCC and SCC:

• Upper lip and up is basal cell carcinoma;
• lower lip and down is squamous cell

(therefore, lesion on lower lip = sq cell; lesion on upper lip = basal cell)

Example: inside nose is BCC, b/c above the upper lip

Example: keloid – sq cell carcinomas and 3rd degree burns and sq cell carcinoma developing in areas of drainage from the sinus and ulcer that doesn’t heal from antibiotics. So, wherever there is constant irritation, and division of cells related to irritation, there is an increase susceptibility to cancer. This does not hold true for scar cancer tissue related cancers of the lungs or adenocarcinoma (just applies to things on the skin – ie burns and draining of sinus tracts). Only bacteria assoc with cancer? H. pylori – adenocarcinoma and low grade malignant lymphomas.

XII. Grade vs Stage

A. Grade = what does it look like? The term well differentiated means that the tumor is making something like keratin or glands, and if it’s identifiable it’s called low grade. When the cells are anaplastic, poorly differentiated under the microscope, and if you cannot tell what it is, then it’s called high grade.

Example: sq cell carcinoma can see keratin pearls; can ID it, so it’s a low grade cancer.

Example: see gland like spaces, can ID so its low grade

B. Stage = (TNM) MC staging system; goes from least imp to most imp (TNM)

Example: breast cancer with axillary node involvement; therefore, the N=1, but the “M” is worse, b/c it indicates that cancer has spread to other organs like bone, etc. Just b/c it goes to lymph nodes doesn’t mean it is the most imp prognostic factor.

T=size of tumor; if tumor is over 2 sonometers, it has a chance of mets

N=nodes (next most imp for prognosis)

M=mets outside of nodes (most imp prognostic factor)

Stage is more important than grade for prognosis; and within staging, M is the most imp factor for prognosis.

Example: pt with prostate cancer, which of following has it the worst? The answer choices were cancer limited to prostate, it went into seminal vesicles, it involved the wall of bladder, went to lymph nodes, or bone? Answer = bone (bone represents the “M” of the TNM system – this is stage 4 by definition=mets)

Example: a slide of a colon cancer and a lymph node: what is most important – size of tumor or lymph node involvement? Lymph node. If it was also in the liver, what is most imp? Liver specimen is the most imp prognostic factor.

XIII. Host defenses – most important is Cytotoxic CD8 T cell

Others – NK cells, Ab’s, macrophages, type 2 HPY. In hospital, they look for altered MHC class I Ag’s in the cancer pt, b/c cancer wants to kill T cells; they do this by putting in perforins, which activate  caspasases, and this leads to apoptosis (the signal, from the perforins, activate the caspasases, which have proteases, which break down the nucleus and mitochondria, and cell dies, without any inflammatory infiltrate).

XIV. Other diseases seen in malignancy:

A. Cachexia – cause is TNF alpha; it is irreversible. Once you see a pt with disseminated cancer about to go into catabolic state, can give then total nutrition, but still won’t help. (Will not get muscle mass back, and this is due to TNF-alpha)

B. Many hematologic causes of anemia seen in malignancy

MC anemia in malignancy is Anemia of chronic disease (this is the overall most common)

Colon cancer: left side obstructs w/ right side bleeds; if you have RT side bleed in colon cancer, Fe def anemia is very common.

Mets to BM and replace BM. Or, use chemotherapy drugs that are cell cycle specific or cell cycle nonspecific – they wipe out the marrow. Can have autoimmune mechanism with certain malignant dz.

C. Associations with disseminated cancers:

1. Most pts with disseminated cancers are hypercoagulable, meaning that they have a tendency for forming clots. Classic Example: a pt with painless jaundice, left supraclavicular node (this is a distracter), had light color stools, lesions that jump from one part of body to next – trousseau’s sign: a superficial migratory thrombophlebitis due to carcinoma of the head of the pancreas). Pancreatic cancers can ALSO mets to left supraclavicular node (virchow’s node), and often describe trousseau’s sign, which is a vascular problem in the veins that jumps from one place to the next.

2. Another common thing seen is disseminated cancers is thrombocytosis – an elevated platelet count. Other causes of thrombocytosis: Fe def, splenectomy (ie see scar on abdomen), TB, anemias. If you  cannot find any obvious cause of thrombocytosis then the cause is cancer. 40% of disseminated cancers are thrombocytosis. Or a do a stool guaic for colon cancer.

D. MCC fever in malignancy = gram neg. infection. An E. coli if you have an indwelling catheter; Pseudomonas if you have a respirator, staph aureus can also be the cause from an indwelling catheter, but this is gram “+”. MCC death in cancer = infection.

XV. Paraneoplastic syndromes

These are signs and sometimes symptoms saying that you may have an underlying cancer present. Its important b/c when you recognize the signs and symptoms, then you can catch the cancer before it metastasize.

MC Paraneoplastic syndrome = hypercalcemia

2 mechanism for hypercalcemia in malignancy:

1) mets to bone, produce a chemical (IL-1, PGE2, both of which activate osteoclasts) that produces lytic lesions in bone, and you get hypercalcemia

2) renal adenocarcinoma or squamous carcinoma of mainstem bronchus that sits there and makes PTH-like peptide and causes hypercalcemia b/c it acts like PTH and breaks down bone. This is Paraneoplastic, but it’s not the most common one.

Example: 2 black lesions – both are markers for gastric adenocarcinoma; usually under the arm – called acanthosis nigricans, and other is called seborrheic keratosis (these are not neoplasms); however, when  these suddenly develop overnight, you get multiple outcroppings, and the outcroppings is a phenotypic marker for gastroadenocarcinoma; this is easy to remember b/c 2 black lesions are markers from gastroadenocarcinoma.

Example: clubbing – inflammation beneath on the bone called periostitis; inflamm of underlying bone causes proliferation of the soft tissue around it, which leads to clubbing (called hypertrophic osteoarthropathy). Clubbing is not always assoc with cancer; also assoc with bronchiectasis, IBS. But, if it’s a malignancy, it is due to primary lung dz.

Example: least common collagen vascular dz, but the most often assoc with a certain cancer. They have an elevation of serum CK; this is dermatomyositis; raccoon eyes, so you see inflammation of skin and muscle; high assoc with leukemias, lymphomas and lung cancer. patches of knuckles – Goltrin’s patches (seen in dermatomyositis).

Example: vegetations (sterile) on the mitral valve – assoc with mucous producing cancers such as colon cancer; this is called marantic endocarditis-aka nonbacterial thrombotic endocarditis; they are not infections and these marantic vegetations are assoc with mucous secreting colon cancers. Can they embolize? Yes. You will need history to separate from rheumatic fever, but history will relate more to colon cancer (ie polyarthritis).

Example: hyponatremia or Cushing’s – cancer in the lung = small cell carcinoma, which is secreting either ADH or ACTH; also, for small cell, they are aput tumors, S-100 Ag positive, neural crest origin, neural secretory granules.

Example: Hypercalcemia or secondary polycythemia: renal adenocarcinoma (can make PTH like peptide and/or EPO).

Example: Hypoglycemia or secondary polycythemia: Hepatocellular carcinoma (they can make EPO or insulin-like factor).

Example: Hypocalcemia or Cushing’s: auto dominant, and the rare tumor marker that can be converted to amyloid (calcitonin) – medullary carcinoma of the thyroid.

XVI. Tumor markers

1. 2 markers associated with Testicular cancer – alpha feto protein (AFP) (which is really the albumin of a fetus) and HCG.
2. AFP is a maker for–yolk sac tumor (endodermal sinus tumor). So the tumors in kids are yolk sac tumors (alpha feto protein). AFP is also assoc with Hepatocellular carcinoma, increased in neural tube defects (must be on folate while pregnant to prevent neural tube defects). In Down’s syndrome AFP is decreased. Marker for malignancy in bone, assoc with monoclonal spike: Bence Jones Proteins (light chain Ig), assoc with Multiple Myeloma.
3. Tumor marker for prostate cancer: PSA; not sp for cancer b/c it can be also increased in hyperplasia; it is sensitive but not specific. If you do a rectal exam, it is not increased. PSA is NOT an enzyme; it is an Ag and is within the actual cell. It will not increase with a rectal exam.
4. Breast cancer (surface derived) – 15, 3.
5. CEA–125: Ovarian cancer
6. CEA –Ag for colon cancer; and sometimes used for small cell, and breast ca. CEA can be a part of an immune complex, and will get CEA: anti-CEA immune complexes which deposit in the kidney, and lead to nephrotic syndrome – this is diffuse membranous glomerulonephritis = MC overall cause of nephrotic syndrome. Many of these are related to malignancy b/c CEA can be the Ag that is deposits in the glomeruli.
7. Woman with a trophoblastic mole, what would you get? Beta HCG

Most Common Causes (MCC) of Cancer:

• What is MC primary tumor of the brain in kids? Cerebellar cystic astrocytoma (B9). It’s not medulloblastoma. All astrocytomas are B9 (if asked what is the most common malignant primary tumor, and then the answer is medulloblastoma, which derives from cerebellum). MC actual tumor of the brain – cerebellar tumor derived from astrocytes;
• MC childhood cancer = ALL leukemia (other childhood tumors include CNS tumors, neuroblastomas (in the adrenal medulla), Burkitts, Ewing’s (tumor of bone with onion skinning), embryonal rhabdomyosarcoma.)
• Adults: incidence:
• Woman: breast, lung, colon
• Men: prostate, lung, and colon
• Killers: lung is #1 in both (followed by prostate/breast and colon)
• 2nd MC cancer and cancer killer in men and women combined = colon
• Therefore, from age 50 and on, you should get a rectal exam and a stool guaic. After 50, MCC cancer of “+” stool guaic is colon cancer.
• MC gyn cancer: endometrial (#2 is ovarian, and #3 is cervix)
• Cervix is least common b/c Pap smear. When you do a cervical pap, picking up cervical dysplasia, not cervical cancer (therefore the ‘incidence’ isn’t the highest).
• B/c cervical pap smears; the incidence of cervical cancer has gone down significantly b/c the detection of the precursor lesion, cervical dysplasia. So, b/c cervical Pap smear, incidence of cervical cancer has gone down dramatically (picking up the precursor lesion); with mammography, the incidence of breast cancer decreases, same with PSA.
• MC Gyn cancer killer: ovarian (#2 = cervical, #3 = endometrial); therefore to remember, the MC has the best prognosis – endometrial is MC and has the best prognosis. What is the only known existing tumor vaccine? HBV …why? MC infection transmitted by accidental needle stick in the hospital = Hepatitis B. B/c viral burden of Hepatitis B is greater than any infection, even more so than HIV. So, with the Hepatitis B vaccine, you won’t get three things (1) Hepatitis B, (2) Hepatitis D (requires Hep B), and (3) hepatocellular carcinoma (related to Hepatitis B related cirrhosis).

How do you eradicate hepatocellular carcinoma? Vaccination (ie in the Far East).

H.R. 3590

On March 23, 2010, President Obama signed H.R. 3590, the most sweeping health care legislation bill in our nation’s history.

What is in the health care bill?

Doctor Dan will be teaching the contents of H.R. 3590 and what to expect in a non-political way at the 3rd Annual Medical School LIFE Conference in Dallas, Texas on May 29-30, 2010.

Pre-Nursing Advice

Over the years, I’ve had a lot of questions about other medical careers besides becoming a physician.

Today’s interview with Dr. Naheeds Ali covers a few basic pieces of pre-nursing advice:

1. Study your career field in advance from people who are doing it

2. Don’t assume financial security, even in the nursing profession

3. In your career choices, stay within your educational background

Non-Clinical Careers For Physicians

Dr. Ali gave some good insight into what physicians consider when they leave clinical medicine.

Here are some of the things doctors consider when they leave clinical medicine:

1. How the economy will affect physician careers

2. Love of teaching

Now all of the MCAT science exams are available here: 

Download MCAT Podcasts

Dr. Brett Ferdinand has been teaching and authoring MCAT books and DVD’s for nearly 2 decades. Recently, he co-authored a book with Dr. Flowers, the father of MCAT Prep books (Silver Bullet MCAT).

Conservation of Mass

The Law of Conservation of Mass state that there are no detectable changes in mass in any chemical reaction.  This indicates that there are the same number of atoms of each types present after a chemical reaction as there were before the reaction.  A balanced equation shows equal numbers of each type of atom on each side of the equation and is, thereby, consistent with the Law of Conservation of Mass.

MCAT Equations (download complete list of MCAT equations)

Equations are balanced by placing coefficients in front of the chemical formulas for the substances involved in the reactions.  It is possible to predict the products of simple reactions by analogy to known reactions and by use of the periodic table.  Among the reactions, there are the followings:

One; combustion in oxygen in which an organic compound reacts with oxygen forming carbon dioxide, water and possibly other products depending on the composition of the compound.

Two; neutralization reaction in which an acid plus a base react to form water or another neutral compound and a salt.  There are precipitation reactions in which one of the products over reaction between two substances in solution is insoluble in the solution.  The coefficient in a balanced equation can be interpreted as either the relative number of formula units involved in the reaction or the relative number of moles.

Avagadro’s Number

A mole of any substance is Avogadro’s number, which is 6.02 x 10²³ of formula units of that substance.  The mass of a mole of atoms, molecules or ions is the formula weight expressed in grams.  For example, a single molecule of water, H₂O, weighs 18 amu, which are atomic mass units.  A mole of water weighs 18 grams.  The empirical formula, or simplest formula, of a substance expresses the composition in terms of the smallest possible set of whole number subscripts denoting the relative number of atoms.  The mole concept can be used to determine the empirical formula of a compound and calculate the quantities involved in chemical reactions.  In dealing with reactions between substances and solutions, it is convenient to employ the concept of solution concentration.

Molarity

Molarity is defined as the number of moles of solute per liter of solution.  Molarity serves as a conversion factor for interconverting solution volume and number of moles of solute.

Chemical equations and energy

We will look specifically at the energy and the first law of thermodynamics.  Energy can be measured in terms of the ability to accomplish work or transfer heat.  An object may possess potential energy because of its position relative to another object or because of its composition.  Thus, chemical energy is potential energy which can be released when the object undergoes a chemical change.  An object may possess kinetic energy because if it’s relative motion to another object.  The first law of thermodynamics also referred to as the law of conservation of energy states that in any change that occurs in nature, the total energy of the universe remains constant.

It is often convenient to consider one portion of nature called the system as separate from all the rest called the surroundings.  According to the first law of thermodynamics any energy gained by the system in a change must equal the energy lost from the surroundings.  Any process in which heat energy is lost to the surroundings is termed “exothermic”.  On the other hand, when heat energy is absorbed by the system from the surroundings, the process is termed “endothermic”.

Heat changes occurring at constant pressure are of special interest.  The heat gained or lost by the system in a process occurring at constant pressure is termed the enthalpy change, represented by the symbol delta H.  This quantity is negative for an exothermic process and positive for an endothermic process.

Enthalpy

Enthalpy is a state function, which means that the enthalpy of a system is determined by specifying its present condition and not by the details of how it came to be in that state.  If a particular overall change can be described as the sum of several individual changes then enthalpy change for the overall process is equal to the sum of the enthalpy changes associated with the individual steps.

Hess’ Law of Constant Heat Summation

This statement is known as Hess’s law of constant heat summation. In applying Hess’s law, it is useful to define the standard heat of formation of a substance, which is the heat change in the formation of a substance from the elements, all in the states in which they are most stable at the temperature of interest.  This is usually 25 degrees Celsius.

Using Hess’s law, the enthalpy change in any reaction can be described as the sum of the heat of formation of all the products, less the heat of formation of all reactants.  In solving problems dealing with enthalpy changes, it is important to keep the following points in mind.

First, the enthalpy change in a reaction, delta-H, is directly proportional to the amount of substance that reacts or is produced.  Secondly, delta-H for any reaction is equal in magnitude but opposite in sign to the value of delta-H for the reverse reaction.  Thirdly, the heat of formation for any element in its standard state is zero.

Quantum Numbers

Now, we shall look at the quantum numbers.  According to quantum mechanics, the state of an electron in an atom is specified by four quantum numbers-n, l, m_l and m_s.  The principle quantum number, n, can take any integer value-one, two, three, etc.  l, the orbital quantum number can take on values from zero up to n^-1. m_l the magnetic quantum number can take on integer values from ^-l to ⁺l.  And m_s, the magnetic spin quantum number can be either ⁺ ½ or - ½.

The energy levels in the hydrogen atom depend on n whereas in other atoms, they depend on n and l.  When an external magnetic field is applied, the spectral lines are split, indicating that the energy depends also on m_l.  Even in the absence of a magnetic field, precise measurements of spectral lines show a tiny splitting of the lines called fine structure, whose explanation is that the energy depends very slightly on the spin quantum number m_s.

Pauli Exclusion Principle

The arrangement of electrons in multi^-electron atoms is governed by the Pauli Exclusion Principle, which states that no two electrons can occupy the same quantum state.  That is, they cannot have these same set of quantum numbers n, l, m_l and m_s.  The electrons as a result are grouped into shells according to the value of n and subshells according to the value of l.  This shell structure gives rise to a periodicity in the properties of the elements.

Chemical Bonds

Now, we shall look at chemical bonds.  Ionic bonding results from the complete transfer of electrons from one atom to another with formation of a three dimensional lattice of charged particles.  The stabilities of ionic substances result from the powerful electrostatic attractive forces between an ion and all these surrounding ions of opposite charge.  They call anions are negative ions, while cations are positive.  These interactions are measured by the lattice energy.

Covalent bonding results from the sharing of electron between atoms.  The rules that govern this sharing are based on the stability of the noble gas electron configuration.  This is called the Octet Rule.  We can represent shared electron pair structures of molecules by means of Lewis structures, which show the sharing of electron pairs between atoms.

The sharing of one pair of electron produces a single bond.  The sharing of two or three pairs of electrons between atoms produces double and triple bonds, respectively.  It sometimes happens that a single Lewis structure is inadequate to represent a particular molecule.  But then an average of two or more Lewis structures does form a satisfactory representation.

Lewis Structures and Resonance Forms

In these cases, the Lewis structures are referred to as Resonance Forms.  It also sometimes happens that the Octet Rule is not obeyed.  This situation occurs mainly when a large atom is surrounded by small electronegative atoms, like fluorine, oxygen or chlorine.  In such instances, the large atom often has more than an octet of electrons.

The strength of covalent bonds increase with the number of electron pairs shared between two atoms.  In single bonds, the bond strings are generally higher between atoms of smaller size.  It is important to recognize that even in covalent bonding electrons may not be shared equally between two atoms.

Electronegativity

Electronegativity is a measure of the ability of an atom to compete with other atoms for the electrons shared between them.  Highly electronegative elements strongly attract electrons.  The electronegativities of the elements which show regular periodic relationship are an important guide to chemical behavior.  The difference in electronegativities of bonded atoms is used to determine of the polarity of the bond.

Another application of electronegativity is in the assignment of oxidation numbers which are formal whole number charges assigned to atoms in molecules and ions.  Although the oxidation numbers do not represent the real charges on atoms except in simple ionic substances, they are of great value in helping us to organize chemical facts and are in aid in balancing equations and in the naming of compounds.

Oxidation Number

Oxidation may be defined as the process in which an atom undergoes an increase in oxidation number.  Reduction is a process in which an element undergoes a decrease in oxidation number.  In an oxidation^-reduction reaction, both oxidation and reduction occur in such a manner as to balance the total increases and decreases in oxidation numbers.

Stoichiometry

Chemical bonds and shapes.  The three dimensional structures of molecules are determined by the distances between bonded atoms and by the directions of chemical bonds with the respect to one another around a particular atom.  The Valence shell electron pair repulsion model explains these relative directions in term of the repulsions that exist between electron pairs.

Electrostatic Repulsions

According to this model, electron pairs around an atom orient themselves so as to minimize electrostatic repulsions.  That is, they remain as far apart as possible.  By recognizing the unshared electron pair take up more space, i.e. they exert greater repulsive forces then shared electron pairs, it is possible to account for the departures of bond angles from the ideal^-like values and to explain many other aspects of molecular structure.  The shape of a molecule and the bond polarities determine whether or not a molecule will be polar.  The degree of polarity of a molecule is measured by its dipole moment.

The Lewis model for covalent bonding can be extended to account very nicely for the geometrical properties of molecules.  We can imagine that the atoms in a molecule are bonded to one another by electron pairs that occupy pairs of overlapping atomic orbitals.  The extent to which the atomic orbitals share the same region of space, called overlap, is important in determining the amount of stability that results from bond formation.

Sigma (Single) Bonds

The bonds directed along the internuclear axes are called sigma bonds, sigma bonds or single bonds.  It is possible to formulate orbitals on an atom that are directed toward each of the other atoms surrounding it by forming a hybrid orbital.  These orbitals are made up of mixtures of the familiar SPND atomic orbitals.  Depending on the particular number of other atoms bonded to an atom and their arrangement in space, a particular set of hybrid orbitals can be formulated that has the necessary directional characteristics.

For example, SP3 hybrid orbitals are directed towards the corners of a tetrahedron.  In addition to the sigma bonds which determine the geometry of the bonding around a particular atom, there are also pi bonds constructed from remaining unhybridized atomic orbitals.  Thus, double bonds consisting of a sigma and a pi bond, or triple bonds consisting of a sigma and two pi bonds may be formed.  In some molecules, the pi bond may extend or be delocalized over several atoms.

Delocalization of the pi electron in a cyclic structure, such as in benzene or throughout a plane, leads to a special stability.  The coming together of atoms to form molecules may be viewed also as the coming together of the atomic orbitals to from molecular orbitals.  Atomic orbitals may combine with one another in various ways.  The rules for combining atomic orbitals on atoms to form molecular orbitals allow us to account very well for the observed properties of the diatomic molecules formed by the first several elements of the periodic table.

Properties of gases

To describe the state or condition of a gas, it is necessary to specify four variables-pressure, temperature, volume, and the quantity of the gas.  Volume is usually measured in liters and temperature in the Kelvin scale.  Pressure is defined as the force per unit area.  It is expressed in the SI unit as Pascals, where one Pascal is equal to one Newton per meter squared, which in turn is equal to one kilogram per meter second squared.  Pressure can also be defined in millimeters of mercury.  One standard atmosphere of pressure equals 101.3 kilopascals or 760 millimeter of mercury.  A barometer is often used to measure the atmospheric pressure.

The ideal gas equation

PV=nRT

Where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and t is the Temperature in Kelvin.

Most gases at pressures of about one atmosphere and temperatures of 300 Kelvin and above obey the ideal gas equation reasonably well.  We can use the ideal gas equation to calculate variations in one variable when one or more of the others are changed.

Boyle’s Law

For a constant quantity of gas at constant temperature, the pressure of the gas is inversely proportional to the volume.  That is Boyle’s law.

Charles’ Law

Similarly for a constant quantity of gas at constant pressure, the volume of a gas is directly proportional to temperature.  That is Charles’ law.

Dalton’s Law of Partial Pressures

In gas mixtures, the total pressure is the sum of the partial pressures that each gas would exert if it were present alone under the same conditions.  That is the Dalton’s law of partial pressures.  In all applications of the ideal gas equation, we must remember to convert temperature to the absolute temperature scale, in Kelvin.  It is important to be able to use the ideal gas equation to solve problems involving gases as reactants or products in chemical reactions.

Molecular Weight of Gas

From the gas density, rho, under given conditions of pressure and temperature, it is possible to calculate the molecular weight of the gas, where molecular weight will, therefore, be equal to rho rt/p, this can be derived from PV=nRT.  As long as you remember that the density is equal mass divided by volume.

Density = Mass / Volume

In calculating the quantity of gas collected over water, correction must be made for the partial pressure of water vapor in the container.

Kinetic Molecular Theory (analagous to Brownian Motion)

The kinetic molecular theory accounts for the properties of an ideal gas in terms of a set of assumptions about the nature of gases.  Briefly, these assumptions are that molecules are in ceaseless, chaotic motion, that the volume of gas molecule is negligible in relation to the volume of their container, that the gas molecules have no attracted forces for one another, and finally, that the average kinetic energy of the gas molecules is proportional to absolute temperature.

The molecules of a gas do not all have the same kinetic energy at a given instance.  Their speeds are distributed over a wide range.  The distribution varies with the molecular weight of the gas and with the temperature.  The root mean square speed varies in proportion to the square root of absolute temperature and inversely with the square root of molecular weight.  It follows that the rate at which a gas escapes or effuses through a tiny hole is inversely proportional to the square root of its molecular weight.

Non-Ideal Gases

Molecules in a real gas posses finite volume and, thus, undergo frequent collisions with one another.  These frequent collisions will limit the rate at which a gas molecule can diffuse through a space occupied by other gas molecules and determine the thermal conductivity of the gas.  The extent of non ideality of a real gas can be seen by examining the quantity PV over RT for one mole of a gas as a function pressure.  This quantity is exactly equal to one for an ideal gas at all pressures.

Real gas will depart from ideal behavior because the molecules possess finite volume or because the molecules experience attractive forces from one another upon collision.  The van der Waals equation is an equation of state for gases that attempts to correct the ideal gas equation to take into account the two properties of real gases.

Solutions-solutions are homogenous mixtures of atoms, ions, or molecules.  The relative amounts of solute and solvent in a solution can be described qualitatively-dilute or a concentrated solution, or quantitatively, as in weight percentage; molarity, which is moles per liter; molality, which is moles solute per kilogram solvent; normality, equivalence per liter; or mole fraction.  Mole fraction is the ratio of the number of moles of one component of a solution to the total number of moles of all substances present.

The extent to which a solute will dissolve in a particular solvent depends on the relative magnitudes of solute^-solute or solute^-solvent, and solvent^-solvent attractive forces, as well as the - it depends on the changes in disorder accompanying the mixing.  The rule, like dissolves like is found to be useful in rationalizing solubilities.  It is possible to chain the solubility of a solute by changing temperature and pressure.  If the solution process is endothermic, an increase in temperature promotes solubility.  With a gas, an increase in pressure promotes solubility.

Le Chatelier’s Principle

These effects can be understood in terms of Le Chatelier’s principle.  Substances that exist in solution as ions are called electrolytes.  Those substances that are completely ionized in solution are called strong electrolytes.  Reactions occur between electrolytes if an insoluble substance, a gas or a non^-electrolyte conforms.  Net ionic equations focus attention on the particular species that actually undergo some change during the reaction.

The presence of a solute in a solvent lowers the vapor pressure and the freezing point, and increases the boiling point of the solvent.  These changes are termed colligative properties.  The magnitude of the change depends on the total concentration of solute particles in solution, and not on there characteristics.

Acids and Bases

Acids and bases-an acid solution is created when a substance reacts with water in such a way as to increase the concentration of solvated hydrogen ions, which are represented as H⁺ or H₃O⁺.  The concentration of H⁺ is often expressed on the pH scale, where pH equals negative log concentration of hydrogen ions.  Solutions of pH less than seven are acidic.  Those with pH greater than seven are basic.

Ionization of Water

Water spontaneously ionizes to a slight degree, forming H⁺ and OH^-.  The extent of ionization is expressed by the ion product constant for water, which is Kw, which is equal to a concentration of a H⁺ times the concentration of OH^-, which is equal to 10 to the minus 14.  This relationship describes not only pure water but aqueous solution as well.  Because the concentration of water is effectively constant in dilute solutions, the concentration of water is omitted from this equilibrium constant expression as well as from others associated with reactions in aqueous solutions.

Bronsted-Lowry Theory

One can rely on the Bronsted-Lowry theory of acids and bases.  According to this theory, an acid is a proton donor, or a base is a proton acceptor.  Reaction of an acid with water results in the formation of H⁺ and the conjugate base of the acid.  Strong acids have conjugate bases that are weaker than water.  Such acids are strong electrolytes, ionizing completely in solution.  The common strong acids are HCl, HBr, HI, HNO₃, HClO₄, and H₂SO₄.  Weak acids are substances for which the reaction with water is incomplete and equilibrium is established.

Dissociation Constants

The extent to which the reaction proceed is expressed by the acid dissociation constant K_a.  Polyprotic acids are acids such as H₂SO₃ that have more than one ionizable proton.  Aside from the ionic hydroxides, such as NaOH, base is produced an increase of OH^- by reaction with water.  Strong bases have conjugate acids that are no stronger than water.  The common strong bases are the hydroxides and oxides of the alkali metals and alkaline earth.  Weak bases include H₂O, NH₃, amines, and the anions of weak acids.  The extent to which a weak base reacts with water to generate OH^- and a conjugate acid of the base is measured by the base dissociation constant, K_b.

Biology for the MCAT

Classes of Organic Molecules

Four major classes of organic molecules found in living organisms are carbohydrates, fats, proteins, and nucleic acids.

Condensation Reactions

Though these classes of molecule have different structure and function, they are built up of many similar building block molecules bonded together. In each case, building block molecules are combined by the removal of water, and this is called “condensation reactions.”

Condensation reactions are reversible. The complex organic molecules can be hydrolyzed into the simpler building blocks molecules with the addition of water. The basic building block molecules of carbohydrates are the simple sugars or monosaccharides.

Disaccharide Bonds

When two simple sugars are bonded together, a disaccharide is formed. When many simple sugars are bonded together in long chains, a polysaccharide is formed. Starch, glycogen, and cellulose are examples of polysaccharides.

The carbohydrates are an important energy source for all organisms. Lipids, the fats, and fat-like substances tend to be insoluble in water. Fats are made up of two building block molecules – glycerol and fatty acids. Phospholipids are derived from the fats. They are important constituents of cell membranes.

Peptide Bonds

The basic building block molecules of the proteins are amino acids. Amino acids are bonded together to form a protein by condensation reactions. The resulting bond is the peptide bond and the chains produced are polypeptide chains. The primary structure of each protein is the sequence and type of amino acids making up the polypeptide chains.

Because hydrogen bonds form between one amino acid and another, the chain assumes a stable regular shape known as the secondary structure. These regular molecules may in turn be folded into complicated globular shapes by weak attractions between the different R groups within the chain, thus forming the tertiary structure of the protein.

Nucleotide Bonds

Some globular proteins are made up of two or more polypeptide chains held together by weak bonds. The way these chains fit together determines the ordinary structure. Because the conformation of a protein depends on weak bonds, it is easily altered causing a change in biological function.

The building block unit of nucleic acids is the nucleotide, which is made up of a five carbon sugar attached to a phosphate group and to a nitrogen-containing base. Nucleotide units are joined together through condensation reactions between the sugar of one nucleotide and the phosphate group of the next.

There are four different nucleotides in each nucleic acid. It is the different sequences of the nucleotides that encode their hereditary information. The two types of nucleic acids, DNA and RNA, differ in their basic make up and in the number of strands in the molecule. We will be discussing this in greater detail later.

Free Energy and Enzymes

Chemical reactions that release free energy are exothermic or exergonic. Reactions that require the addition of free energy are endothermic or endergonic. In living systems, an exothermic reaction is usually coupled with an endothermic reaction. Although exothermic reaction proceeds spontaneously, initiating a reaction may require an activation energy.

Chemical reactions can be speeded up by heat, by increasing the concentrations of the reactants, or by providing the appropriate catalyst. In living systems, the catalysts are enzymes. Most enzymes are highly specific and each can interact only with those reactants or substrates that fit spatially and chemically into the active site of the enzyme.

Since the formation of the enzyme, substrate complex requires the enzyme and the substrate to be complementary. Anything that alters the shape of the enzyme will alter its activity. In addition to temperature and pH, many chemical substances can mask, block or alter the shape of the enzyme and its active site.

The Biological Cell

Now, let us discuss cells. The fundamental organizational unit of life is the cell. Most cells are very small and have a large ratio of surface area to volume so they can effectively exchange materials like oxygen, nutrients, and waste with the surrounding environment.

Plasma Membrane

Cells are bounded by a plasma membrane composed of lipids and proteins with many small pores. According to the fluid mosaic model, the plasma membrane consists of a bi-layer of phospholipids with their hydrophilic heads oriented towards the surfaces of the membrane and their hydrophobic tales toward the interior.

Protein Channels

The proteins are distributed both on the surfaces and in the interior of the membrane. The pores are thought to be bounded by protein. The distinctive properties of these proteins make the pore selective as to what can move through them. The cell membrane is an active part of the cell. It regulates the movement of materials between the ordered interior of the cell and their outer environment.

Passive Transport

This type of molecular passage from one side of a membrane to another requires no external energy. This is governed by charge and osmolality balance, which are intrinsic properties of solutions.

Diffusion

The general rule is that the net movement of particles of a particular substance is from regions of higher concentration to regions of lower concentration of that substance. This movement of particles is called “diffusion.” The plasma membrane is differentially permeable. It allows particles of some substances to pass through while excluding others.

Osmosis

The movement of water through a plasma membrane is called “osmosis.” Cell membranes are relatively permeable to water and to certain simple sugars, amino acids and lipid soluble substances. They are relatively impermeable to polysaccharides, proteins and other very large particles. Their permeability to small particles varies.

Facilitated Diffusion

The bilipid layer presents a barrier to substances insoluble in lipids. For such substances, some protein components of the membrane function as carrier molecules called “permeases.” In facilitated diffusion or passive transport, the substances being carried move with the concentration gradient and no energy is required.

Active Transport

In active transport, substances are moved against a concentration gradient; hence, the cell must expend energy. Sometimes substances are taken into the cell by an active process called “endocytosis.” The reverse sequence is called “exocytosis.” The cell membrane cannot completely regulate the exchange of materials.

A cell in a medium that is hypertonic, meaning higher osmotic concentration, relative to it tends to loose water and shrinks. Conversely, a cell in a hypotonic medium lower osmotic concentration relative to it tends to gain water and swell and may even burst. A cell in an isotonic medium, osmotic concentrations in balance neither gains nor looses appreciable water.

Sub-Cellular Components

Cell Walls

Fungi and bacteria have cell walls made not of cellulose but of other complex polysaccharide molecules.

Glycocalyx

Most animal cells have a cell coat of carbohydrates covalently bonded to protein or lipid molecules in the plasma membrane. This coat is called a “glycocalyx.” Eukaryotic cells have membrane-bound nucleus; whereas, prokaryotic cells – for example, bacteria – lack a membrane-bound nucleus.

Chromosomes

The nucleus contains the chromosomes which contain the genes. It can therefore direct the cell’s life processes. Separating the nucleus from the cytoplasm is a double nuclear membrane interrupted by pores.

Endoplasmic Reticulum

The nuclear membrane is continuous at places with the endoplasmic reticulum. The endoplasmic reticulum forms a system of interconnected membrane enclosed spaces. Sometimes the membranes of the endoplasmic reticulum are rough with ribosomes on their outer surfaces. When no ribosomes are present, the endoplasmic reticulum is smooth. Ribosomes are sites of protein synthesis.

The endoplasmic reticulum functions both as a passageway for intracellular transportation and as a manufacturing surface. The Golgi apparatus consists of stocks of membrane-bound vesicles that function in the storage, modification, and packaging of secretory products.

Cytoplasm

Mitochondria

Located within the cytoplasm are many other organelles. The mitochondria are the power houses of the cell. Chemical reactions within the mitochondria provide energy for the activities of the cell.

Lysosomes

Lysosomes are membranous sacs that function as storage vesicles for powerful digestive enzymes. They may act as the cell’s digestive system, hydrolyzing materials taken in by endocytosis.

Microtubules

Microtubules and microfilaments appear to function in intracellular movement and cell support. Microtubules also form the spindle of dividing cells and are the essential components of centrioles, cilia, and flagella.

Cellular metabolism

Cellular metabolism is a general term embracing the myriad of enzyme-mediated reactions of a living cell. It can be divided into two phases: anabolism – the building up phase – and catabolism – the breaking down phase.

Before the potential energy is stored in complex organic compounds, it can be used by the cell to do work. The compounds must be broken down in a series of chemical reactions and the energy transferred to ATP.

Glycolysis

The first series of reactions in the degradation of glucose is termed glycolysis. It is the breakdown of glucose to two molecules of Pyruvic acid with the production of two molecules of NADH, a net gain of two ATP molecules. This process common to all living cells is anaerobic, meaning oxygen is not needed.

Fermentation

The fate of the Pyruvic acid depends on the oxygen supply. In the absence of sufficient oxygen, the Pyruvic acid maybe reduced by NADH to form carbon dioxide and ethyl alcohol or lactic acid in a process called “fermentation.” NAD molecules, thus formed, are available to be reused in glycolysis.

Cellular Respiration

Under aerobic conditions, the Pyruvic acid can be further oxidized with the accompanying synthesis of ATP. This process is called cellular respiration.

Kreb’s Cycle

The process begins with the breakdown of two Pyruvic acid molecules to form two molecules each of acetyl coenzyme-A, carbon dioxide, and NADH. The acetyl coenzyme-A is fed into the Krebs’ citric acid cycle. In the course of this cycle, two carbons are lost as carbon dioxide, a molecule of ATP is synthesized, and eight hydrogens are removed and picked up by carrier compounds forming three molecules of NADH and one of FADH too.

Since one molecule of glucose gives rise to two molecule of acetyl coenzyme-A, two turns of the cycle occur for each molecule of glucose oxidized. The final stage of respiration involves the passage of the hydrogen electrons from the carrier molecules down a respiratory chain of electron transport molecules down to oxygen with which the electrons and hydrogen ions from the medium combine to form water.

Oxidative Phosphorylation

As the electrons are lowered step-by-step down the energy grade end, energy is released and some of it is used to make ATP. This process is called “oxidative phosphorylation.” The total number of new ATP molecules produced by the complete metabolic breakdown of glucose is usually 36 :

• 2 from glycosis
• 2 from the Krebs cycle
• 32 from the electron transport chain.

Cellular respiration captures about 38% of the energy of glucose and converts it into ATP. The rest of the energy is released mostly as heat. Most animals turned “poikilothermic” and all plants promptly lose most of this heat to their environment.

Temperature Regulation

The body temperature and metabolic rate of poikilotherms fluctuates with the environmental temperature. A few animals, homoeothermic maintain a constant high-body temperature. Their metabolic rate can accordingly be maintained at a uniformly high level.

Humans are examples of homeotherms. We will now examine circulatory and lymphatic systems. The closed circulatory system of the human is composed of a heart, arteries, veins, and capillaries. The actual exchange of materials between blood and other tissues takes place in the capillaries. The human heart is a double pump. Each side divided into two chambers—an upper atrium, which receives blood and pumps it into the lower chamber; and the lower ventricle which then pumps the blood away from the heart.

The Human Circulatory System

The right heart receives deoxygenated blood from all over the body and pumps it via the pulmonary arteries to the lungs where it picks up oxygen and gives up carbon dioxide. The oxygenated blood then returns to the left atrium by the pulmonary veins. This portion of the circulatory system is called the “pulmonary circulation”. The left ventricle pumps the blood into the aorta and its numerous branches from which it moves into capillaries where the exchange of materials takes place, then into veins and finally back via the superior or inferior vena cava to the right side of the heart.

This portion of the circulatory system is called the “systemic circulation.” The heartbeat is initiated when a wave of contraction spreads out from the SA node to the AV node, which sends excitatory impulses down the Bundle of HIS stimulating both ventricles to contract. During systole, the blood is forced out of the heart and into the arteries under high-pressure.

Blood Pressure

During diastole, the blood pressure in the arteries falls. One-way valves and skeletal muscle action aid in moving blood in the veins. When you hear that someone has a blood pressure of 120/80, which is normal – 120 represent the pressure in the arteries during systole in millimeters of mercury.

The 80 in 120/80 represents diastole, the blood pressure during diastole in millimeters of mercury. The movement of materials into and out of capillaries is governed by the balance between hydrostatic blood pressure and osmotic pressure. The lymphatic system helps maintain the osmotic balance of the body fluids by returning excess tissue fluid and proteins to the blood.

Lymph nodes act to filter up particles and also a site of formation/maturation of some white blood cells. Blood consists of plasma, the liquid portion and formed elements, which are the red blood cells, white blood cells, and platelets. Blood clotting is initiated when damage tissue and disintegrating platelets release thromboplastin, which converts the plasma protein, prothrombin into thrombin.

The thrombin then converts fibrinogen into fibrin which forms the clot; thus fibrin forms the clot. The erythrocytes contain the oxygen-carrying pigment hemoglobin, which transports oxygen from the lungs to the tissues.

Most carbon dioxide is carried in the form of the bicarbonate ion HCO3-. The leukocytes defend the body against disease and infection. Some leukocytes carry on phagocytosis. Others produce enzymes that detoxify dangerous substances, and still others produced antibodies that destroy or inactivate certain kinds of foreign substances called “antigens.”

The Endocrine System

The endocrine system, the tissues that produce and release hormones in animals are termed “endocrine tissues.” The hormones are secreted more or less directly into the blood, which then transports them to other parts of the body.

Insulin

The pancreas secretes insulin and glucagon, which regulate the blood sugar level. Insulin acts to reduce the blood glucose concentration. Glucagon causes an increase in the blood glucose concentration. The two adrenal glands located above the kidneys consist of an inner medulla and an outer cortex, which remain functionally distinct.

Epinephrine and Norepinephrine

The adrenal medulla secretes two hormones—adrenalin and noradrenalin. Both help to prepare the body for emergencies by stimulating reactions that increase the supply of glucose and oxygen to the skeletal and heart muscles. This is sometimes called the “fight-or-flight responds.”

Glucocorticoids and Mineralcorticoids

The adrenal cortex produces many different steroid hormones which may be grouped into three functional categories—one, those regulating carbohydrate and protein metabolism, the glucocorticoids; two, those regulating salt and water balance, i.e., the mineralocorticoids; and three, those that function as sex hormones.

Thyroxine

The thyroid gland is located just below the larynx. Two of the hormones it secretes are thyroxin and triiodothyronine. These two thyroid hormones stimulate the oxidative metabolism of most tissues in the body; thus, they increase the metabolic rate.

Calcitonin and Parathyroids Hormone

The thyroid also secretes calcitonin which prevents the excessive rise of calcium ions in the body. The parathyroids are four small P-like organs located on the surface of the thyroid. The parathyroid hormone, sometimes called “parathormone,” regulates the calcium phosphate balance between the blood and other tissues.

It acts primarily on the kidneys, the intestines, and the bones. The posterior pituitary is connected to the hypothalamus by a stalk. It stores and releases two hormones—oxytocin and vasopressin, which are produced in the hypothalamus and flow along nerves in the stalk to the posterior pituitary.

Oxytocin

The hormones are released upon nervous stimulation from the hypothalamus. Oxytocin stimulates the contraction of uterine muscles. Vasopressin causes constriction of the arterioles with a consequent rise in blood pressure. Vasopressin also stimulates the kidney tubules to reabsorb more water. The anterior pituitary produces many hormones with far reaching effects. Prolactin stimulates milk production by the mammory glands and also participates in reproduction, osmoregulation, growth, and metabolism of carbohydrates and fats.

Growth Hormone

Growth hormone promotes normal growth. The anterior pituitary also secretes a number of hormones that help control other endocrine organs. Thyrotrophic hormone stimulates the thyroid gland. Adrenocorticotropic hormone stimulates the adrenal cortex and the two gonadotropic hormones – FSH and LH – act on the gonads. The interaction between these glands and the anterior pituitary is an example of negative feedback. The activity of the anterior pituitary is in-tern regulated by the hypothalamus, which produces special peptide releasing hormones or releasing factors. These hormones are carried by portal system to the anterior pituitary where they stimulate its secretory activity. Therefore, the hypothalamus is the point at which information from the nervous system influences the endocrine system and is also one of the major sites of feedback from the endocrine system.

The Nervous System

The nervous system, the typical neuron consist of the cell body, which contains the nucleus, and one or more long nerve fibers call “axons” and “dendrites” that extend from the cell body. Sensory neurons lead from receptor cells. Motor neurons lead to effector cells and interneurons lie between the sensory and motor neurons.

Junctions between neurons are called “synapses.” A reflex arc is a simple neural pathway linking a receptor and an effector. Most somatic reflex arcs begin with a sensory neuron that conducts the impulse to interneurons in the spinal cord. These in turn synapse with motor neurons in the cord. And the impulses are conducted to the effectors usually skeletal muscles, which respond to the stimulus. Reflex arcs always inter connect with other neural pathways.

A nerve consists of a number of neuron fibers bound together. The autonomic nervous system consists of nervous pathways that conduct impulses from the central nervous system to various internal organs. These pathways usually involve to motor neurons. The autonomic nervous system regulates the body’s involuntary activities. There are two divisions of the autonomic nervous system—the sympathetic and parasympathetic systems. The sympathetic system associated more with fight-or-flight responses and the parasympathetic system associated more with vegetative responses.

Most internal organs are innervated by both with the two systems usually functioning in opposition to each other. A nerve impulse is a wave of electrochemical change moving along and their fiber. The potential stimulus must be above a particular threshold to initiate an impulse. If the axon fires, it will fire maximally or not at all. This is called the “all-or-none response.” The inside of a resting nerve fiber is negative with respect to the outside. When a fiber stimulated, sodium ions rush into the cell making the inside positively charge relative to the outside. And instant later, potassium ions, which are in higher concentration inside the cell, rush out of the cell restoring the original charge. This cycle of changes is called the “action potential.” A sodium potassium pump, ATPase pump, restores the original ion distribution.

When an impulse traveling along the axon reaches the synaptic boutton, it causes the synaptic vesicles to discharge their stored transmitter chemical into the cleft. The transmitter molecules diffuse across the cleft and alter the membrane potential of the next neuron. Synaptic transmission is slower than impulse conduction along the neuron.

Renal Physiology

A. ECF/ICF

ECF (1/3) = extracellular fluid of two compartments – vascular (1/3) and interstitial (2/3)

ICF (2/3) = intracellular fluid compartment

Example: how many liters of isotonic saline do you have to infuse to get 1 liter into the plasma? 3 Liters (2/3:1/3 relationship); 2 liters in interstial space, and 1 L would go to the vascular space; it equilibrates with interstial/vascular compartments.

B. Osmolality =

Measure of solutes in a fluid; due to three things: Na, glucose, and blood urea nitrogen (BUN) – urea cycle is located in the liver, partly in the cytosol and partly in the mitochondria; usually multiply Na times 2 (b/c one Na and one Cl). Normal Na is 135-140 range, times that by 2 that 280. For glucose, normal is 100 divide that by 18, let’s say it’s roughly 5, so that’s not contributing much. BUN:  located in the liver, part of the cycle is in the cytosol and part of it is in mitochondria. The urea comes from ammonia, that’s ammonia is gotten rid of, by urea. B/c the end product of the urea cycle is urea. The normal is about 12; divide that by 3, so we have 4. Therefore, in a normal person Na is controlling the plasma osmolality. To measure serum osmolality: double the serum Na and add 10.

C. Osmosis =

Among intracellular, intravascular, and interstitial spaces, 2 of these 3 are limited to the ECF compartment. One can equilibrate between ECF and ICF across the cell membranes – urea; therefore, with an increased urea, it can equilibrate equally on both sides to it will be equal on both sides; this is due to osmosis.

B/c Na and glucose are limited to the ECF compartment, then changes in its concentration will result in the movement of WATER from low to high concentration  (opposite of diffusion – ie in lungs, 100 mmHg in alveoli of O2, and returning from the tissue is 40 mmHg pO2; 100 vs. 40, which is bigger, 100 is bigger, so via diffusion, O2 moves through the interspace into the plasma to increase O2 to about 95mmHb). Therefore, in diffusion, it goes from high to low, while in osmosis, it goes from low to high concentration.

1. Hyponatremia

Example: In the case with hyponatremia – water goes from ECF into the ICF, b/c the lower part is in the ECF (hence HYPOnatremia); water goes into the ICF, and therefore is expanded by osmosis. Now make believe that the brain is a single cell, what will we see? cerebral edema and mental status abnormalities via law of osmosis (the intracellular compartment of all the cells in the brain would be expanded)

2. Hypernatremia

Example: hypernatremia – water goes out of the ICF into the ECF, therefore the ICF will be contracted. So in the brain, it will lead to contracted cells, therefore mental status abnormalities; therefore, with hypo and hypernatremia, will get mental status abnormalities of the brain.

3. Diabetic ketoacidosis

Example: DKA – have (1000mg) large amount blood sugar. Remember that both Na and glucose are limited to the ECF compartment. You would think that glucose is in the ICF but it’s not. You think that since glycolysis occurs in the cytosol therefore glucose in the ICF (again its not) b/c to order to get into the cell (intracellular), glucose must bind to phosphorus, generating G6P, which is metabolized (it’s the same  with fructose and galactose, which are also metabolized immediately, therefore, there is no glucose, fructose, or galactose, per se, intracellularly). So, with hyperglycemia, there is high glucose in the ECF, so water will move from ICF to ECF. Therefore, the serum Na concentration will go down – this is called dilutional hyponatremia (which is what happens to the serum sodium with hyperglycemia).

Therefore the two things that control water in the ECF are Na and glucose; but a normal situation, Na controls. Urea does not control water movements b/c its permeable, and can get through both compartments to have equal concentrations on both sides.

D. Tonicity =

Isotonic state, hypotonic state, and hypertonic state. We have all different types of saline: Isotonic saline, hypotonic saline (1/2 normal saline, ¼ normal saline, 5% dextrose in water), and  hypertonic saline (3%, 5%); normal saline is 0.9%. We are referring to normal tonicity of the plasma, which is controlled by the serum Na. These are the three types of tonicity (iso, hypo, and hyper). Serum Na is a reflection of total body Na divided by total body H20. For example: hypernatremia is not just caused by increased total body Na; it can also be caused by decreasing total body water with a normal total body Na, therefore there is an increase in serum Na concentration. It is really a ratio of total body Na to total body H20. To determine serum Na, just look at serum levels. With different fluid abnormalities, can lose or gain a certain tonicity of fluid.

1. Isotonic loss of fluid

– look at ratio of total body Na and water; in this case, you are losing equal amounts of water and Na, hence ISOtonic. This fluid is mainly lost from the ECF. The serum Na concentration is normal when losing isotonic fluid. ECF would look contracted. There would be no osmotic gradient moving into or out of the ECF. Clinical conditions where there is an isotonic loss of fluid: hemorrhage, diarrhea. If we have an isotonic gain, we have in equal increase in salt and water; ie someone getting too much isotonic saline; normal serum Na, excess isotonic Na would be in the ECF, and there would be no osmotic gradient for water movement.

2. Hypotonic solutions

A hypotonic solution, by definition, means hyponatremia. Hypoglycemia will not produce a hypotonic condition.

MCC of low osmolality in plasma is hyponatremia. How? Lose more salt than water, therefore, serum Na would be decreased. If losing more salt than water, kidney is probably the location of where/why it is happening. Main place to deal with sodium (either to get rid of it or to get it back) is in  kidney, esp when dealing with diuretics (Furosemide and HCTZ). The tonicity of solution you lose in your urine is HYPERtonic, so that’s how you end up with hyponatremia with a hypotonic condition. ECF concentration is low with hyponatremia, therefore the water will move into the ICF compartment. (Osmosis-remember low to high)

Syndrome of Inappropriate Andidiuretic Hormone (SIADH):

Example: If you gained pure water, and no salt, you have really lowered your  serum Na:  MCC = SIADH – in small cell carcinoma of the lung; you gain pure water b/c ADH renders the distal and the collecting tubule permeable to free water. With ADH present, will be reabsorbing water back into the ECF compartment, diluting the serum Na, and the ECF and ICF will be expanded. The ECF is expanded due to water reabsorption, and the ICF is expanded b/c it has a high concentration levels (its levels are not diluted). This can lead to mental status abnormalities. Therefore, the more water you drink, the lower your serum Na levels would be. The treatment is by restricting water. Don’t want to restrict Na b/c  the Na levels are normal. When ADH is present, you will CONCENTRATE your urine b/c taking free water out of urine; with absent ADH, lose free water and the urine is diluted. Therefore, for with SIADH, water  stays in the body, goes into the ECF compartment, and then move into the ICF compartment via osmosis. The lowest serum sodium will be in SIADH. On the boards, when serum Na is less than 120, the answer is always SIADH. Example: pt with SIADH, not a smoker (therefore not a small cell carcinoma), therefore, look at drugs – she was on chlorpropramide, oral sulfylureas produce SIADH.

Right Heart Failure and Hepatic Cirrhosis:

Example: Gain both water and salt, but more water than salt, leading to hyponatremia – these are the pitting edema states – ie RHF, cirrhosis of the liver. When total body Na is increased, it always produces  pitting edema. What compartment is the total body Na in? ECF What is the biggest ECF compartment? Interstial compartment. Therefore, increase in total body Na will lead to expansion of interstial compartment  f the ECF, water will follow the Na, therefore you get expansion via transudate and pitting edema; seen in right HF and cirrhosis.

• Example: hypertonic loss of salt (from diuretic) leads to hyponatremia
• Example: SIADH (gaining a lot of water) leads to hyponatremia
• Example: gaining more water than salt will lead to hyponatremia: pitting edema

3. Hypertonic state

A hypertonic solution, by definition means too much Na (hypernatremia) or hyperglycemia. Unlike in a hypotonic solution, you can have glucose contribute to this state. For example, a patient with DKA has a hypertonic condition, which is more common than hypernatremia. With hypernatremia,  what does ICF look like? It will always be contracted or shrunken.

Primary aldosteronsim

Gain more salt and water.

Diabetes insipidus

Lose pure water (vs. gaining pure salt in SIADH). If you lose more water than salt in the urine, you have osmotic diuresis – mixture. When there is glucose and mannitol in the urine, you’re losing hypotonic salt solution in urine.

Infant diarrhea

Hypotonic salt solution (adult diarrhea is isotonic), therefore, if baby has no access to water and has a rotavirus infection, serum sodium should be high because losing more water than salt, leading to hypernatremia. However, most moms give the baby water to correct the diarrhea; therefore the baby will come in with normal serum Na or even hyponatremia b/c the denominator (H2O) is increased. Treatment is pedialyte and Gatorade – these are hypotonic salt solution (just give them back what they lost). What has to be in pedialyte and what has to be in Gatorade to order to reabsorb the Na in the GI tract? Glucose b/c of the co-transport. With the co-transport, the Na HAS to be reabsorbed with glucose or galactose. Example: cholera, in oral replacement, need glucose to reabsorb Na b/c co-transport pump located in the small intestine. Gatorade has glucose and sucrose (which is converted to fructose and glucose).

Sweat

Hypotonic salt solution; if you are sweating in a marathon, you will have hypernatremia.

E. Volume Compartments

Physiologic response to hypovolemia:

Arterial blood volume is same as stroke volume and CO (cardiac output). When Cardiac Output decreases, all physiologic processes occur to restore volume. With decrease CO (ie hypovolemia), oxygenated blood will not get to tissues, and we can die. Therefore, volume is essential to our bodies.

1. Baroreceptors

We have baroreceptors (low and high pressure ones). The low pressure ones are on the venous side, while the high pressure ones are on the arterial side (ie the carotids and arch of aorta). They are usually innervated by CN 9 and 10 (the high pressure ones). When there is a decrease in arterial blood volume (decreased SV or CO), it will under fill the arch vessels and the carotid; instead of 9th or 10th nerve response, you have a sympathetic NS response, therefore catecholamines are released. This is good b/c they will constrict the venous system, which will increase blood returning to the right side of the heart (do not want venodilation b/c it will pool in your legs).

2. Catecholamines

Catecholamines will act on the beta adrenergic receptors on the heart, which will increase the force of contraction, there will be an increase in stroke volume (slight) and it will increase heart rate (“+” chronotropic effect on the heart, increase in systolic BP). Arterioles on the systemic side: stimulate beta receptors in smooth muscle. Diastolic pressure is really due to the amount of blood in the arterial system, while you heart is filling with blood.

3. Arterioles: The gatekeeper of tissue perfusion

Who controls the amount of blood in arteriole system, while your heart is filling in diastole? Your peripheral resistance arterioles – that maintains your diastolic blood pressure. So, when they are constricted, very little blood is going to the tissues (bad news); good news: keep up  diastolic pressure – this is important b/c the coronary arteries fill in diastoles. This is all done with catecholamines.

4. Renin-Angiotensin System

Renin system is activated by catecholamines, too; angiotensin II can vasoconstrictor the peripheral arterioles (therefore it helps the catecholamines). AG II stimulates 18 hydroxylase, which converts corticosterone into aldosterone, and stimulates aldosterone release, which leads to reabsorption of salt and water to get cardiac output up. With decreased SV, renal blood flow to the kidney is decreased, and the RAA can be stimulated by this mechanism, too. Where exactly are the receptors for the  juxtaglomerlur apparatus? Afferent arteriole. There are sensors, which are modified smooth muscle cells that sense blood flow. ADH will be released from a nerve response, and pure water will increase but that does not help with increasing the cardiac output. Need salt to increase CO.

Example: bleeding to death and there is a loss of 3 L’s of fluid – how can you keep BP up?  Give normal saline is isotonic therefore the saline will stay in the ECF compartment. Normal saline is plasma without the  protein. Any time you have hypovolemic shock, give normal saline to increase BP b/c it stays in the ECF compartment. Cannot raise BP with ½ normal saline or 5% dextrose; have to give something that  resembles plasma and has the same tonicity of plasma. Normal saline is 0.9%. Peritubular capillary pressures: you reabsorb most of the sodium in the proximal tubule (60- 80%). Where is the rest absorbed?; in  the distal and collecting tubule by aldosterone. The Na is reabsorbed into the peritubular capillaries. Starling forces in the capillaries must be amenable to it. Two starling forces: oncotic pressure (keeps fluids in  the vessel) and hydrostatic (pushes fluids out of vessel).

Example: When renal blood flow is decreased (with a decreased SV and CO), what happens to the peritubular capillary hydrostatic pressure? It decreases. Therefore, the peritubular oncotic pressure is increasing (ie the force that keeps fluids in the vessel), and that is responsible for reabsorption of anything into the blood stream from the kidney. This is why PO (peritubular oncotic pressure) > PH (hydrostatic pressure of peritubular capillary), allows absorption of salt containing fluid back into blood stream into the kidney. Tonicity of fluid reabsorbing out of proximal tubule is isotonic (like giving normal saline). ADH is  reabsorbing isotonic salt solution, but not as much as the proximal tubule. ADH contributes pure water, therefore, with all this reabsorption you have an isotonic sol’n add the ADH effect and the pt becomes  slightly hyponatremic and hypotonic, therefore absorbs into the ECF compartment when there is a decreased CO.

Opposite Example: increased SV, and increase arterial volume, will lead to stretch of baroreceptors (innervated by 9th and 10th nerve), and a parasympathetic response will be elicited, instead of a sympathetic response. There will not be any venuloconstriction nor any increase in the force of contraction of the heart. This is fluid overload; therefore we need to get rid of all the volume. There is increased renal blood  flow, so the RAA will not be activated. Fluid overload does not ADH be released. The peritubular hydrostatic pressure is greater than the oncotic. Even of the pt absorbed salt, it wouldn’t go into the blood stream, and it would be pee’d out. Therefore pt is losing hypotonic salt solution with increased in arterial blood volume. Need to know what happens if there is decreased CO, what happens when ANP is released from the atria, and give off diuretic effect; it wants to get rid salt. ANP is only released in volume overloaded states.

Example: pt given 3% hypertonic saline: what will happen to osmolality? Increase. What will that do to serum ADH? Increase – increase of osmolality causes a release of ADH.

Example: What happens in a pt with SIADH? decreased plasma osmolality, high ADH levels.

Example: What happens in a pt with DI? no ADH, therefore, serum Na increases, and ADH is low How to tell total body Na in the pt: Two pics: – pt with dry tongue = there is a decrease in total body Na, and the pt with indentation of the skin, there is an increase in total body Na. Dehydration: Skin turgur is preformed by pinching the skin, and when the skin goes down, this tells you that total body Na is normal in interstial  space. Also look in mouth and at mucous membranes. If you have dependent pitting edema that means that there is an increase in total body Na.

SIADH – gaining pure water, total body sodium is normal, but serum Na is low; have to restrict water.

Right HF and dependent pitting edema – fluid kidney reabsorbs is hypotonic salt solution with a decreased CO (little more water than salt), therefore serum Na will low. Numerator is increased for total body sodium, but denominator has larger increase with water.

What is nonpharmalogical Rx of any edema states? (ie RHF/liver dz) – restrict salt and water What is the Rx for SIADH = restrict H2O. What is the Rx for any pitting edema state? Restrict salt and water. Pharmacological Rx for pitting water – diuretics (also get rid of some salt).

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Click here to view the embedded video.

Ever feel lost in the Pre-Med grind, not knowing what to do next?

Have specific questions about the medical education process and get mixed answers all over the web that leave you feeling more confused and alone?

Chances are one of the hundreds of people I’ve coached since 2004 have asked me the same questions!

This podcast explores my new website’s organization. It will be released soon, don’t worry - and you can join for only $12 ! (UPDATE: it’s released here –> Medical Support Community).

I took all of the how-to video tutorials, email questions and survey responses and organized them all into the 15 Sections below.

The only way to access this information is on the new site: http://medical-mastermind-community.com/podcast/speed-reading-for-medical-school

1 Getting Started

ARTICLES:
•    Overview of the medical education process
•    16 Step PreMed Guide
•    Daniel Williams’ story
•    Importance of journaling
•    SAMPLE interview journal
AUDIO:
•    The medical education process
•    What med school is really like

2 Premedical Decision Making

ARTICLES:
•    Admission requirements
•    Canadian med student career choices
•    Deciding on a career in medicine
•    ECFMG certification fact sheet
•    ECFMG information booklet
•    Four reasons to avoid medical school
•    Med school affects undergrad choices
•    Seven osteopathic competencies
•    UK med student career choices
•    US med student career choices
AUDIO:
•    Admission rates
•    Admission requirements
•    Deciding on a career in medicine
•    Four reasons to avoid medical school
•    Osteopathic medical training

3 Organizing Your Experiences

ARTICLES:
•    Address label templates
•    Checklist for getting organized
•    Email accounts
•    Legal documents
•    Master application binder
•    References
•    Transcript checklist
•    Transcript request template
•    Work history template

4 Building Character Into Physician Training

ARTICLES:
•    Arrogant doctors hurt patients
•    I DON’T KNOW – The three most important words in medical education
•    Six habits of highly respectful physicians
•    Words as scalpels
•    Ethics
•    Euthenasia
•    Human subjects research training
•    Medical futility
•    Neurenberg
•    Suicide
•    Ethics Movement
•    Tarasoff case
VIDEO:
•    Becoming the genuine article

5 Components of the Application

ARTICLES:
•    Academic honors
•    SAMPLE Application summary sheet
•    Certifications
•    Extracurricular activities
•    Letters of recommendation
•    Composing a letter of recommendation that captures the applicant as an individual
•    Dr Williams’ medical school application
•    Military experience
•    Research
•    Research commentary
•    Student organizations
•    Volunteer activities
AUDIO:
•    Letters of recommendation

6 Writing Your Memorable Application

ARTICLES:
•    Checklist for the personal essay
•    How to write personal essays
•    SAMPLE personal essay
•    Practice vision essay
•    SAMPLE research description
•    SAMPLE MD PhD interest letter
•    SAMPLE Secondary application questions
VIDEO:
•    Packaging your story
•    Essay tips

7 Choosing Your Top Medical Schools

ARTICLES:
•    100 years after the Flexner report
•    Admissions – insider report
•    Allopathic medical school – US and Canada
•    Caribbean medical schools
•    Feedback in clinical medical education
•    Hot topics in medical education
•    Impact of formal continuing medical education
•    Learner-centered approaches in medical education
•    Osteopathic medical schools
•    Systematic review of physician performance
•    Teaching evidence based medicine
AUDIO:
•    Osteopathic physicians – are they different?

8 Counting the Costs

ARTICLES:
•    Financial assistance checklist
•    Debt is not all created equal
•    Financial assistance
AUDIO:
•    Burnout interview question
•    Financial aid in medical school

9 Grades

ARTICLES:
•    AMCAS’ GPA calculation
•    GPA calculator
•    The perfect GPA
AUDIO:
•    The perfect GPA

10 Sizing up the Competition

ARTICLES:
•    50 listener questions – the power of exploiting your competition
•    Checklist for exploiting your competition
AUDIO:
•    50 frequently asked questions
VIDEO:
•    Survival strategies

11 How to Study

ARTICLES:
•    MCAT study method
•    MCAT – special report
•    Checklist for maximizing your study methodology
VIDEO:
•    Exam strategies Part A
•    Exam strategies Part B
•    Speed reading system
•    5 Step study method
AUDIO:
•    5 Step study method

12 Personalized Progress Feedback

VIDEO:
•    Custom progress feedback

13 After Your Medical School Application

ARTICLES:
•    Having a successful interview
•    Interview topics
•    SAMPLE UT Houston interview letter
•    Program results by specialty
VIDEO:
•    Residency considerations
•    Insider match application and ranking system
AUDIO:
•    Changes in the match system

14 Maintaining Your Edge

VIDEO:
•    Foxmarks Bookmarks tool for organization
•    iGoogle tutorial
•    Time management

15 Study Materials

MEDICAL SCHOOL:
•    Modern Medical Scrolls – 1275 pages of medical student notes
VIDEO:
•    Study Notes Video
Medical College Admissions Test:
•    14 Biochemistry documents
•    1 Evolutionary document
•    15 General Chemistry documents
•    8 Pathophysiology documents
•    4 Physics documents
United States Medical Licensing Examination
•    Bonus USMLE document

Reference:
Must have a free account with Academic Medicine, the journal of the AAMC, to view: http://journals.lww.com/academicmedicine/Fulltext/2001/10000/America_s_Best_Medical_Schools__A_Critique_of_the.5.aspx

SEE THE FULL REPORT HERE: Evolution of a Physician In Training: Effects of the medical education pipeline on personal and professional development.

Daniel M. Williams, MD

The 5 phases of a physician in training are general categories that describe the professional and psychological changes that students can expect to face. These have been organized into a Medical School Mindmap full of 179 peer-reviewed, scientific articles that describe the processes necessary to become the consumate physician.
The Phases are as follows:

1. Standing At The Precipice: The Premed Syndrome
2. Adaptation
3. Assimilation
4. The Let-Down
5. Reemergence

This area of research is meant to provide the foundation for a Health and Wellness Initiative among physicians. Physician Health is a top priority with Dr. Daniel Williams and each area is broken down inside the Medical Mastermind Community that has grown up around this ideal.

Here is an excerpt from the original draft:

Phase 1: Standing at the Precipice

Premedical students engaged in the early medical education pipeline frequently share similar goals and ambitions. The most commonly described premedical student traits are hard working, competitive, motivated, goal-oriented, altruism, and prestige-seeking (22-24). Fairly early in their premedical experience they begin to learn of the imperfection in the system.

A number of frustrations faced by these bright, enthusiastic students begin before even entering medical school. The challenges face by these future physicians can be categorized as follows:

1. Selection Bias. Learning that affirmative action exists without understanding the need for diversity can be a shock (143,145,156).
2. Academic Preparation. Realizing their undergraduate premedical and M.C.A.T. preparation may not actually predict how competent they will be as physicians can be disheartening (46,45,48).
3. Premedical Advising. Many students encounter premedical advisers, though wonderful guidance has been published for decades (11,15,17).
4. Admissions Criteria. The paradigm shift being birthed in premedical curriculum, which seeks to broaden one’s humanities background and foster empathetic relationships, is taking a surprisingly long time (4,6,27,28,30,31). The transition period as more medical schools are changing their admissions criteria and interview process can leave the premedical student confused about what is important in their preparation (184).

Because these sytstem-wide messages that contradict their altruistic nature, it is not surprising that the majority of students matriculating into medical school already have a well established ethical framework that is difficult to mold (26).

Further, two of the most historically trusted sources of information flat fail the premedical student attempting to learn about medical education. First, institutions of higher learning remain hyper-focused on grade point average though is associated with mere surface learning in medical school and the “MCAT Myth” of requisite rote memorization had been debunked by the mathematical application of Bloom’s Taxonomy (46). Second, nationally syndicated journalists yield influence in the ranking of “top medical schools”, but their method are ill-conceived; are unscientific; are conducted poorly; ignore the value of school accreditation; judge medical school quality from a narrow, elitist perspective; do not consider social and professional outcomes in program quality calculations; and fail to meet basic standards of journalistic ethics (32).

Sadly, the more idealistic and altruistic the nature of the unsuspecting premedical student, the greater the expectations in their career, and the greater the disappointment that comes in later phases in their evolution.

If we can be of any specific help to you, please feel free to contact us through the Ask A Doctor page.

Ping my blog

Because no two people read the same MCAT passage exactly the same, it’s important to harness your internal dialogue to interpret passages, stay calm, and score higher - all at the same time. To learn more, visit www.testprepny.com.

There are only a few more episodes of expert interviews that will appear on this site. The continuation will be on www.Medical-Mastermind-Community.com

To get more Test Anxiety training and management instruction, join the CD of the Month Club, which also included Medical Mastermind Teleconferences with Doctor Dan.

Enjoy,

Dr. Dan

Dr. Ferdinand’s tells us about his not-so-secret performance on the MCAT and about his fatal error during planning his MCAT that caused him to not be able to even take the exam!

Listen to ALL of the expert interviews on the Medical School Podcast.

[More...]

The Association of American Medical Colleges administers the MCAT, accredits allopathic medical schools in the U.S., and manages the medical school application service.

The trend over the past 2 decades has been to emphasize thinking, organizing information, and problem solving rather than rote memorization.

In this episode, we two physicians discuss exactly why that is, what you can do to prepare, and ultimately whom you can trust when it comes to such an important exam – yourself!

Future episodes will cover

* Dr. Ferdinand’s 6 Steps to MCAT Preparation, which is remarkably similar to my 5-Step study method.

* Dr. Ferdinant’s interview with the “Father of MCAT Books” (Dr. Flowers)

* How a mastermind community can help premeds AND medical students

Listen in to learn more…

In this interview with Randy Freeman, a Premedical University DVD Home Study Course graduate, we delve into 4 major areas:

1. How to get the “I’m GOING TO be a doctor” mentality
2. Levels of Pre-Med sophistication and commitment
3. Can you change your priorities later down the road, as a physician?
4. Premedical Solutions that work - study for the MCAT while in undergrad!

The American Medical Student Association will again promote my next live, 2-day conference on July 18-19, 2009. Several things will happen at this Medical School LIFE Conference:

• The new Medical Mastermind Community site is now launched and explained in this podcast!
• 102,000+ Medical Students and Pre-Med Students are invited to watch the conference via live-streaming or phone in

Finally 3 major topics will be covered at this Burnout Prevention seminar:

1. How To Survive And Thrive In Medical School
2. Advanced Pre-Med Seminar
3. Single Payer Solution For Health Care Reform.

Registration includes the Pre-Med DVD Home Study course and residency/med school application homework is required prior to the conference date in order to maximize you individualized coaching sessions.

This conference is sure to be hoot!

Thanks for your support,

Doctor Dan

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Announcements: * CD of the Month Club is now in it’s 21st month. The infrastructure for mass production is now in place.

Check out the new MCAT podcast interviews with GOLD STANDARD MCAT author, Dr. Brett Ferdinand

The Medical Mastermind Community is now live! Call me on our next pre-med conference call!

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A future doctor recently told me she made a 16% on a full-length Kaplan Practice MCAT. While that sounds bad, let’s put that score into perspective and look at how overall core knowledge deepens - specifically, how that is reflected in practice test scores. We’ll also delve into how to predict what score you’ll make on the actual MCAT.

This was my answer: “I sincerely understand your frustration and experienced it myself after taking the Kaplan course and my grades averaged out to be the same, having taken the MCAT 3 times. As a premed adviser now, I get this question a lot. You are not alone.” You have a multi-part topic, so let me take each item in turn: 1. What do people actually make on the MCAT? What is the MCAT cut-off?

Please give me real numbers! It’s on a bell curve so if you’ve taken statistics you know that they can separate out the elite by keeping people away from the 100% correct end of the spectrum. In fact, 60% raw correct answers can actually be solid and each test is weighted differently. See, each test is drawn from a bank and each question is weighted for it’s own usefulness.

There are a significant amount of test questions that are being assessed as keepers, but are not part of your grading. Here is where you can find the most recent REAL MD MCAT scores in Texas, Osteopathic MCAT Scores, and AMCAS MCAT Scores.

2. Do practice MCAT tests commonly show low scores? [Better yet, do these low practice scores really reflect how well I'll do on the real MCAT?] ANSWER: A full-length practice MCAT form a reputable source, such as Kaplan, AAMC, or Princeton review are reasonable reflections of how well you’ll do on the real thing. How to interpret your performance on these tests is actually more useful in real life. As a rule of thumb, scoring between 60-70% is actually average and approaching a solid score. Let me be clear, I’m not talking about little quizzes because the sample size of questions does not give you an accurate representation of your body of knowledge. Only pay attention to full-length, timed tests. I recommend you do between 3-7 of them, until you consistently get your overall average over 60% correct. If you expect to ace the MCAT you’ll want closer to an 80% average.

3. Is there another way to prepare for the MCAT? ANSWER: The best way I teach people to prepare for the MCAT is to start learning the material from the first day in undergraduate, if possible. Buy a respected review book and take notes in it while in undergrad and taking those classes. Write down revelations and pearls of wisdom as you begin to get insight into the different prerequisite disciplines - keep the book near you and review it periodically. Too many people only “review” for the MCAT, which often means RELEARNING material form 1.5 years ago or more and this is a tremendous waste of brainpower, not to mention the added stress has been shown to decrease long-term memory (cited resource is a meta-analysis). *******************************************************

Residency Spotlight: Surgery After 4 years of medical school, General Surgery takes 5 years. Many people sub-specialize after that and go to fellowships. Fellowships may be in GI Surgery, Pediatric Surgery, Trauma, or transplant. There are some training programs that are surgical which do not require a General Surgery residency first: Urology, Ob/Gyn, and Neurosurgery. Cheers, Doctor Dan

Hi!

I hope you enjoy the fact that I’m switching to video. You can still just listen on your iPod if you prefer, but I’ll be showing you tons of on-screen tutorials. You can see the video version by looking in the Video Podcasts section of your iPod directory (scroll through the videos…).

The MCAT questions, DVD course and FREE E-book are now available through the Medical Mastermind Community only. Ive launched a community website for all the fans that have built up around this movement in the past 2 years!

Cheers,

Dr Dan

• All 200 of the peer-reviewed, scientific journal articles were posted inside the web site for members only. They outline every facet of the medical education journey and correspond to the 5 Phases in the Evolution of a Physician in Training, which is my Physician Wellness Initiative. The idea is to increase awareness, receive validation, and try suggestions from others to find relief. So, just read the articles as you face the different ups and downs along the way.

• All of the medical school exams were also uploaded to the website. Previously they were only available as part of the CD of the Month Club, but we found it was inconvenient not knowing which tests covered specific material. The web outline breaks down each block exam by the topics covered on each set of tests. You can check out the navigation without logging in.

• Facebook 30-day challenge. If you’ll make a video about the Medical School Podcast or Speed Reading for Medical School course, I’ll give you a free, 30-day account tot he Medical Mastermind Community online - a $27.99 value. This includes our biweekly conference calls, from which video archives are now all updated.

Call me, Doctor Dan, in one of our Medical Mastermind Support Groups and discover how to stay true to yourself during rigors of the medical education marathon.

Check the Medical Mastermind Group Schedule and login information. Hope to talk to you on the next call.

The “medical education process” covers the whole gamut from thinking about becoming a doctor, through the prerequisites, MCAT, and application, and never really ends in residency, fellowship and with continuing medical education as a practicing physician.

Do you have what it takes to be a lifelong learner?

Better yet, how many people really encourage you to follow that dream? My guess is that you’re like the hundreds of students I have coached, and that you’ve had some degree of discouragement along the way.

While there are many reasons for this, the only thing that matters to the motivated pre-med and medical student is getting through it - sanely!

Well, that my friend is exactly what the Medical Mastermind Community is all about. This video describes a hint of what the upcoming community is all about. If you want to learn more, sign up at MedicalMastery.com on the Early Notification List and be included.

In the meantime, seek out existing pre-med clubs, medical student organizations, Healer’s Art courses or hospital volunteer offices for support. If someone brings you down, stresses you out, or discourages you from accomplishing your dreams - get away from them!

Yes, this may mean friends and family. They’ll come around later when you’re successful, believe me. You need new friends. Just like the saying “you are what you eat”, you think like those with which you spend your time.

Hope this was an encouragement and sparks some self-care interest. The medical education process is a substantial percentage of your adult life - don’t forget to live!

Doctor Dan

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The medical school application is only one phase of your life. In this podcast and blog, I put this event in to the context of the entire medical school application process, give you some things to look forward to and prepare for, as well as direct you to where you can find an entire archive of tips like these all in one place.

By the time you submit your medical school application, you deserve a pat on the back. After all, you’ve completed the MCAT (in most cases), most of the medical school prerequisites and college, and overcome a large part of the mind game - talking yourself out of it. Many people change their mind and a growing trend is for ill informed pre-health advisers, with no qualification to speak on the subject, to discourage attending medical school.

From the time you submit your medical school application to the time you start your first day of medical school, there are a lot of activities that take place.

Interviews, ranking programs for the electronic match, match day, welcome parties, moving, and shopping. Oh yea, and preparing those closest to you that you’re about the be besieged by books and to prepare for some distance. Let’s take each of these in turn…

Getting an interview is often the hardest part to getting into medical school. More specifically, getting an adequate number of interviews. How many medical school interviews is enough? Most people feel ten is a good number. Why so many? Because they interview 7-10 times more students than they have seats for.

After you complete all of your interviews, you log in to the online ranking and matching service and rank the programs in order of your preference (only the ones you interviewed at). If there’s a school you don’t want to go to under any circumstances, you don’t have to rank it in your list even if you interviewed there. An important step is to “certify your rank order list”. You can rearrange the list as you decide for weeks, but once you certify it there’s no turning back. (I certified mine the day before.) If you don’t certify you’re not in the match, so don’t wait too long.

I made a video tutorial on the match application and ranking system. It’s the only behind-the-scenes look available and I’ll tell you how to get your hands on it at the end of this podcast.

In November of 2008, I released Episode 9 and we discussed drastic changes in the match system, primarily those in the Texas system. You can visit that episode in iTunes or MedicalMastery.com.

Match day will be memorable no matter what happens. At a certain day and time, usually around February or March, thousands log in to the online ranking service to find out if they’ve matched and where.

The match also occurs in the 4th year of med school and is very similar, but I thought I’d discuss the differences here.

This is really similar to a 3-day process, so let’s take the events in order:

Day 1: Login to see if you matched or not. It tells you YES or NO, not where you matched.

Day 2: Those that didn’t match are able to view a list of all programs that have unfilled residency positions. Your medical school usually helps you find a program somewhere during a 48 hour period known as

the scramble.

Day 3: Two days later you meet at your school and usually have some sort of ceremony to find out where you matched.

Included in my archives are a Video on residency considerations and an article on program results by specialty.

Many medical schools have some sort of Welcome Weekend, or event before medical school that allows you to meet people, loosen up, and get psyched for medical school. In my school we did this the weekend right before it started. This is a very fun time and where you’ll meet many lifelong friends.

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Big Question: What is your medical school entrance party or interview story?  Comment below…
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QUICK TIP: All of the videos, interviews, and articles will soon be released to the public. Sign up for the early notification list at www.PremedicalUniversity.com. You’ll also get the 7-day PreMed email course when you sign up for free. You can unsubscribe any time.
QUICK REFERENCE:
American Medical College Application Service: http://www.aamc.org/students/amcas/start.htm
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Mission Statement
“Medical Mastery seeks to podcast meaning into medical education by combining faith, high-quality lectures, and charity.”

Announcements:
Dropping a hint about my big project…got a high speed internet connection?

Also, for simplicity all CD’s will be mailed out during the last week of the month.

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Podcast topic

“If you had it to do all over again, what would you do different?”

This is a question I get a lot, in different forms. In fact my new big project I’m coming out with in the next few months is exactly geared toward answering this question - in all it’s detail.

See, feedback from my podcasting has made me realize that my experience with the premed obstacles you face is fodder for you cannon! I get just as excited with you as I coach students and reawaken their dreams of becoming a physician.

The biggest tips I can think of to answer this question with brevity are the following:

1. As an undergrad, write out what my life’s priorities are. Establish from the beginning and keep the document handy for editing as time passes.

2. Identify what you are and are NOT willing to sacrifice in persuit of your goals. The “I’ll do anything” mentality won’t be reliable forever.

3. The first year of medical school and then test weeks will clearly have to be priority during medical school. It’s four years, but many students schedule easier months during the last year.

4. Much further down the road, do the same thing when considering which residency specialty interests you. Many people change their minds about this over time so stay flexible as you learn new information.

5. Keep your “Life Priorities List” handy as you investigate your career options. Note: you really don’t have to do this until the end of the third year of medical school, when you schedule your electives for the fourth year.

Biggest tips for residency:

1. Choose something you are passionate about.

2. If possible, don’t make any BIG life changes. Of course, who can really plan these things? There’s never a “perfect” time to have a family..

3. Outline reservations you’ll have - that is, things you WON’T compromise clearly identified at the outset. As you progress through residency, which can be all-consuming, an indicator that you may need a career change is when you find yourself compromising your life’s priorities.

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QUICK TIP: Sign up for the next Live Premed Advising Webinar when you enroll for the 7-day email course. Limited number of people available for the Tele-Clinic and I may offer this to you for a short while.

QUICK REFERENCE: http://premedicaluniversity.com

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Charity of the Month for March 2009: Habitat for Humanity will receive all donations made in the upper left hand corner of www.MedicalMastery.com.

Charity Mission Statement: Decent Housing For All

“Through the work of Habitat, thousands of low-income families have found new hope in the form of affordable housing. Churches, community groups and others have joined together to successfully tackle a significant social problem – decent housing for all.

Today, Habitat for Humanity has built more than 300,000 houses, sheltering more than 1.5 million people in more than 3,000 communities worldwide.”

“Since its founding in 1976 by Millard and Linda Fuller, Habitat for Humanity International has built and rehabilitated more than 300,000 houses with partner families, helping house more than 1.5 million people and becoming a true world leader in addressing the issues of poverty housing.”

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Mission Statement:
“Medical Mastery seeks to podcast meaning into medical education by combining faith, high-quality lectures, and charity.”

Episode 12: Ostopathic Medicine Training: What’s so special about it?

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There is more than one way to become a physician: Allopathic and Osteopathic. Today’s discussion is about the pathway to doctor of osteopathic medicine (D.O.)

In addition to all of the traditional aspects of physician work that you’re familiar with, osteopathic physicians theoretically have a few other tenants that they emphasize:

1. The human body systems need to be in correct relationship with one another (really just normal physiology)

2. The musculoskeletal system gets some special attention.

I’d like to add a third: the osteopathic physician is taught to take care of the “whole patient”. Holistic medicine refers to the taking care of the whole person, i.e., mental, physical, emotional, and spiritual health.

Really the only difference is that they can pop your back! They get all the same jobs, direct hospital departments, and go to all the same residency programs.

So, why are we talking about them? Because some people don’t apply to these programs as a first choice, leaving opportunities on the table for you.

In 2007, the average allopathic applicant had a MCAT score of 28 and a GPA of 3.5. An average osteopathic applicant had a MCAT of 25 and a GPA of 3.5.

Many residency programs accept the COMLEX exam, but some may also require the USMLE.

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MEDICAL SPECIALTY SPOTLIGHT: Infectious Disease

4 years of medical school
3 years of internal medicine residency
2-3 years of fellowship training in Infectious Disease

Traditionally, Infectious Disease specialists operate as a consult service in the hospital. The main activity is in clinics.

The approach is not that the ID doctor is there when someone has an infection, but they are there to help when the treating physician confronts a complicated patient outside his or her expertise.

They also hold the purse strings for the hospital’s pharmacy by serving on committees that decide which drugs can be dispensed and which ones the hospital will and will not provide. The newer, expensive antibiotics often need special approval from the committee on an individual basis. They’re not being mean, their slowing down the evolutionary resistance mechanisms of the microorganisms trying to kill our patients.

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QUICK TIP:

Apply to them first so that you don’t forget to do it. Remember, there is nothing second rate about being a D.O.

QUICK REFERENCE:

National Board of Osteopathic Medical Examiners

http://www.nbome.org/

List of Osteopathic Medical Colleges:

http://www.nbome.org/colleges-list.asp

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Announcements:
Happy New Year!
It’s now been 9 months of podcasting and we have over 21,178 downloads. I’m very encouraged by your emails and support.

In that short amount of time, hundreds of your questions have been answered and organized into a mindmap. With your help we put together a comprehensive, individualized PreMed coaching program. Visit www.PremedicalUniversity.com for more information.

The PreMed CD of the month club now has a link on the right of MedicalMastery. There is room for 11 more people right now. First come, first serve. That link will only be available intermittently when seats are available.

Live Teleclinics now available. Sign up for the free PreMed eBook on MedicalMastery.com and you’ll also get email notification of upcoming teleclinics.

Submit topics in the online survey “Grill the Guru”. The Ebooks is 16 chapters emailed to you weekly with other, exclusive PreMed strategies and insider

advice also. In total, you’ll get over 3 months of PreMed email content that you can save, store, and search in your email service for years to come!

DON’T DELETE the emails.

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Podcast topic

The first teleclinic we did had a nice video slide that covered all the steps in the medical education process. The new website that will host the free teleclinics.

After you’ve mapped out when you’ll be finished with college and all of the prerequisites for medical school, the next available August would be your first potential entering month and year. Plan to take the Medical College Admissions Test the year before.

You can successfully back-schedule from this date all of the necessary preparations so that you have time to do everything you need.

The first year of medical school is perhaps the hardest of all. You will be forced to adopt different learning styles for different types of information on the fly. The focus is on how the body works normally.

FIRST YEAR CLASSES:
Biochemistry
Cell development and tissue biology
Community health
Epidemiology / biostatistics
Family medicine
Gross anatomy
Growth and development
Health care policy
Hematology
Histology
History of medicine
Immunology
Interviewing
Introduction to clinical skills
Medical ethics
Molecular biology
Physiology
Preclinical electives
Problem-based learning

The second year is when you learn what goes wrong with human physiology.

SECOND YEAR CLASSES:
Addiction medicine
General pathology

Infectious disease
Introduction to clinical medicine
Microbiology
Psychopathology
Psychiatry
Nutrition
Neuroscience
Pathophysiology
Pharmacology
Preclinical electives
Problem-based learning
Systemic pathology

At the end of the second year, you take the United States Medical Licensing Exam, Step 1. This is the weightiest of the 4 USMLE exams as it affects which residency specialty you get into.

The third year starts 2 years of clinical rotations. Often one month long, you spend time doing many of the specialties.

THIRD YEAR ROTATIONS:
Surgery
Internal medicine
Pediatrics
Obstetrics and gynecology
Psychiatry
Primary Care

The USMLE Step 2 Clinical Knowledge is taken before the end of medical school, as well as Step 3 Clinical Skills. The former is a computerized exam, the latter is an in-person, all day patient care simulation.

The fourth year is the most relaxed of all. By this time, you already have the letters of recommendations you need for residency application and the 4th year elective grades don’t matter as much as the USMLE Step 1 and basic science years’ grades. Application for residency begins this year so some people have trouble choosing a specialty at this point because there isn’t much time between 3rd year and application time.

Internship is the same thing as the first year as residency. Depending on the residency tract, some people do take a separate intern or transitional year and then begin their second year of postdoctoral training.

After the first year of residency training, you are eligible to take the USMLE Step 3 - the last of them! My, what a good feeling it is to be done with them!!

The major goal comes after residency when you take your board specialization exam.

Fill out the Grill the Guru survey on medicalmastery.com to let me know if you are interested in a Medical Specialty Spotlight as an addition to future podcasts. I need 30 responses to proceed with that decision.

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QUICK TIP:

Map out the rest of your college classes needed for both graduation and medical school prerequisites. Use a physical calendar, printed out for the next couple of years if needed. Write on it by semester, journal on it, and check off your classes as you complete them.

This will help you even if you already know it by heart.

Be sure you have a signed degree plan by your department chair so there are no surprises when you’re ready to graduate.

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QUICK REFERENCE: CDC Internship Opportunities

http://cdc.gov/education/

Click on the College Student links for more information.

AMSA PreMed: Definitely check out the listserve option. You must be a member, though. Membership starts at $35.

http://amsa.org/premed/

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Charity of the Month for January 2009: Innerchange Freedom Initiative http://www.ifiprison.org/

The InnerChange Freedom Initiative (IFI) is a proven, voluntary and holistic values-based Reentry Program. It seeks the development of the whole person – spiritually, intellectually, emotionally, and physically. The spiritual formation aspect of the program is based on the life and teaching of Jesus Christ.

Charity Mission Statement:
This mission of IFI is to create and maintain an environment where change may take place and to foster respect for law and the rights of others.

Testimonial

“I had the chance to be mentored by people who really cared about me—Christian men who are a good example of how to treat their family and loved ones,” he describes. “I now have a desire to put other people first.”

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Mission Statement
“Medical Mastery seeks to podcast meaning into medical education by combining faith, high-quality lectures, and charity.”

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This is Part 2 of a telephone interview with Celeste Whisenant, a second year medical student.

She answers all the tough questions about what each year of medical school is like (at least year 1 & 2 that she knows about) and compares them to TV shows in some surprising ways.

This interview is part of the Grill the Guru series, in which I ask questions directly from the survey on medicalmastery.com.

Here is the rough outline of the questions I put together for this interview:

***Tell us about your self. “What school are you attending? How did you decide to attend that school over the other schools at which you were accepted?”

(we’ll have to explain the rank here)

***“What is med school really like? (as an ms1, ms2 etc.)” “What is the daily workload like? How much sleep do you get?”

***Is med school similar to what is shown on TV shows? (humor, the dating, drama, characters, hours, stress, family/home life)

***What do you know about D.O. schools, if anything?

Enjoy and email me if you have any questions!

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Mission Statement
“Medical Mastery seeks to podcast meaning into medical education by combining faith, high-quality lectures, and charity.”

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Topics in this podcast:

Announcements

Introduction of Celeste Whisenant - covered in the audio only

The Dreaded Interviewer - covered in the audio only

Current Strategy for the Medical School Match (Sign up for the Free eBook in the upper right and you will get access to photos of the ranking system online and learn exactly how to avoid the problem Celeste had.)

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Announcements:

The CD of the Month Club now off the market.

Live Webinar: get all your questions answered in one place - for FREE!
December 2, 2008 at 6PM Central time. Sign up for the Free PreMed eBook on
www.MedicalMastery.com and you’ll get an email with login instructions in the
days leading up to the seminar.

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Current Strategy For The Medical School Match:

In 2007, a major change occurred in the way Texas medical schools choose their students, more in line with what’s been done in the rest of the country. Prior to this change, students applied to the recommended 20-30 medical schools and waited for an interview. After interviewing at hopefully several places, students ranked their favorite schools (only those they interviewed at) electronically on a secure website.

Then, the student just waited for “match” day in early February.

Well, the game has changed and I want to give you some strategic tips on you should approach this for your best advantage. You still apply to the 20-30 schools and need to get an interview, which I have always felt is the biggest cut-off in the process. However, now it really has become a race to get absolutely the earliest interviews possible, especially if you really have a favorite medical school you want.

See, once the medical schools have met you at the interview they can send you an “Early Offer” giving you 2 weeks to go ahead and accept a position at that school. These offers are independent of any other interviews you may have scheduled.

For example, if you have an interview in October (one of the very first of the season) and the rest of yours are in December, the first school could send you an Early Offer. You have 2 weeks to accept it - before you’ve even interviewed at the other schools! If you say no and want to interview at the other schools, then that first school will include you in the electronic match (discussed in my Free eBook -sign up in the upper right).

The strategy I want you to realize is that as soon as interviews start in October, seats are filling up all over the country. Students are grabbing up the first opportunity to secure a position.

You should too.

Do absolutely EVERYTHING possible to go to the earliest interview date offered to you.

My recommendation is that the majority of applicants should accept the first offer they are given. The electronic match is now for the leftovers, those people that didn’t get any offers or refused them. The ones that refused offers are either completely stellar students that had other offers on the table or didn’t listen to this podcast.

Don’t decline your last Early Offer.

Take what you can get. You’ll thank me later.

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QUICK TIP:
So, what can you do about these changes? Here’s a checklist for you to follow:

__ Ask for letters of recommendation by February or March at the latest.

__ Submit your application to medical school during the FIRST WEEK they start accepting them.

__ Fill out and mail or electronically submit all secondary applications to medical schools that require them. (Check each medical school’s admissions website to download or read about secondary applications they may require. If there is any doubt, pick up the phone and call them! Are you beginning to fell my emphasis about how proactive you NEED to be?)

__ As soon as your application is submitted, check the website every day to make sure the medical schools have downloaded your application materials.

__ Finally - and MOST IMPORTANTLY, call each medical school you applied to. Tell them “Hi I wanted to make sure my application is complete and if there’s anything else I can provide because I am really interested in your school.”

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QUICK REFERENCE:
Are medical students meeting their best possible match? (2003 data)
http://www.siam.org/pdf/news/305.pdf

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Mission Statement
“Medical Mastery seeks to podcast meaning into medical education by combining faith, high-quality lectures, and charity.”

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ANNOUNCEMENT:

I’m almost finished with my complete, A-Z, PreMedical video tutorial course! If you’re not already one of the hundreds in the exclusive email list receiving chapters of my FREE PreMed eBook, sign up in the upper right of medicalmastery.com now. Very soon, only people who have signed up will get the details on this video course!

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This episode is the first in an interview series that was suggested by you - our listeners! Use the Grill The Guru survey on medicalmastery.com to submit your questions for future medical students and doctors I will interview.

Now, we’ll get right to the interview with Tyler Relph - a former PreMed tells us why he changed his mind. To hear the rest of this interview, join the CD Club online today!

Here is what he wrote and what we used as the outline for the interview. That is, until he turned the table at the end…

“I grew up playing soccer competitively, so the sports emphasis has always drawn me. When I was considering medical school, I was planning on going into orthopedic surgery followed up with a sports medicine fellowship. I wasn’t too concerned with the schooling I would go through, however the thing that made me call of my medical degree pursuit was the lengthy residency in conjunction with the 80 hour work week.

1. FAMILY - I’m married and have three children (3, 2, and a NB) If I were to go through medical school, I wouldn’t be an MD for 6-7 years (one year to finish up my bachelors, one year to finish up my prerequisites/ apply for med school, and four years of medical school). At that point my children will be 9, 8 and 6…then I start into my 80 hour work week as I venture into 3-7 years of residency (surgical specialty of some sort). Therefore, I wouldn’t be starting my practice until my oldest is 16. Through this possibly 13 year schooling journey, I believe I would miss out on my children’s lives too much to the point that it would affect them in a negative manner. I also have to consider time to continue to build into my marriage - to achieve my educational goals at the cost of my family is no success at all!

2. PAST EXPERIENCE - I have benefited from chiropractors immensely as I previously twisted my sacrum bad enough that I could barely walk. After seeing a chiropractor for about a year, I was able to join the military (i.e. all of the physical demands put on the body through physical fitness) and have no problems with my sacrum.

3. LIFESTYLE - Once again…it all boils down to family. I want to be able to be at home every night to ask the kids how their days were without the interruption of having to be called in. I can set my own hours - providing a two hour lunch break to be able to eat lunch with my wife and continue to build up that relationship. The money has very promising rewards - you work hard, the money will follow. Being my own boss and, if in a team practice, making the decisions with my fellow practicing chiropractors is “complete” freedom.

4. DURATION - The number of years of training - this brings me back to point one. By the time I am done with chiropractic school (with no residency of 80 hours a week), I will be thirty, at which point my oldest will be 8. This allows me to be entering into my practice when the children are still young, being able to nurture those relationships as the teen years begin to approach.

I will be attending Palmer West where a sports emphasis is available, in which students get to practice on professional athletes (currently the sports council is attending the Ironman competitions in Kona, HI providing chiropractic assistance to the competitors). Through this training, I will have the opportunities to work with professional athletes ensuring a healthy structural alignment to aid in the continuance of their careers.

Respectfully,
Tyler Relph”

I hope this interview helped you guys out. Visit medicalmastery.com and click on the survey on the right called Grill The Guru to get your questions answered.

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QUICK REFERENCE: links to tissue research foundation and other job-related PreMed activities can be found on Google.

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Mission Statement
“Medical Mastery seeks to podcast meaning into medical education by combining faith, high-quality lectures, and charity.”

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In this episode:

ANNOUNCEMENTS
PODCAST UPDATE
Pre-Med E-book now a 17-week FREE course
$0.01 Pre-Med CD lays the groundwork for EVERYTHING Pre-Med!
LISTENER REQUESTS
Q & A

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ANNOUNCEMENTS:

LEVEL 1: PODCASTS: I’ve had a slow pace with podcasts lately due to the pressure
of keeping up with residency. The newsletter has been reorganized to provide
continual email updates every 4 days, however.

LEVEL 2: NEWSLETTER: The FREE Pre-Med E-book had a fatal flaw. The newsletter
was cutting off the 50+ page Diary of a PreMed Student book around page 10 or
so. Thank you Mr. C. from Detroit, Michigan for pointing that out! There are
many other topics that get emailed to you in addition to the E-Book contents,
but it has been repaired to send you one of the chapters per week for a 17-week
course – all FREE!

LEVEL 3: CD OF THE MONTH CLUB: The MINDMAP is progressing nicely. This tool
organizes all of my Pre-Med content, and MANY topics not in the podcasts, using
an outline formatting software. For the first time you can have all of the
medical education websites, files, videos and podcasts all in one place! This is
only available through the CD of the Month Club. Sign up for my FREE Pre-Med
E-book at www.MedicalMastery.com using the attached file you get in my emails.

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LISTENER REQUESTS:

The survey on medicalmastery.com has sparked many questions, comments, and
suggestions for how to improve this Podcast. The most common request was for
more podcasts at more frequent intervals. Believe me, I’m doing the best I can
as a medical resident. I really enjoy helping Pre-Med students. It’s a passion
of mine and I look forward to staying involved with you guys in the future.

This podcast emphasizes the importance of asking your questions! NO question is
to simple. The only “dumb” question is the one you don’t ask. As you can see
there are all different levels of experience of the Pre-Meds that listen and
there is something here for everyone. Also, by asking your questions you are
helping each other out because you’re not the only one that wants to know. We’re
going to go through over 50 questions.

I am accepting introduction music submissions for an honorable mention. The
music has to be original, so if there are any musicians out there you are
invited to submit short music segments for introduction, special announcement,
and closing segments.

Listeners have also requested that I interview medical students and doctors.
Please submit questions for each. I want to make sure I ask them the things that
YOU most want to know.

If you have any other suggestions, visit medicalmastery.com and complete the
survey. Be sure to sign up for the FREE Pre-Med E-Book Newsletter.

====================================================

LISTENER Q & A’S

QUESTION 1: There were four similar questions –

Part A:

I am currently doing all basic classes including the basic sciences and my
intended major is Biology/premed and according to the UH NSM requirement I also
have to take a NSM capstone (which is either a double major, a minor, a thesis
or some research). But, after browsing the school website they have another
major that is interesting as well, its called B.S in Biology (medical
Technology) and it seems really interesting and the requirement are same except
their is a few more classes of chem but less math (all you have to do is cal 1)
but the last 30 hours are clinical programs. It sounds really interesting but
she told me that a lot of students that want to go into medicine do not take
this major! Is there a reason behind this? and plus do you think its a good
program? It also says that entry into a medical technology clinical program is
competitive, not a certainty. Although a minimum GPA average of 2.5 or better is
required by most medical technology schools. So, please let me know what you
think of this and let me know!!

ANSWER 1A

Congratulations on finishing another semester. By the way, I’m about to do
my next podcast that will answer your previous questions about which classes
to take and which schools to attend. The short answer is - choose your own
life! More to follow…

This is a very interesting question about the med tech curriculum. I say
that because it brings up a big concept in the admissions culture - program
hopping! See, this same question pops up when people transfer from Ph.D,
masters, nursing, or physician assistant programs and attempt to enter
medical school. The main question you have to answer is “why?”

What most advisors don’t demonstrate at the undergraduate level is a genuine
understanding of the CRITICAL health care provider shortage. If someone
takes up a seat in a competitive medical technology program and then doesn’t
fill that position in the community, but they change careers, per se, and go
into medicine, then they’ve wasted community resources.

Keep in mind, too, that state-supported schools (like UT and U of H) are
under a mandate to fill the shortage as efficiently as possible, or face the
threat of losing funding.

BUT HAVE NO FEAR

With the little bit I know about you, I already can see a bullet-proof plan
that will cement your entire application and undergraduate experience (at
least on paper). Are you ready?
1. Do whatever is safest and most convenient for you this summer.
2. Stick with whatever undergraduate major YOU like the most. Do the med
tech program if it sounds interesting enough to finish.
3. In your personal essay, state that you have an interest in pathology and
that is why you chose that major. You’re not lying, after all. Plus, if you
change your mind later, it’s a great career.
4. When your grades gain steady improvement, site that semester as the time
in your life when you decided to pursue medicine in all seriousness.
5. When you come back from India, step up your academic game and treat it
like a job.
You can do it.

Part B, C:

Transformation from RN to MD and the reality of it. Please
include experiences from medical school students. What do medical schools think
about nursing majors who are going into medical school?

Part D:

I want to learn about the MCAT prep and advice on choosing
a major for a BA or BS degree.

QUESTION 2

I was wondering if you had any references for me in order
to beef up my knowledge of healthcare policy and issues in the US (and maybe
abroad)? I would really appreciate any sources, or if you could point me in the
right direction.

ANSWER 2

What are you most interested in learning about? Just basic stuff to be
knowledgeable for interviews or something more serious for career aspirations?

My first thought is to subscribe to newsletters/magazines such as American
Medical News (by the AMA). I get this and that’s what they’re all about. They
represent 25% of US physicians and they’re all about policy.

QUESTIONS 3-49: From The Online Survey

The $0.01 first CD contains the answers to the following
questions:

• Video Tutorial: Getting Organized lecture, presented at the University of
Houston’s American Medical Student Association’s PreMed chapter.
• Audio MP3’s: About Medical Mastery, Admission Requirements, Letters of
Recommendation, and Medicine as a Career
• Study Material: Biostatistics, Definitions and Differentials, Ethics of
Healthcare Organizations, Neurology Questions parts 1 and 2, Research
commentary, Statement of the definition of true science, Somatosensory Pathways,
Processes and Systems, Statistics PowerPoint, and the USMLE eBook.

• What the admissions committee is looking for and tips
for the interview.
• Getting the residency you want and information about the Personal Statement.

• Second Edition Diary of a PreMed Student
• Checklist: Getting Organized
• Show Notes: Getting Organized
• Articles: US, UK, Canadian med student career choices, Letters of
Recommendation
• MCAT: Biochemistry Questions and Answers
• MindMap Contents:

• Advice about medical school preparation, especially
comment on consistency and reliability.

i. 1. Getting organized: graphical and narrative descriptions of the Master
Application Binder
ii. 2. Professional Email Account references. Make sure the email account you
use doesn’t have an embarassing title that the admissions committee might
notice.
iii. 3. A reference tool for Password Organization. Welcome to modern medicine -
be prepared to have to remember more ID’s and passwords than humanly possible.
iv. 4. Transcript request template.
v. 5. Address label template.
vi. 6. Transcript follow-up checklist template.

• How graduate GPA factors into the equation for medical
school and MCAT tips.

vii. 7. Official GPA calculations of the American Medical College Application
Service, including a graphical insert from my actual application and a
narrative.
viii. 8. A Microsoft Excel GPA calculator template for you to manipulate to
predict what your GPA will be come application time.
ix. 9. Sample list of academic honors important for you medical school
application.
x. 10. Resume template.
xi. 11. Sample phrase for volunteer community activities.
xii. 12. Undergraduate research description samples.
xiii. 13. My personal essay.
xiv. 14. My entire medical school application. See all of the biographical and
personal questions you have to answer in advance! There is a lot more to write
than the personal essay.
xv. 15. Secondary application essays. Most medical schools require an additional
application, besides the centralized application service, which comes with
multiple short essays.
xvi. 16. Medical School Application Summary Page (sample). Get an inside look at
the application cover page that admission committees see first!
xvii. 17. The original diary of a PreMed student, unedited and written while on
the medical school interview trail.
xviii. 18. Medical School Essay – HELP. 10 steps to writing the personal
statement along with 5 DO’s and 5 DON’Ts.

• How much do my goals for my career affect my chances of
being accepted and an assessment of how competitive my application is right now.

xix. 19. My Practice Vision: The second personal essay. The general question is
“How do you see your career playing out 5-10 years after medical school?”
xx. 20. Checklist for writing the personal essay.
xxi. 21. How to get STRONG and plenty letters or recommendation.

• What is the best way to log volunteer hours? I mean, is
it a cumulative report from the beginning of undergraduate or is any work done
prior applicable as well?

xxii. 22. The coveted letter for an invitation for an interview (sample now an
expanded section!).
xxiii. 23. Common details about interview details (sample itinerary).

• Information about non-US medical schools, particularly
Caribbean schools.

xxiv. 24. List of Caribbean Medical Schools
xxv. 25. Medical school admission requirements.
xxvi. 26. List of Allopathic medical schools
xxvii. 27. List of Osteopathic medical schools

• How do you start to become a doctor and Pre-Med?
• What are the steps to become a doctor for someone who has NO education (at
least on paper)? Where do I start?
• How do I keep myself motivated…I know this is what I want to do but other
students always seem to keep discouraging me.

xxviii. 28. Deciding on a career in medicine (article)
xxix. 29. Personal essay (sample) for MD/PhD program
xxx. 30. The Modern Medical Scrolls E-book. 1,275 pages of medical student notes
written for each other…and themselves. This .pdf file contains the parts of
medical school that you’ll actually want to remember!

CD Number 2 contains the following answers to your
questions: subsequent CD’s are only $17!

• How can nontraditional applicants create a competitive
AMCAS application and how do I maximize the personal statement and interview to
express my viewpoints.

• Video Tutorial: How to write the Personal Essay in 10 Steps. Also, 5 DO’s and
5 DON’Ts!

• How do I compensate for a low GPA? How do grades from a
harder school compare to presumably easier schools? Besides the MCAT, are there
other ways to demonstrate academic strength? Do the admissions committees
already understand these discrepancies and account for them when reviewing
applications?
• Overcoming a low GPA (under 3.4). How to get back into the swing of things
after a break from school.
• How do community college courses affect your chance of admission?

• Audio MP3’s: The Perfect GPA: No matter what your grades! Sound ridiculous?
• Study Material: Chest x-ray primer, EKG primer, Most Common Female
Reproductive Problems, Hemorrhage, History and Physical Checklist, History and
Physical Pocket Card, Hormone Chart, Psychological Assessment, Tachyarrhythmias
101
• Checklist: The Personal Essay.
• Articles: Euthanasia, Neurenberg, The Personal Essay, Threats To Validity
• MCAT: Pathophysiology

• Getting into medical school in general and specifically,
how much is medical school going to cost me.

• MindMap Additions: The Perfect GPA, Military Experience, Financial Assistance

CD Number 3 contains the following answers to your
questions: subsequent CD’s are only $17!

• How to improve my chances of getting into medical
school.
• How do I get my application recognized among the rest?

• Video Tutorial: The Construct – Part A. Write
your entire medical school application way in advance! Now!! Think through every
step of the process and use this to objectively assess the strengths and
weaknesses of your application.
• Audio MP3’s: Financial Assistance, The Construct – Part A.
• Study Material: Basic Eye Exam, Blood Smear, Dermatology – Skin Neoplasms, Lab
Values 101, Moguls – heart shadows on x-ray, Neuroradiology, Opthamology
• Checklist: The Construct – Part A.
• Articles: False Hopes – Best Data, Human Subjects Research Training, Research
Commentary, Research Description (sample) Teaching Evidence-Based Medicine,
Threats to Validity.
• MCAT: General Chemistry.

• What do you think about post-bacchleurette programs?
Speak about master’s programs before entering medical school for someone that
needs to enhance their academic background.

• MindMap Additions: Research: The Role Of Research In Your Medical School
Application.

CD Number 4 contains the following answers to your
questions: subsequent CD’s are only $17!

• Video Tutorial: The Construct – Part B. Write
your entire medical school application way in advance! Now!! Think through every
step of the process and use this to objectively assess the strengths and
weaknesses of your application.
• Audio MP3’s: The Construct – Part B, Financial Assistance.
• Study Material: Infrared Spectroscopy parts 1-3, Mental Status Examination,
Renal Disease Chart, Stem Cell Research, Vitamins, History of Present Illness (HPI)
and assessing the patient’s mental status.
• Checklist: Financial Assistance Opportunity Exploration, The Construct – Part
B
• Articles: Financial Assistance For Medical School: An oxymoron?, Medical
Futility, Suicide, The Tarasoff Case, The Ethics Movement
• MCAT: Physics

• The interview process and comment more about the path of
the nontraditional student.
• How to make my application standout and how to get an internship or shadowing
opportunity as an undergraduate.

• MindMap Additions: Having a Successful Interview, Volunteer Activities, Uncut
Interview Diary, Diary of a PreMed Student (2nd Edition Guide), Interview Topics
(85 pages!).

CD Number 5 contains the following answers to your
questions: subsequent CD’s are only $17!

• Is it worth taking the MCAT for the third time?
• How should a Pre-Med student study and/or practice for the MCAT?

• Video Tutorial: How To Study For The MCAT And More: The Proven 5-Step Study
Method
• Audio MP3’s: How To Study For The MCAT And More: The Proven 5-Step Study
Method
• Study Material: Neonatal Resuscitation, Behavioral Science Part A, Behavioral
Science Part B, Psychiatry Review
• Checklist: Maximizing Your Study Methodology
• Articles: 100 Years After The Flexner Report, Feedback In Clinical Medical
Education, Impact Of Formal Continuing Education, Systematic Review Of Physician
Performance
• MCAT: Biochemistry Part A, Biochemistry Part B, Evolutionary Questions
• MindMap Additions: How To Study For The MCAT And More: The Proven 5-Step Study
Method

CD Number 6 contains the following answers to your
questions: subsequent CD’s are only $17!

• Video Tutorial: The Power Of Exploiting Your Competition & Demonstration Of
Navigating The MASTERMIND Map.

• I really would like some more information regarding your
thought process upon your decision to leave the military and pursue a career in
medicine. Also, how did you articulate your experiences in the military in your
application/personal statement? What type of responses did you receive from
medical schools regarding your military experience?

• Audio MP3’s: Opening Lecture at the University of Houston Pre-Med Club, The
Power Of Exploiting Your Competition & Demonstration Of Navigating The
MASTERMIND Map.
• Study Material: Antibiotic Medications, Anti-Mycobacterials, Neuroscience
Review, Parasite Note Cards
• Articles: “I Don’t Know” – The Three Most Important Words In Education,
Learner-centered Approaches In Medical Education, ECFMG Information Booklet and
Certification Fact Sheet.
• MCAT: Pathology
• MindMap Additions: Legal Documentation, Work History Template, References,
Certifications, The Professional Email Account, Journaling, Extracurricular
Activities

FUTURE CD TOPICS:

• Also, are the MCAT preparation courses worth the money?
• Interviews with doctors for comparison of what I’ve heard and insight on the
application and interview process.
• What admission officers DON’T want you to know about the process and some big
misconceptions about medical school.
• The reality of medicine. What being a doctor means? I mean, tell me about the
day-to-day goings on of an actual doctor, not what is shown on television.
• What about the “unprepared” medical student that didn’t decide to become
Pre-Med until after college and therefore didn’t take advantage of a true
academic advisor?
• LAST BUT NOT LEAST: insider medical school practice tests – the real thing!

====================================================

Mission Statement
“Medical Mastery seeks to podcast meaning into medical education by combining
faith, high-quality lectures, and charity.”

====================================================

In this episode:

ANNOUNCEMENTS

PREPARING: What is my competition doing?

HOW TO GET A STRONG LETTER

TO SEE OR NOT TO SEE: There is no question.

WHEN TO ASK

QUICK TIP: Questions to ask in order to choose the right letter writer.

QUICK REFERENCES

I am your host, Daniel Williams, MD.

ANNOUNCEMENTS:

1. MICU month - hanging in there…

2. The PreMed Lecture Series. It’s going well and I now have an entire system for premed students to compile their entire medical school application 1-3 years in advance! Why wait? Write it now. Have it reviewed by me and faculty over a longer period of time greatly increases the power of the application, demonstrates a motivated, clearly goal-oriented candidate, and will increase your chances of getting accepted into medical school.

Many have expressed concerns about weaknesses in their application, such as failing or close-to-failing grades, or poor MCAT scores.Folks I overcame these obstacles and you can too! These questions are all being addressed in my coaching course and I want to personally review your application contests. From your personal essay, to the way you describe your work history - I want to see it.

Sign up for the automatic updates on www.MedicalMastery.com and you will be on the early notification list for the details about this coaching course as the next course approaches. This year I’m automating the coaching coarse complete with audio/video how-to tutorials, checklists for every step of the way, my entire medical school application to be used as a template, personalized feedback on your application and much more! Sign up today!

3. Diary of a Pre-Med: A 16-Step Guide. This book is available for free and emailed to you immediatly after you sign up for automatic updates on www.MedicalMastery.com. This is the first edition book that I wrote as a 4th year medical student as a result of my collaboration with premedical students. Of course, the coaching course that you’ll hear about through that email newsletter is the steroid-version! Sign up free right now!4.

Get my favorite 2,500 MCAT questions on CD-ROM for only $27. Get your MCAT Questions by clicking “BUY NOW” in the upper left of this website!

Satisfaction GUARANTEED or your money back! Send it back if you don’t like it and get a full refund…NO RISK.

====================================================

PREPARING: What is my competition doing?

Getting any letter of recommendation (LOR) from a physician or undergraduate faculty can by daunting. With limited face-time, busy schedules, and such high expectations for a LOR, how in the world are you supposed to get 3, very solid, letters from reputable doctors?Let’s start with a discussion about the “PreMed Committee”. This is actually an official entity that medical schools care about (not necessarily anyone else). It is made up of a (somewhat) official Premedical Academic Advisor and 2 underlings, which are often other faculty.

In the late ‘90’s and early ‘00’s, this was still a robust entity found in all but the smallest colleges.There have been massive cutbacks in funding nationally and the result has been fewer and fewer committees that actually know the real scoop. Some of them are registered members of the National Association of Advisors for the Health Professions. This organization attempts to educate non-physicians about the premedical application process. While this is better than nothing, they don’t know what they’re talking about from first-hand experience.In short, get your letters of recommendation from members of your PreMed Committee if you have one PLUS one from a physician.You typically want one from your advisor and 2 from faculty ( the standard carte blance answer). I say if a physician doesn’t write you a letter you’re shooting yourself in the foot.Sidestep all the guesswork on the part of academic advisors and get a physician to evaluate you.

Of course, the quality of the letter is the most important thing.If the strongest letter is from your postman, that’s the one you want! More about that in a minute. I still say that getting to know and perhaps shadow a physician is the best way to get the strongest letter.

HOW TO GET A STRONG LETTER

Relationship matters! You don’t want any old letter of recommendation. You want a “strong” letter of recommendation. What’s the difference?

When you approach a potential letter-writer, you should ask “Are you able to write me a strong letter of recommendation?” Physicians and faculty know that this little adjective means, perhaps more than you do, so make sure you say it that way. If they hesitate, decline, or in any way don’t convince you that they will write a strong letter, then don’t use their letter!Give the writer a copy of your resume or CV, transcript, research papers, and any other documentation that will allow them to see parts about your application that they would have no other way of knowing about.

TO SEE OR NOT TO SEE:

There is no question.Once you find the right person to ask, you will give them a standardized form from the AMCAS. It asks them specific questions about their relationship with you, projects they worked with you on, and how long they’ve known you. This is why it’s important to meet and start grooming someone early that may be able to write you a letter.

There is a section on the form for you to sign. Here you have the ability to waive the right to see the letter. Virtually everyone waives it because the medical schools prefer it that way. This way the writers feel free to put negative comments if they want. Of course, you don’t have to worry about that because you have known them and worked with them for a long time and specifically asked them if they could write a strong letter. They said yes! Go ahead and waive.

It is polite to write thank you notes for many occasions. Writing one to letter writers and interviewers is no exception. Do this as a common courtesy.

WHEN TO ASK

When to ask – start a relationship early, they ask how long. Relationship is harder than getting the letter. The letter should be a natural step in your relationship. You can ask early in undergrad before they forget you. They will at least take notes on your packet and write it later, so that it will reflect a more recent date by the time of the application.

====================================================

QUICK TIP:

When selecting someone to write you a letter, consider the following:

• Have they written letters of recommendation before?

• Is this a physician that practices as some small independent place and would, therefore, have no real idea what admissions committees are looking for these days?

• Do you have a good, close working relationship with them, or do they not even know you by name for whatever reason? (large university, no collaborative research projects, mediocre student…)

QUICK REFERENCE

Here is more than you want to know about the recent FAQ’s regarding medical school application letters of recommendation:

http://www.aamc.org/students/amcas/amcaslettersfaq.htmShopping for a PreMed advisor? See if your local university even has one. Here’s a link to see what pre-med advisors are telling each other:

http://www.naahp.org/resources.htm

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Charity of the Month for April 2008: WarmBlankets.org will receive all donations made in the upper left hand corner of www.MedicalMastery.com.

Charity Mission Statement”

The mission of Warm Blankets Orphan Care International is to restore the lives of orphans in partnership with churches, corporations, organizations and individuals who have a passion to help needy, parentless children.

“Testimonial”Religion that God our Father accepts as pure and faultless is this: to look after orphans and widows in their distress and to keep oneself from being polluted by the world.” - James 1:27″

====================================================

Mission Statement

“Medical Mastery seeks to podcast meaning into medical education by combining faith, high-quality lectures, and charity.”

• Words of advice
• Questions that identify your preparedness for a career in medicine
• Importance of life experiences
• QUICK TIP: Things you can do right now do help you decide if medicine is right for you
• QUICK REFERENCE:
  • Stimulating research papers on US, UK, and Canadian medical students’ career choices
  • 3 career questionnaires

Let me preface my remarks by saying that from now on you should avoid career advice from anyone that has no experience with medical school. This includes family, friends, professors, and sometimes Pre-Med Advisors. What many notice is that people often project their own impression and reasons that they chickened out and didn’t follow their dreams onto the enthusiastic Pre-Med student.

Word of advice: Ignore the crotchety old doctor that tells you not to do it because of the influence of insurance and governmental regulations of recent decades. Not that you would listen to them, but if you educate yourself on the market you’re entering and still want to do it, you won’t have to.

When you account for the diversity of people entering into the medical profession, the reasons that they site for becoming interested vary widely. Some have people have always known they wanted to practice medicine, others are not so sure, and still others decided a little (or a lot) later in life. Whatever your background, I support you! None of these approaches will hinder you from reaching your goals.

So consider your sources carefully! This is all the more reason to plug into Medical Mastery.com and read our insiders advice and get automatic email updates!

So, how in the world are you supposed to know if medicine is right for you? Open a new text document or grab a pen and answer these questions:

• Are you the type of person that gives of yourself to help others?
• Do you receive satisfaction in helping someone when they’re down? How do you really know? Have you done it?
• Would you consider yourself a concrete, logical thinker or an abstract thinker?
• Have you had any exposure to the medical field, either through family or volunteering?
• Do you complain a lot when you’re tired? Have you ever really worked hard before?
• Have you ever been challenged academically? To the point that you weren’t sure if you could survive?
• Have you ever had a life challenge that lasted months or longer? (financial, stress, family illness…)
• Have you ever been financially challenged, or have you always had a stable life?
• Do you know what it feels like to be a helpless patient?

These questions should stimulate your mind and, if so, take notes! How did you react when you read them? Did you have quick, pat answers for every one? Did you think that some of them were irrelevant? Your reaction is important, no matter what it is because you can learn something about yourself!

You may notice that many of these important factors don’t illicit the warm and fuzzy feeling that you may have had when thinking about the nobility of the medical profession. That is because the practice of medicine, though it is noble, focuses on helping people in their greatest need.

If you haven’t had any of the down-and-dirty experiences of life, you’re at a disadvantage to knowing how well you’ll like medicine. You have no way of knowing either how to relate to the patients or how you’ll react when you’re around them all the time. That doesn’t mean that it’s not right for you, only that your ability to know how well you’ll like it ahead of time is impaired. The best you can do is volunteer in shelters, emergency rooms, shadow doctors, and the like. This is adequate for most people, but you should be at least mentally prepared for what you’re getting yourself into. (which is why you’re reading this, isn’t it?)

THINGS YOU CAN DO NOW:

Write a draft of your life goals

Decide what your ideal lifestyle is

Read articles

Shadow physicians

Volunteer

Research

====================================================

QUICK TIP:

Career decisons are more about clarifying who YOU are rather than learning about the career itself. So as you begin exploring the references I’m about to give you, make notes of character descriptions or epiphanies that you have. You will learn how to better articulate what motivates you as you resonate with some of the personality descriptions that you’ll see. Keep these notes in a file. No matter what career you choose, you can find some good phrases to swipe for resumes, cover letters, and personal essays. In fact this is the first step in writing your personal essay - brainstorming and articulating who you are!

QUICK REFERENCE:

USA medical students: http://www.stfm.org/fmhub/fm2004/February/Janet123.pdf

Canadian med students: http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1930324&blobtype=pdf

UK medical students: http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1239861&blobtype=pdf

Career Questionnaires:

http://virtualmentor.ama-assn.org/2006/08/msoc1-0608.html

http://www.aamc.org/students/considering/decision.htm

http://www.free-career-test.com/tfct.asp

http://www.projectcareer.com/?code=G71-CPC50701-Career&gclid=CPLI5KWolpICFT00FQod9gMA_g

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Charity Highlight: Overcomers

Charity Mission Statement

“Overcomers exist to bring hope to hurting people and equip those who care with the knowledge needed to make a difference in other’s lives. Founded on the conviction that no matter how desperate life’s challenges may be, in Jesus Christ there is always solid reason to be optimistic.

We are a teaching ministry: educating people how to encourage each other in the love of Jesus Christ when facing life’s onslaught’s. Imparting the tools needed to comfort and help others with what to say and not to say. We formulate DVD courses to teach lay people across the world how to bring comfort and encouragement and the love of Jesus Christ to all.” http://www.overcomers.org/index.html

Now, reading the lists of medical school entrance requirements is dry. As much as I have tried to avoid using boring lists, they simply can not be avoided when discussing the subject of entrance requirements for medical school.
COMPONENTS OF THE MEDICAL SCHOOL APPLICATION:

• Demographic Data (some of it is optional)
• MCAT - submitted indirectly by the New MCAT Testing History (THx) Report System.
• Official DAT/MCAT/GRE/ACT/SAT Score Reports
• Personal References
• Letters of Recommendation/Evaluation - provided by application service
• Personal Essay
• Volunteer, Research, Work Experience
• Application Fee
• Certification Page
• Photos
• Copy of Visa or Permanent Resident Card (if applicable)
• Secondary Applications

Undergraduate Prerequisites:

• 30 credit hours minimum (unwritten requirement for a bachelor’s degree)
• 1 academic year of Physics
• 1 academic year of Biology
• 1 academic year of General Chemistry
• 1 academic year of Organic Chemistry
• 1 academic year of English

Additional courses are sometimes required. The most recent statistics are from 2005 (yes I know it’s 2008) and they show some medical schools requiring college mathematics, calculus, humanities, biochemistry, and behavioral sciences. Other helpful courses are computer science, genetics, and statistics.

For the MCAT itself, advanced courses in literature interpretation and critical reading will help science major perform better in the Verbal Reasoning section.

Unfortunately, the list of undergraduate courses required varies among the schools themselves. It doesn’t pay to memorize these lists. We recommend that you obtain hard copies of the school catalogues from the institutions that interest you. You can search a specific medical school for its entrance requirements here: http://services.aamc.org/currdir/section2/courses.cfm.
Personal attributes are increasingly important and medical school applicants are under intense scrutiny in this area. Here’s a list of more intangible qualities that medical school admissions committees are looking for in a candidate:

• Altruism
• Compassion
• Humility
• Practical application of knowlege: wisdom
• Life Experience
• Demonstration that you know what you’re getting yourself into
• Knowlede of our nation’s health care crisis
• An idea of what you want your life to be like - take a wild, but honest guess.

====================================================

QUICK TIP: You’ll need these too:

• Access to a computer that is able to connect to the internet
• An e-mail address is required
• Applicants must use only Internet Explorer or Netscape Navigator exclusively to complete the application . Do NOT use Mozilla/Firefox (TMDSAS)
• A laser or ink-jet printer is required to print the Certification Page, Health Professions Evaluation Forms and Transcript Request Forms

QUICK REFERENCE: Application Services

Investigate information about medical school application services:

• American Medical College Application Service (AMCAS)
• Texas Medical and Dental Schools Application Service (TMDSAS)
• Ontario Medical School Application Service (OMSAS)
• American Association of Colleges of Osteopathic Medicine (AACOM)
• American Association of Colleges of Osteopathic Medicine Application Service (AACOMAS)
• AAMC Curriculum Directory for information about medical school curricula and joint, dual, and combined-degree programs.

====================================================

Charity of the Month: Global Tribe - March 2008. Global Tribe will receive all donations made through the “DONATE” button at the top left of this page.

“The mission of Global Tribe is to actively participate in God’s grand plan for every tribe, every tongue, and every nation by building an army of thousands globally who will intentionally declare war on poverty - both physically and spiritually.” (www.GlobalTribe.com)

Anthony Walton, President, Global Tribe: “As a long-time pastor in New Zealand and missionary to many countries, I am so pleased to be a part of what God is uniquely doing through Global Tribe. My heart has always been for the poor, whether those in extreme physical poverty or those in spiritual poverty. GT is identifying and addressing the major issues in all cultures around the world like poverty, HIV/AIDS, social injustices, and caring for orphans around the world. The disenfranchised of the world have a friend in Global Tribe.”

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Mission Statement
“Medical Mastery seeks to podcast meaning into medical education by combining faith, high-quality lectures, and charity.”

Depending on your source, statistics will tell you that only one in ten premed students in college will actually become physicians. According to the American Association of Medical Colleges, 42% of you will actually get accepted. That number is actually high because so many people change their mind and don’t follow through with the application process. There are many reasons for this. In this lecture series, we will explore all of the ones that I get emails about.

Hello, I’m your host Daniel Williams, MD.

Disclaimer

• Raw and uncensored
• Good, bad, and ugly
• No offense intended
• Only my experience

Preview

• I was an Emergency Medicine resident when I started this podcast
• I love my job and wouldn’t want to be doing anything else
• What I do is nothing like the movies
• You can’t make up the things I see
• You wouldn’t want to

Who is this guy, anyway?

I come from a family without college degrees. I knew no one closely that had been through medical school. If I can do it, you can do it! I partied a bit much in high school. Then I Worked in a warehouse. Later, I joined the Army with NO college, as an E1. Those of you that have been in the military know what that experience is like.

On a medical mission to Benin, Africa I got interested in medicine. Specifically, helping the world’s truly needy people. Later I discovered ways that needy populations are served by…THE INTERNET!

I got out of the Army and attended a undergraduate university that had a certified pre-med advisor that attended the state-wide conferences. My MCAT was pretty bad - 26/35. When I got the score in the mail I was depressed for 3 days and didn’t want to talk to anyone or get out of the bed.

What had I done?

I left the Army for this? Took less money for this? Got a degree in Biology that I couldn’t use to mount a decent career, at least not compared to being a physician. I had taken a big risk (on myself), poored in a lot of money and time into extra, “Pre-Med Prerequisite” courses, not to mention the pain of actually trying to do well in them.

Then, the worst blow…my advisor told me to consider another career because of the predictive nature of the MCAT.

Obviously the story doesn’t end here. What happened that changed the course of my career? That’s exactly the point of this article!

My Pre-Med club was active and we toured 4 medical schools in 5 days! Getting to speak with current medical schools was entirely different than anything I had heard. Hearing the insider information changed EVERYTHING!

So, I prayed a lot, then gathered my strength. I decided not to listen to anyone but an MD or a medical student. I even ignored my own father’s misgivings and speeches about how difficult the years of training would be. He just didn’t get it. I’m doing what I love! Without exception, the people that had negative things to say about my choice to be Pre-Med were people that were not fulfilled in their own lives. I had grasped the life lesson I needed to succeed! My mindset was finally right.

I learned everything I’m about to teach you in this course.

As time went on, I began to wonder if others had my experience. I was fortunate to be in an active Pre-Med club with an concerned, participating advisor! What’s happening in other places?

Well, in the Army I learned to take care of my subordinates’ needs. In medical school, I naturally spent 4 years working on the student web site. Pre-Med student from in and outside the U.S. contacted me through Google searches and asked for advice. That’s when I wrote the Pre-Med Entrance Guide I email to those that get automatic email updates to MedicalMastery.com. This blog post podcast marks the first of my years of experience and tremendous collection of electronic notes.

Nowadays, I’m personally taking 10 people per year on a guided coaching course through the entire Pre-Med process, from A to Z! Starting each June! More details will be released as the time approaches.

What do I do in my spare time? Besides spending time with my family, I give tours of the schools and cadaver labs, National Youth Leadership Program cadaveric airway labs, Dr. Reye’s High School Program tours and Q&A sessions, and ACLS instruction.

Mission Statement
“Medical Mastery seeks to podcast meaning into medical education by combining faith, high-quality lectures, and charity.”

• a continuous process in the testis
• in a normal male, there’s always mature sperm-in time.
• in space, there are cells at different stages of maturation
• continuous in time but discontinuous in different places along the seminiferous tubules

Looking at x.s.

• the spermatogonia are closest to the basement membrane
• the mature sperm-spermatozoa-are closest to the lumen of the seminiferous tubules
• Test question-there’s three processes to spermatogenesis-1) mitosis 2) meiosis 3) spermiogenesis
• To get from the spermatogonium, to spermatid, to spermatozoa
• spermiogenesis-morphological change from the spermatid to the mature spermatozoa
• this takes morphological and biochemical changes, not mitotic or meiotic
• SPERMATID à MATURE SPERMATOZOA
• note-to get from the spermatogonium to spermatid, you need the mitotic and meiotic processes
• spermiation-the release of mature sperm into lumen
• mitosis à meiosis à spermiogenesis
• Process up to primary spermatocyte involves mitotic events-that is, conversion from spermatogonium to primary spermatocyte is done via mitosis
• In pre-pubescent boy, there’s only Sertoli cells and spermatogonium
• everything’s arrested until puberty-and surges in testosterone
• Conversion of primary spermatocyte to secondary spermatocyte is meiosis I
• meiosis I, the first maturation division
• Meiosis I: primary spermatocyte à secondary spermatocyte
• Conversion of secondary to spermatid is meiosis II
• Meiosis II: secondary spermatocyte à spermatid
• Then, spermiogenesis-this where the flagella is produced

Six true divisions of spermatogenesis-six true “families” of cells that become sperm

sertoli cells à spermatogonium à primary à secondary à spermatid à spermatozoa

• Males reproductive system is like a tube-seminiferous epithelium lumen, vas deferens, epididymis, urethra
• Blood-testis barrier-a function of the sertoli cells(non-germinal element of the seminiferous epithelium)
• sertoli cells, also nurse cells,
• germ cells literally pushed into the cytoplasm of the sertoli cells, the same as if you took the Pillsbury Dough Boy and went poke into his little tummy, made indention, then put marble into it-marble is the germ cell
• Between individual sertoli cells, there are tight junctions-they act as a barrier between the seminiferous epithelium from the great lumen
• The microenvironment in the basal compartment is very different from the semi-lumen compartment

Nondisjunction-occurs during meiosis in the oocytes

• Trisomy 21-Down’s Syndrome-failure of meiosis in the egg
• results in some brain retardation, infertile progeny, heart problems, etc.
• Amniocentesis and chorionic villi used to detect
• 45XO, Turner’s Syndrome-no ovarian development
• woman looks pre-pubescent
• Woman with Down’s Syndrome can now become pregnant-do produce own eggs-they just need influx of hormones to induce proper ovulation

• During ejaculation, a male sends out anywhere from 100-300 million sperm
• 20 million per ml is getting to the point where fertilization will not happen
• Sperm aren’t fully capable of fertilizing when they are ejaculated
• As they move through the vagina and passages, they are capacitated
• proteins removed, etc..
• Capacitation is defined as the final step of sperm maturation consisting primarily of changes in the acrosome that it prepare it to releases the enzymes required to penetrate the zona pellucida, a shell of glycoprotein surrounding the oocyte
• THE SPERM GETS CAPACITIZED

Questions

Which two substances inhibit GnRH secretion?

Dopamine and endorphins

What neurotransmitter stimulates GnRH secretion?

Norepinephrine

What is the rate limiting step in LH and FSH production?

GnRH dependent availability of the Beta subunit

What does GnRH require for its biological action on gonadotrophs?

Ca

Describe the GnRH to gonadotroph binding and activation process.

GnRH attaches to a plasma membrane glycoprotein receptor and, after binding Ca,

calmodulin acts to alter the activity of enzymes and cytoskeletal proteins involved in the

process.

What is the rate of release of LH and FSH during the follicular phase?

One pulse per hour

What controls gonadotropin secretion during the follicular phase?

Negative feedback of estradiol

What causes the midcycle gonadotropin (LH) surge?

Positive feedback action of estradiol

What hormone facilitates the release of LH and FSH during the midcycle LH surge?

Progesterone

Does the GnRH pulse frequency increase or decrease during the luteal phase?

Decrease

What hormone(s) are responsible for this?

Progesterone and endogenous opioids

How do you treat Kallman’s Syndrome (1^o hypothalamic amenorrhea)?

Exogenous GnRH pulsing

Why is hyperprolactinemia frequently accompanied by hypogonadism or amenorrhea?

Prolactin in excess shuts off pulse generator.

What percentage of germ cells are ovulated in the normal female?

0.1%

About what % of oogonia are produced after a woman enters puberty?

O%

Dose the process of Prophase I to Metaphase II occur before or after the LH surge?

After, it is what initiates the resumption of meiosis.

Which type of follicle can be identified by the presence of Call-Exner bodies?

Graffian or antral follicle

The innermost granulosa cell layer is called the …

corona radiata

What is the most mature stage of a follicle that can be achieved in a pre-pubertal

­ female?

Pre-antral follicle.  The graffian follicle requires FSH and thus a mature hypo-pit-ovarian

axis.

T or F.  Folliculogenesis is linked to hormonogenesis in the ovary?

True

The aromatase system that converts androgens to estradiol is LH or FSH induced?

FSH

What is the underlying factor in the elevation of estradiol levels that triggers the LH

surge?

Size & growth of the pre-ovulatory follicle.

What are the 4 oocyte extrusion mechanisms theorized?

1) proteolytic (plasmin)

2) mucification

3) muscular (tension)

4) angiogenic & inflam.

What is the non-pregnant life span of the corpus luteum

14 days

What are the corpus luteum granulosa cells dependent upon for the synthesis of

progesterone?

LDL

T of F. Progesterone is secreted by the corpus luteum in a pulsitile fashion?

True.  Reflective of the LH secretion that the corpus luteum is dependent.

What drug do you give for anovulation?

Clomiphene

Does the estrogen:progesterone ratio change before labor, in humans?       NO

In sheep?                                                                                            YES

What plays an important role in the stimulation of myometrial activity in humans?

PGs

How do the myometrial cells communicate with one another?

Gap junctions

What stimulates gap junction formation?

Estrogens and PGs

What inhibits gap junction formation?

Progesterone & Indomethacin

What substance acts to decrease intracellular Ca?

cAMP

What acts to increase intracellular Ca?

PGs, oxytocin, IP₃, & channels

How does ritodrine act to stop labor?

Activates adenylate cyclase Þ increased cAMP

Name 2 other drugs used to stop labor.

MgSO₄ & Nifedipine

Which Disorder do you treat with oxytocin, Prolonged latent or Protraction disorder?

Prolonged latent

What is the most important factor in Fetal Acid-Base Balance?

Uterine-fetal blood flow

What helps cause the pCO₂ gradient between fetal and maternal circulations?

Maternal hyperventilation

What is the maternal compensation that occurs in response to the fetal kidneys not being able to handle non-carbonic acids like uric acid?

Increased maternal GFR

T or F.  Normal labor is associated with a ß pO₂, ß pH, ß HCO₃, Ý base deficit, & an Ý pCO₂.

True

Which stage of labor ends with complete cervical dilation?

Stage I, active stage

Which stage of labor ends with delivery of the placenta?

Stage III

T or F.  To end stage III of labor so you can get back to your repro studying, just pull on the cord until it comes out.

False.  Will cause inversion of the uterus and hemorrhage

How many total number of consecutive divisions take place to get to the term fetus?

42

T or F.  Mothers tend to have wide variance in their offspring’s birthweight?

False, you silly goose.

What is the limit of caloric intake/day before the weight of the conceptus decreases?

1500 cal/day

T or F.  If you are a fetus of a rather large size, your chorionic villi surface area will be inceased proportionally?

True

Is the neonate more sensitive to increased pCO₂ or decreased pO₂?

pCO₂

How does the neonate change his/her minutes ventilation?

Increases the frequency of respiration

What percentage of the combined ventricular output does the placenta normally receive?

40%

What happens to this % after birth?

The lungs get it.

Why is fetal myocardial activity, as far as cardiac output goes, limited?

Aortic and pulmonary arterial pressures are equal

Within how many hours after birth does the ductus arteriosus close?

10-15

The closure of the ductus arteriosus is influenced by what factor?

The increasing   pO₂

What happens to ventricular output after birth?

LVO - increases 2-3X      RVO - increases 1-2X

What are the 5 factors that contribute to the decrease in pulmonary vascular resistance?

1) lung expansion

2) clamping of cord

3) increased pO₂

4) decreased pCO₂

5) increased pH

When does the fetus experience the most rapid weight gain?

32-38 weeks gestation

What enables the neonate to make the adjustment from anaerobic met. to aerobic met.?

Increase in # of mitochondria

T or F. Neonate brain can utilize ketone bodies.

True

What is substituted for glucose as a metabolic feul in neonates?

Fat

T or F. One problem with babies who are hypoxic is that they can’t oxidize FFA to

maintain blood glucose.

True

What is one condition that you see neonatal hypoglycemia?

Maternal uncontrolled diabetes

What is the most important determinant of fetal blood temperature?

Maternal arterial blood temp.

Non-shivering thermogenesis occurs where?

In brown adipose tissue

What controls thermogenesis in brown adipose tissue?

Sympathetics; NE is neurotransmitter

Who’s thermoregulatory ability is greater, adults or neonates?

Adults.  Neonates capacity is ¼ that of the normal adult

What is the range of optimum body temperature in neonates?

36-37.8⁰C

What substance, through increase in cGMP, increases uterine blood flow?

NO

In the first trimester do the uterine cells undergo hyperplasia or hypertrophy?

Hyperplasia

Hyronephrosis of pregnancy is usually limited to which side, right or left?

Right.  Sigmoid protects the left.

What are the 3 signs of pre-eclampsia?

Hypertension, proteinuria, edema

What happens to maternal serum creatinine during pregnancy?

Decreases

What happens to creatinine clearance during pregnancy?

Increases (50% increase)

Why does it take more Ang II to get a pressor response in pregnancy?

Increase in vascular refractoriness.

What happens to plasma osmolality during pregnancy?

Decreases to about 290-280 mOsm/L

What heart sounds (S1,S2,S3, and S4) are normal in pregnancy?

S1, S2, and S3

Is ESV increased, decreased, or unchanged during pregnancy?

Unchanged

Is EDV increased, decreased, or unchanged during pregnancy?

Increased in both LV and RV

What change serves to protect the mother from post-partum hemorrhage?

Increase in BV and RBC volume.

What happens to pulse pressure during pregnancy?

Increases due to fall in diastolic BP>fall in systolic.

Why does pulmonary resid. Vol., expir. reserve, and funct. Resid. Cap. all decrease

during pregnancy?

The enlarged uterus compresses the thorax

What happens to pulmonary vital capacity during pregnancy?

unchanged

What changes contribute to the “breathlessness of pregnancy”?

increase in pO₂; decrease in pCO₂

Which of these four crosses the placenta, TRH, iodine, T₃, T₄?

TRH and iodine

What other things, besides the placenta, can produce hCG?

1) hydatidiform mole

2) choriocarcinoma

3) fetal tissue

hCG has identical a-subunits with what other 3 hormones?

FSH, LH, TSH

Therefore, we have to measure hCG by measuring which subunit?

b

What hormone serves to stimulate and maintain the corpus luteum?

HCG

What hormones does hCG stimulate the corpus luteum to produce?

Estrogen, progesterone, relaxin

T or F.  hCG may act on fetal testis to stimulate testosterone production thus leading to

early masculinization?

True

When is serum hCG levels at its highest level?

8-10 weeks

When can most take home kits detect pregnancy?

2 weeks after conception

When the hCG does not double every 2-4 days starting at 4-5 weeks gestation, what

concerns you?

Ectopic pregnancy

Lab returns hCG levels of > 200,000 mIU/ml, what concerns you?

Hydatidiform mole, choriocarcinoma

Which hormone is responsible for the “diabetogenic effect” of pregnancy?

Human placental lactogen (hPL)

Which placental hormone is highest in level at term?

hPL

hPL has a 96% sequence homology with which hormone?

Human GH

What is the main estrogen of pregnancy, E₂ or E₃? Of normal menses?

E₃ (estratriol); E₂

Why does the placenta require a C-19 precursor for estrogen synthesis?

Lacks 17a-hydroxylase

What is the main precursor in estradiol (E₂) synthesis?

Dehydroandrosterone sulfate (DS)

Where does the DS come from, and in what percentages?

50% maternal adrenal; 50% fetal adrenals

What is the main precursor in estriol (E₃) synthesis?

16-a-hydroxydehydroepiandrosterone - 16a-OH-DS

Where does the 16a-OH-DS come from and in what %?

90% fetal adrenal; 10% maternal liver & adrenal

What is the largest organ of the fetus?

Adrenal

If you had a placental aromatase deficiency, what would you expect?

1) virilization of mother & fetus

2) very tall affected males

What is the most common cause of ß placental estrogen?

ß LDL-cholesterol

What happens to the placental estrogens in fetal erythroblastosis?

Production increases

What three substances are used frwquently to predict fetal abnormalities?

E₃, aFP, hCG

What does the trophoblast need for progesterone synthesis?

LDL cholesterol

You have a fetal death.  What happens to the levels of progesterone and estrogen?

Estrogen  ß, Progesterone unchanged

Why is the progesterone level unchanged when fetal death occurs?

Unaffected because it doesn’t require fetal input.  90% of cholesterol comes from maternal plasma.

When can you perform ultrasound?                Any trimester

Chorionic villus sampling?                  Only in 1^st trimester (usually 10-12 weeks)

Maternal serum screening                              2^nd trimester (usually done at 16-18 weeks)

Amniocentesis?                                               2^nd or 3^rd trimester

Fetal Blood sampling?                        2^nd or 3^rd trimester

What is advanced maternal age?

> 35

a-fetoprotein is related to what other plasma protein?

Albumin, both encoded on chromosome 4

What is the most frequent serious fetal malformation in the US? 2^nd most common?

CHD, Neural Tube Defects

Why is it most effective to give folic acid before the woman is pregnant?

The neural tube closes at 3-4 weeks, and folic acid has been implicated in reducing the

requency in NTDs.

What causes the MSAFP screening to be normal, even if there is a NTD?

Skin covering the defect.

What is the most common reason for false + MSAFP results?

Underestimation of gest. Age

T or F. NTDs have been associated with maternal diabetes mellitus.

True

What other drugs have been implicated in an increased risk of NTDs?

1- carbamazepine

2- Valproic Acid

3- retinoic acid

In what normal condition would you expect a doubling of MSAFP?

Twin gestations

What is the “lemon sign” (scalloping of the frontal bones) indicative of?

NTD (also banana sign)

If you have…                                                                           then you have…

Ý AFAFP & Ý AchE                                                                 NTD

Ý AFAFP & ß AchE                                                                 some other fetal defect

Ý MSAFP, normal AFAFP, (-) AchE                                        most likely normal

What is the most sensitive marker for Downs syndrome?

HCG

What lab values do you expect in a Downs syndrome fetus?

ß MSAFP, ß E₃, Ý hCG

How is MSAFP measured?

In Multiples of the Mean (MOM)

What lab values do you expect in trisomy 18?

ß MSAFP, ß E₃, ß hCG

What is the earliest that amniocentesis can be performed?

12 weeks

What are some disadvantages of amniocentesis?

1) takes 14 days to complete routine tests, 2) if preg termination to occur, it’s more   complicated.

What is the “big scare” concerning chorionic villus sampling?

Limb reduction defects

T or F. You can test for NTDs with chorionic villus sampling?

False. Have to do MSS.

Which vessel in the fetus has the greatest O₂ saturation?

Umbilical vein

Which part of the IVC has the greatest 0₂ saturation due to streaming?

Left and Dorsal portion

Via which mechanism does the fetus increase its CO the most?

By increasing its HR

The fetal heart is most sensitive to preload or afterload?

Afterload

Which has the greatest influence on fetal HR, parasympathetic or sympathetics?         Parasympathetics

What is the vagal response from the stretch receptor input of increased BP?

Slowing of HR & ß CO

On FHR tracings, you notice that the HR is bradycardic.  What worries you?

The baby may be hypoxic and have HTN

What usually occurs first in response to fetal “distress” (hypoxia)?

Increase in catecholamines

The ductus arteriosus connects which two structures?

Pulm. A. and aorta

The crista dividens directs flow from what to what?

IVC to the Left Atrium

The crista interveniens directs flow from what to what?

SVC to the Right ventricle

Which has the greatest O₂ stauration…

The RA or the LA?                                                                  LA

The umbilical artery or the umbilical vein?                              Umbilical vein

IVC or the ductus venosus?                                                    Ductus venosus

Umbilical artery or ductus venosus?                                       Ductus venosus

Umbilical vein or ductus venosus?                                          About equal (UV)

Which ventricle receives the blood that will supply the brain and myocardium?

LV

Fetal or Adult…

Which has the greatest CO (ml/min/Kg basis)                                                fetus

Which has the greatest CO (ml/min basis)                                                     adult

Which operates at the top of the cardiac function curve?                               fetus

Which has the greatest pO₂ value (normally)                                                 adult

What are the 5 fetal responses to “distress” (hypoxemia)

1) increase in catecholamines

2) slowing of HR
3) increase in BP

4) redistribution of CO to heart, brain, adrenal

5) increase in angiotensin II and AVP

What is the AAP recommendation for length of exclusive breastfeeding?

6 months

T or F. Breast feeding decreases the risks of some forms of cancer?

True. (due to hypo-estogenic state)

What is the tail of Spence?

The portion of the breast that extends into the axilla

What germinal layer gives rise to the ducts of the breast?

Ectoderm

What are the ligaments called that connect the breast to the underlying pectoralis?    Ligaments of Cooper

2-6% of women have hypermastia.  What is it?

Accessory mammary glands

How many milk ducts does the normal nipple contains?

15-25

What kind of secretion takes place in the mammary glands?

Merocrine (protein) and apocrine (fat)

What is responsible for the proliferation of the parenchyma of the breast during the luteal phase?

Estrogen

What hormone is responsible for the initiation of milk secretion?

Progesterone falls and PRL remains high

Why does the fall in progesterone initiate milk secretion?

Progesterone is an inhibitor of lactose synthesis

The maintenance of lactation in Stage III of lactogenesis requires what?

Removal of milk

If a woman chooses not to breast feed, how long are Prolactin levels detectable?

14 days

What is the stimulation for Prolactin release?

Suckling

If a mother is playing with her infant and her shirt becomes wet, which hormone is

responsible?

oxytocin

What is the mechanism of oxytocin on the breast?

Causes myoepithelial cell contraction and thus ejection of milk.

What can inhibit the Milk Ejection Reflex?

Stress and alcohol

What is the rate limiting enzyme in Lactose synthesis?

a-lactalbumin (progesterone inhibits)

Which vitamin has to be supplemented at birth because it is not transferred in mother’s

milk?

Vit K

What gives colostrum its yellow color?

b-carotene

What is the #1 component of mature milk?

Water

What does lactoferrin do?

Inhibits growth of iron dependent GI bacteria; protective for newborn

If you were a baby, which do you think would be easier, breast or bottle?

Bottle

How many times will a normal newborn nurse per day?

8-12

T or F. A law of supply ad demand exists between mother and child?

True

What are some signs that a baby is getting enough milk per feeding?

1) 6-8 wet diapers/day

2) loose stools daily

3) regains birth weight at 2 weeks

4) growth charts

Is Hepatitis B a contraindication for breast-feeding?

No

As menopause approaches, what accounts for the decreased estrogen levels?

Lack of follicle develop.

Why do serum FSH levels increase more than LH as menopause approaches?

1) Decreased inhibin levels

2) increased resistance to follicle recruitment

What is the principle estrogen before menopause and where is it made?

Estradiol, ovary

What is the principle estrogen after menopause and where is it made?

Estrone, adipose tissue

What is the underlying cause in the difficulty of sleeping after menopause?

Low levels of free Tryptophan

What dose estrogen therapy do to help sleep quality?

1) reduces the sleep latency interval

2) increases time in REM sleep

What causes the hot flashes during menopause?

a-adrenergic neurotransmission due to loss of estrogen

T or F.  Estrogen supplementation is protective against MI?              True

T or F.  Estrogen acts to increase HDL and decrease LDL?              True

T or F. Estrogen decreases Triglyceride levels?                                 False

T or F.  Estrogen decreases lipoprotein A activity?                            True

T or F.  Estrogen increases the relaxing capacity of the arterial wall?            True

Liver    Ý HDL, ß LDL, ß Cholesterol, Ý TG, Ý Free cholesterol, ß Lipoprotein A

Arterial Wall     Ý relaxing capability

Estrogen

Growth Factors

Heart   Ý Coronary Blood Flow

Ý Arterial Pulsality Index                                 ionotropic effects

Ý Myocardial Contractility

In post-menopausal osteoporosis, what type of bone suffers the greatest loss?

Trabecular Bone

What does an increase in urinary N-telopeptide tell you?

Bone loss is occuring

Does estrogen prevent bone loss or stimulate bone formation, or both?

Both, with a predominance of born formation in the premenopausal age groups.

What are some side effects of estrogen replacement therapy?

1) endometrial hyperplasia & cancer

2) thromboembolism & stroke

3) HTN

4) Breast Cancer

5) gall bladder dysfunction

Why give progesterone with estrogen?

To decrease the risk of endometrial hyperplasia and cancer.

Will a woman, with a uterus, when on continuous estrogen-progesterone therapy experience bleeding?

20% experience bleeding, usually spotting.

How much Ca per day is needed by the post-menopausal woman?

1200 mg/day for Repro

1500 mg/day for Pharm

Gametogenesis- the process of meiosis and cytodifferentiation that converts germ cells into mature male and female gametes, spermatozoa and definitive oocytes respectively.

-        timing between sexes differs

-        diploid —–  haploid

-        2n —– 1n

First meiotic division- involves DNA replication and recombination and yields two haploid 2n daughter cells.

-        Primary oocyte or spermatocyte -  the 4n cell coming forth from the 2n replication

-        The first meiotic cell division produces two secondary spermatocytes in the male or a secondary oocyte and a first polar body in the female.

Prophase

-        the chromosomes condense into compact, double-stranded structures

-        in late stage, the double chromosomes of each homologous pair match up, centromere to centromere, to form a joint structure called a chiasma.

-        The chiasma allows for crossing-over which accounts for an increase in genetic variability.

• the primary oocyte enters a phase of meiotic arrest during the first meiotic prophase.

Metaphase

-        the four-stranded chaisma structures are organized on the equator of a spindle apparatus similar to the one that forms during mitosis.

Anaphase

-        one double-stranded chromosome of each homologous pair is distributed to each of the two daughter nuclei.

-        The centromeres of the chromosomes do not replicate, and therefore the two chromatids of each chromosome remain together; which makes the resulting nuclei haploid, but 2n.

-        They contain the same amount of DNA as the parent germ cell, but half the number of chromosomes.

Second meiotic division - the double-stranded chromosomes divide, yielding 4 haploid 1n daughter cells.

-        no DNA replication occurs in the 2^nd meiotic division

-        the 23 double-stranded chromosomes condense during the 2^nd meiotic prophase, and then line up during the 2^nd meiotic metaphase.

-        The chrosomal centromeres then replicate

-        During anaphase the double-stranded chromosomes pull apart into 2 single stranded chromosomes and one is delivered to each daughter nucleus.

-        the 2^nd meiotic division produces two definitive spermatocytes or spermatids in males and in females it produces one large definitive oocyte and another dimunitive polar body.  The first polar body may undergo the 2^nd meiotic division and produce a third polar body.

-        In the female, the oocyte enters another phase of meiotic arrest during the second meiotic metaphase before the replication of the centromeres.  Meiosis does not resume until the oocyte is fertilized.

Spermatogenesis

-        at puberty the testes begin to secrete increased amounts of testosterone.

-        Stimulates the development of many secondary sex characteristics

-        triggers the growth of the testis

-        triggers the maturation of the seminiferous tubules

-        triggers spermatogenesis

Spermatgenesis

-        cells to undergo spermatogenesis arise from the spermatogonia via mitosis

-        these cells are gradually translocated between the Sertoli cells from the basal to the luminal side of the seminiferous epithelium while spermatogenesis takes place.

-        During this migratory phase, the primary spermatocytes pass without interruption through both meiotic division resulting in the four spermatids.

-        The spermatids undergo the changes that converts them into mature sperm while they complete their migration to the lumen of the seminiferous epithelium.

Sertoli cells

-        maturing spermatocytes and spermatids are connected to the Sertoli cells by tight junctions, gap junctions, and by a specialized junction termed  tubulobulbar complexes.

-        Tubulobulbar complexes- extend into the Sertoli cells; thought to provide a mechanism by which the excess cytoplasm is transferred to the Sertoli cells.

-        As the cytoplasm is removed, the spermatids undergo the changes that convert them into spermatozoa.

-        Finally the junctions with the Sertoli cells break, thus releasing the spermatozoa into the tubule lumen. (termed spermiation)

Spermatozoa

-        head- contains the nucleus and is capped by an apical vesicle (acrosome) filled with hydrolytic enzymes.

-        Midpiece- contains large, helical mitochondria and generates the power needed for swimming

-        Tail- contains the microtubules that form the propulsion system.

-        Errors are not at all uncommon

Spermatogenesis is continuous from puberty until death

-        gamates are produced in synchronous waves in each local area of the germinal epithelium

-        about four waves of synchronously differentiating cells can be observed in any given region of human tubule epithelium at any given time.

In the human male, each cycle of spermatogenesis takes about 64 days.

-        spermatogonial mitosis- 16 days

-        first meiotic cell division- 8 days

-        second meiotic cell division- 16 days

-        spermiogenesis- 24 days

·         Sperm produced in the seminiferous tubules are stored in the epididymis, which is a special duct connected to the vas deferens.

• During ejaculation, the sperm are propelled through the vas deferens and the urethra and are mixed with nourishing fluid consisting of secretions from the seminal vesicles, prostate, and bulbourethral glands.
• As many as 200 million spermatozoa are ejaculated
• Only a few humdred succeed in reaching the ampulla.

Capacitation

-        Capacitation- terminal step of functional maturation that prepares a spermatozoa to fertilize an oocyte; consists primarily of changes in the acrosome that prepare it to release the enzymes necessary to penetrate the zona pellucida of the oocyte;  thought to take place in the female genital tract and to require contact with the secretions of the oviduct.

Oogenesis

• the total number of primary oocytes is produced in the ovaries by the fifth month of fetal life.
• Germinal vesicle - thought to protect the DNA during the long period of meiotic arrest.
• Follicle cells- surround the primary oocyte in a single, squamous layer; oocyte and follicle cells together are termed primordial follicle.

Menarche- (Female puberty)

-        Menstrual cycle- responsible for producing monthly a single female gamate and a properly conditioned uterus to receive a fertilized embyro.

-        Monthly maturation of primordial follicle

-        Concurrent proliferation of the uterine endometrium

-        Ovulation

-        Continued development of the follicle into an endocrine corpus leutem

-        Without fertilization, the sloughing of the endometrium and the involution of the corpus leutem

-        28 days

• begins with menstruation (1-5)
• day 5- the hypothalmus releases gonadotropin-releasing hormone (GnRH) which stimulates to pituitary gland to increase secretions of two gonadotropins—-follicle stimulating hormone (FSH) and luteinizing hormone (LH)
• prior to the inc. secretions of the gonadotropins the primordial follicles thicken from squamous to cuboidal and are then termed primary follicles.
• The follicle cells and the oocyte together secrete a small amount of glycoprotein onto the surface of the oocyte which forms the zona pellucida. The epithelium of 5 to 12 of these primary follicles then proliferates to form a multi-layered capsule around the oocytes and are now termed growing follicles. Some continue to grow in response to the increased FSH, while others degenerate.
• Those that continue to grow take up fluid and form a central fluid-filled cavity called the antrum. These follicles are now termed antral or vesicular follicles.
• At the same time the connective tissue of the ovarian stroma surrounding each of these vesicular or antral follicles differentiates into two layers, the inner layer is called the theca interna and the outer layer is called the theca externa. These two layers become vascularized and the follicle cells do not.
• A SINGLE FOLLICLE CELL BECOMES DOMINANT AND THE REST DEGENERATE
• The dominant follicle cell continues to absorb fluid.
• Cumulus oopherous- the small mass of follicle cells surrounding the oocyte
• large swollen vesicle is now termed the mature vesicular follicle or mature graafian follicle; still has not resumed meiosis.
• Resumption of meiosis and ovulation are stimulated by an ovulatory surge in the levels of FSH and LH
• Day 13 or 14- the levels of LH and FSH rise very sharply (ovulatory surge)

-        stimulates the primary oocyte to resume meiosis

-        the cumulus oopherous expands in response to the ovulatory surge in LH and FSH

Ovulation

-        depends on the breakdown of the follicle wall

-        similar to an inflammation response

-        initiated by the secretion of histamine and prostaglandins

-        within a few hour of the ovulatory surge of LH and FSH, the follicle becomes more vascularized and becomes increasingly pink.

-        The follicle is then displace to the surface of the ovary, where it forms a bulge.

-        As ovulation approaches, the projecting wall of the follicle begins to thin, resulting in the formation of a small, nipple-like protrusion called the stigma.

-        FINALLY, a combination of tension plus the release of collagen-degrading enzymes and other factors by fibroblasts in the region causes the follicle to rupture; NON-EXPLOSIVE.

-        The oocyte, accompanied by a large number of investing  cumulus cells bound in the hyaluronic acid matrix and by some follicular fluid, is SLOWLY extruded onto the surface of the ovary.

-        Ovulation occurs about 38 hours after the ovulatory surge of LH and FSH.

Endocrine corpus leutem-  the ruptured follicle forms this structure

-        the corpus leutem is an endocrine structure that secretes steroid hormones that maintain the uterine endometrium in a conditioned state.

-        If no implantation occurs within 14 days, it converts into a scarlike structure termed a corpus albicans.

Estrogens and Progesterone secreted by the follicle control the uterine events of the menstrual cycle.

At fertilization, the sperm nucleus enters the oocyte, the oocyte completes meiosis, and the pronuclei of the two mature gamates fuse. Fertilization is a complex interaction between sperm and oocyte. If viable sperm encounter an oocyte in the ampulla of the oviduct, they surround it and force their way through the cumulus mass.

When the spermatozoa reaches the tough zona pellucida surrounding the oocyte, it binds with a glycoprotein sperm receptor in the zona (ZP3) and then the acrosome is induced to release degenerative enzymes that allow penetration of the zona pellucida. After penetration, the cell membranes fuse, which causes thousands of cortical granules located just beneath the cell membranes to release into the perivitelline space between the oocyte and the zona pellucida. The substance release by the granules causes a chemical change in the zona pellucida which alters the sperm receptor molecules, thus causing an impenetrable zona, preventing polyspermy.

Fusion of the two membranes also causes the oocyte to complete the second meiotic metaphase and also goes rapidly through anaphase to produce another polar body.  The oocyte is now considered to be a definitive oocyte. The chromosomes of the oocyte and sperm are then respectively enclosed within the male and female pronuclei. The pronuclei then fuse with one another to produce the single, diploid, 2N nucleus of the fertilized zygote.  This is taken to be the Beginning or zero time of embryonic development.

First few days of embryonic development:

Within 24 hours a series of Cleavages begins that subdivides the zygote without increasing its size. The subdivisions in the zygote are called blastomeres.  We are still inside the zona. At 40 hours, the second division is complete which has produces four equal blastomeres.

3 days—- 6-12 cells;   4 days—- 16-32 cells

By the 32 cell stage, the embryo is termed the morula (from the Latin for mulberry)

The cells of the morula will give rise to the embryo proper and attached membranes, and also to the placenta and related structures.

At the  8 cell stage, the blastomeres begin to flatten, developing an inside-out polarity that maximizes cell-to-cell contact among the blastomeres at the center of the mass.

As differential adhesion develops, the outer surfaces of the cells become convex and the inner surfaces become concave.  This is termed compaction. This development of differential adhesion causes segregation of some of the blastomeres to the center of the morula and others to the outside.

There is now an inner cell mass and the outer cell mass. There is some exchange between the two groups, however the inner group generally gives rise to the embryo proper and is thus termed embryoblast, and the outer cell mass gives rise to the membranes of the placenta and is thus termed the trophoblast.

By 4 days, the morula begins to absorb fluid which collects between the cells.

Also tight junctions and gap junctions begin to develop between blastomeres, especially between those of the outer cell mass.  As a result of the tight junctions forming between cells of the outer cell mass, the fluid collects between the cells of the inner cell mass. As the hydrostatic pressure increases because of the increase in fluid, a large cavity called the blastocyst cavity forms. The embryoblast then form a compact mass at one side of this cavity, and the outer cells or trophoblast is organized into a thin single-layered epithelium. The embryo is now termed a blastocyst.   The side of the blastocyst containing the inner cell mass is termed the embryonic pole and the side containing the outer cell mass is termed the abembryonic pole.

Beginning of implantation:

by day 5 the blastocyst hatches from the zona pellucida through the use of enzymes.

After about 6.5 days the blastocyst becomes very tightly adherent to the uterine lining. The adjacent cells of the endometrial stroma respond to its presence and to the progesterone secreted by the corpus leutem by differentiating into metabolically active, secretory cells called decidual cells.  This response is called the decidual reaction.

The endometrial glands in the surrounding area also enlarge and become highly vascularized and edematous.  (Sort of like an inflammation reaction) The uterine lining is maintained in a favorable state and kept from sloughing partly by the increased secretion of progesterone.  (In the absence of an implanted embryo, the corpus luteum normally degenerates after about 13 days) If an embryo implants, the cells of the trophoblast produce the hormone human chorionic gonadotropin (hCG) which supports the corpus luteum and thus maintains the supply of progesterone (Maternal recognition  of  pregnancy).

Ectopic Pregnancies

When a blastocyst implants in the peritoneal cavity, on the surface of the ovary, within the oviduct, or at an abnormal site of the uterus.

Symptoms:

abdominal pain

vaginal bleeding

Surgical intervention required

Applications to clinical practice:

Down Syndrome - trisomy-21; results from nondisjuncton

Amniocentesis- removal and examination of sloughed off cells contained in the amniotic fluid to determine karyotype

Turner syndrome- XO

Kleinfelter syndrome- XXY

Birth control methods

barrier contraceptives

birth control pills

depot preparations

nonmedicated intrauterine devices

RU-486

Sterilization

Assisted reproduction

in vitro fertilization and embryo transfer

gamate intrafallopian transfer

1)     Engagement - Bi-parietal diameter (BPD) descends through the plane of the pelvic inlet.

2)     Descent

3)     Flexion - chin tuck to decrease the diameter passing through the pelvis

4)     Internal Rotation - rotates past the spines

5)     Extension - keep occiput in contact with the pubic arch

6)     External Rotation - will turn same way as internal rotation to line up shoulders in AP diameter

7)     Expulsion

4 Signs of Placental Separation

1)     gush of blood

2)     lengthing of cord

3)     uterus rises in the abdomen

4)     uterus becomes firm and globular

Remember, don’t tug on the cord when the uterus is relaxed.

Treatments for the Neuropsychiatric disorders associated with AIDS:

Mild Neuro-cognitive disorder

• No confabulation

• Difficulty concentrating, unusual fatigue, subjectively slowed down, difficulty in remembering, learning and recalling new info

• Difficulty problem solving, abstract reasoning, and slowin of simple motor performances (finger tapping)

• Be sure to distinguish from delirium and dementia (these have confabulation)

Psychopharmacology - in addition to their usual HIV meds, stimulants (ie, methylphenidate) could be used - BE CAREFUL with drug interactions (CYP 3A4 & CYP 2D6)

HIV Associated Dementia - Signs and Sx

• The cognitive abnormalities in a person with dementia are more profound and more generalized than in persons with mild neuro-cognitive disorder

• Marked mental slowness and deterioration

• With disease progression, pt becomes more apathetic, severely disoriented, and frankly confused

• Slow onset, long lasting

• Difficulty in ADL’s

• Increased irritability, mood lability, delirium, paranoid ideations, auditory and visual hallucinations

- Neuroradiological exam - cortical atrophy (sulci dilation); EEG shows diffuse slowing

- Lab findings - low CD4, increased CSF neopterin and increased CSF quinolinic acid (proteins); ↑ CSF viral load correlated to severity of the dementia

- Course and Prognosis - about 50% of patients diagnosed with AIDS have either asymptomatic neuropsych impairment or mild neurocognitive disorder; poor prognosis

- Treatment

SSRI’s

• Cytalopram (Celexa)

• Escitalopram (Lexapro)

• Paxil (Buroxitine)

• Venlafaxine (Effexor) - good but be careful with the side effects

• Mood Stabilizers

• Valproic acid, and Gabapentin ( NOT Lithium!!)

• Anti-psychotics

• NOT low potency anti-psychs or Clozapine

• Benzodiazepine

• • • Esp. short acting or ultrashort acting

• • • No TCA’s or buproprion (↓ metab can cause toxicity)

• DO NOT USE Sertraline (↑ GI probs), FLuoxetine (can cause serotonin syndrome and has ↑↑ drug interactions CYP 2D6);

• Substance use - use of a substance in a socially acceptable manner (ie glass of wine at dinner)
• Drug misuse - doc using drugs not for medical use (prescribing drugs w.out seeing pts at a $50 charge)
• Abuse - a maladaptive pattern related to a drug you are using leading to clinically significant impairment or distress as manifested by one or more of the following occuring at any time during the same 12-mo period:

1. Recurrent substant abuse resulting in a failure to fulfill major role obligations at work, school, or home

2. Recurrent substance abuse in situations in which it is physically hazardous - your life or the life of others (ie “I can drive”)

3. Recurrent substance-related legal problems (DWI, PI, etc.)

4. Continued substance use despite having persistent or recurrent social or intepersonal problems

The DSM-IV diagnostic criteria for abuse require evidence of repeated occurences within a 12 month period of possible social, legal, or interpersonal trouble related to the substance.

I. Dependence

• aka “habituation” or “compulsive use”

• Psychological dependence- “I need whisky to speak in front of a crowd” or “I need X medication to sleep at night”

• Tolerance

Metabolic tolerance- liver metabolizes the drug quicker

Pharmacodynamic tolerance- adaptation of cells to drugs

Behavioral tolerance- don’t get the same behavioral response after prolonged use

1. Start drinking - lose inhibitions

2. Continue drinking for a year - need twice the alcohol to lose inhibitions

• Withdrawal or an abstinence syndrome is the appearance of physiological symptoms when the drug is stopped too quickly; usually the manifestations are opposite those of the drug

Ex. Cocaine euphoria, no sleep, no eat, ↑ sex; withdrawal ↑sleeping, eating,

depression, and ↓ sex

• Like tolerance, withdrawal is not an all or none phenomenon and usually consists of a syndrome comprising a wide variety of possbile symptoms, with patterns that are different for opiods, depressants, and stimulants

II. Factors that influence recreational drug use and patterns of use

Factors:

1. The physical reward potential

Feel like you have ↑ power (cowboys losing and the player walks on his broken ankle

Boxer is a young guy with many fractures but keep fighting and tolerate the pain

2. Peer pressure

3. Pleasurable effects

4. Social-learning component of drug use

You drink for the first time and throw up all night; your friends tell you that next time they will teach you how to drink.

5. Individual expectations as a component of drug use

Effects the indiv expects to gain from using the drug (relaxing from pot or halucinations from hallucinogenic drugs)

If they are getting the desired effects they will keep taking it

6. Family dysfunction (emotional, neglect, physical, and sexual abuse) leads to

unhealthy coping mechanisms

Patterns of Use:

- Regular daily intake of large amounts

- Regular heavy drinking limited to weekends- pt goes straight to drinking every fri

- Long periods of sobriety followed by drinking binges

III. Alcohol dependence

Primary vs. Secondary alcoholism

70% are primary (people without psychiatric problems to complicate the drinking prob)

30% are secondary (↑ anti-social personality, personality d/o, and MOOD d/o **TQ**

15-20% of female alcoholics and 5% of males have shown primary mood disorders and secondary alcoholsim

20% of male alcoholics and 5% of female alcoholics have shown anti-social personality disorders and secondary alcoholism; the opposite for females

Less than 10% of alcoholics demonstrate schizophrenia or other psychiatric disorder (Brisque’s hysteria) and anxiety disorders

There are an estimated 16 million people who are diagnosed as alcoholics

Prevalence of Alcohol dependance

• The prevalence of drinking is higher and abstention is lowest in the 21-34 year old range

• From 5-13% of the adult population in the USA will demonstrate alcoholism at some time in their lives

• It is important to recognize that alcoholism is a problem of all ages, all religions, all countries, and both sexes

• Higher rates of alcoholism are associated with….

1. Armed services

2. Lower socioeconomic strata

3. Lower income and education

4. Among Catholics

5. Among French and Irish

** don’t believe this 100%**

IV. Etiology

1. Psychological Theories

2. Pleasure theory- you feel great, powerful, euphoric

3. Defense mechanisms

- Denial- I am just a social drinker

- Projections- my wife brought me here but I don’t know why. Why didn’t she brin gher father…he drinks like a fish

- Rationalization - Yes, I drink, but I have to in order to survive at my stressful job

- Fragmentation - Form of denial. I am not an alcoholic…I have been sober for a week

- Minimization- I drink only a couple of drinks (means ½ bottle of whisky and ½ bourbon / night

V. Sociocultural theory - “you are probably an alcoholic because you have not been properly introduced to drinking (ex. Jewish are formally introduced to alcohol, but the Ashkenazies drink less)

• Biological Theory

- Acetaldehyde forms condensation products with biogenic amines

- Acetaldehyde + NE = TIQ (tetrahydroisoquinoline)

- Acetaldehyde + Dopamine = THP (tetrahydropapaveroline)

- Acvetaldehyde + 5HT = tetrahydro-beta-carbolines

• The TIQ Hypothesis

- Suggests that chronic alcohol use significantly reduces the brain’s production of the endorphins, the enkephalins, and the dynorphins

- TIQ was capable of binding opiate-like receptor sites within the brain’s pleasure center causing the individual to experience a sense of well-being

- TIQ’s effects were thought to be short-lived, forcing the individual to drink more alcohol in order to regain or maintain the initial feeling of euphoria achieved through the use of alcohol

VI. Genetic Factors

- Alcoholism runs in families

- On average about 40% of alcoholics have an alcoholic parent

- 2/3 of the studies reviewed, at least 25% probands have fathers who were alcoholics

- As many as 62% of one set of alcoholics had 1 or more relatives in the preceding 2 generations who had “problems with alcohol”

- Women seem to be more vulnerable than men to the impact of familial alcoholism

- Alcoholism was found more frequently than any other forms of mental illness in relatives of alcoholics

Adoption Studies