Question 1

Two people have the same total body mass (70 kg) but one has a much higher percentage of body fat than the other. They both habitually ingest 2.5 L of water per day.
The individual with the higher percentage of fat will have a:

Accepted Answer

A)  Higher extracellular fluid (ECF) volume than the other individual 
B)  Lower rate of water turnover than the other individual 
C)  Higher rate of water turnover than the other individual 
D)  Positive water balance 
E)  Negative water balance

Question 2

A 1-day-old neonate with acute respiratory distress syndrome (ARDS) has moderately severe hypoxemia. Physical examination reveals, dry inspiratory crackles in the lungs and a continuous harsh murmur heard over the entire precordium. Which of the following sets of oxygen saturation (SaO2) values in the cardiac chambers and vessels most likely match those of this patient? $$\begin{array} { | l | l | } 
\hline \text { Right atrium (RA) } & \text { Normal } \mathrm { SaO } _ { 2 } ( \% ) \
\hline \text { Right ventricle (RV) } & 75 \
\hline \text { Pulmonary artery (PA) } & 75 \
\hline \text { Pulmonary veir (PV) } & 75 \
\hline \text { Left ventricle (LV) } & 95 \
\hline \text { Aorta } ( \mathrm { A } ) & 95 \
\hline
\end{array}$$ $$\begin{array} { l l l l l l l } 
& \text { RA } & \text { RV } & \text { PA } & \text { PV } & \text { LV } & \text { A } \
& ( \% ) & ( \% ) & ( \% ) & ( \% ) & ( \% ) & ( \% ) \
\hline \text { A } & 75 & 80 & 80 & 95 & 95 & 95 \
\text { B } & 80 & 80 & 80 & 95 & 95 & 95 \
\text { C } & 75 & 75 & 80 & 95 & 95 & 95 \
\text { D } & 75 & 75 & 75 & 95 & 80 & 80 \
\text { E } & 75 & 75 & 75 & 95 & 95 & 95
\end{array}$$

Accepted Answer

A)  $\begin{array} { l l l l l l } 
75 & 80 & 80 & 95 & 95 & 95
\end{array}$ 
B)  $\begin{array} { l l l l l l } 
80 & 80 & 80 & 95 & 95 & 95
\end{array}$ 
C)  $\begin{array} { l l l l l l } 
75 & 75 & 80 & 95 & 95 & 95
\end{array}$ 
D) $\begin{array} { l l l l l l } 
75 & 75 & 75 & 95 & 80 & 80
\end{array}$ 
E)  $\begin{array} { l l l l l l } 
75 & 75 & 75 & 95 & 95 & 95
\end{array}$

Question 3

A 30-year-old woman in her first trimester of pregnancy complains of easy fatigability, heat intolerance, and palpitations. Physical examination shows a slightly enlarged, nontender thyroid gland. Thyroid function studies show an increased total serum thyroxine (T4) level, but normal serum thyroid-stimulating hormone (TSH) levels. Which of the following best explains the results of these studies?

Accepted Answer

A)  Decreased thyroid-binding globulin (TBG) 
B)  Increased synthesis of T4 
C)  Increased synthesis of triiodothyronine (T3) 
D)  Thyroiditis-induced release of T4 
E)  Normal finding in pregnancy

Question 4

Which of the following statements best describes ARDS (acute respiratory distress syndrome)?

Accepted Answer

A)  It occurs only in adults. 
B)  It is best described as a diffuse pulmonary process with decreased thickness of the pulmonary membrane. 
C)  A direct pulmonary insult is required for ARDS to develop. 
D)  Hypercarbia is the most common finding in the early stages of ARDS. 
E)  Mortality rate has been decreasing over the past 5 years.

Question 5

Suppose the plasma membrane of a particular mammalian cell is much more permeable to water and urea than to any other solute. The water permeability is higher than the urea permeability. The cell is initially in a normal physiological saline solution and then is suddenly moved into a solution consisting of 600 mM urea as the only solute. The cell will:

Accepted Answer

A)  Swell initially and continue to swell until lysis 
B)  Swell initially until it reaches osmotic equilibrium with the medium 
C)  Shrink initially and then swell until lysis 
D)  Shrink initially and stay shrunken 
E)  Swell initially and then shrink back to normal volume

Question 6

A 56-year-old right-handed woman states that her right hand shakes when she tries to open a door. Her physician does not observe a tremor when the patient's hands are resting in her lap. She further states that she falls frequently, usually to the right side. The most likely cause of these findings is a lesion in the:

Accepted Answer

A)  Left internal capsule 
B)  Left precentral gyrus 
C)  Right caudal medulla 
D)  Right cerebellum 
E)  Right lateral corticospinal tract

Question 7

A 60-year-old man comes to your office complaining of dyspnea (difficult breathing). His laboratory values are as follows: $\begin{array}{|l|l|l|}
\hline& \text {Breathing}& \text {Breathing $ 100 \% $}\
& \text {air}& \text {$\mathrm{O}_{2} \text { for } 7 \text { minutes }$} \
\hline \text { Arterial } \mathrm{PO}_{2}(\mathrm{mmHg}) & 76 & 500 \
\hline \text { Arterial } \mathrm{PCO}_{2}(\mathrm{mmHg}) & 55 & 65 \
\hline \text { Arterial } \mathrm{Hb}(\mathrm{g} / 100 \mathrm{~mL}) & 18 & 18 \
\hline \text { Arterial } \mathrm{O}_{2} \text { saturation (\%) } & 85 & 100 \
\hline \text { Arterial } \mathrm{pH} & 7.35 & 7.20\
\hline
\end{array}$
 Which of the following diagnoses best explains the laboratory test findings?

Accepted Answer

A)  Patent ductus arteriosus 
B)  Patent foramen ovale 
C)  Complete obstruction of the right bronchus 
D)  Thickened alveolar membrane impairing diffusion 
E)  Pulmonary fibrosis restricting lung movement

Question 8

A 50-year-old homeless man with a 30-year history of alcoholism complains of painful lesions on the mucous membranes of his mouth and tongue and has pigmented keratotic scaling lesions on his face and hands. In addition, he is weak, forgetful, and has burning sensations in various parts of the body and diarrhea. A deficiency of which of the following is most likely to account for these findings?

Accepted Answer

A)  Biotin 
B)  Folic acid 
C)  Niacin 
D)  Riboflavin 
E)  Vitamin C

Question 9

If a healthy 70 kg man loses 2 L of sweat while doing yard work and simultaneously drinks 2 L of pure water, which of the following body fluid changes would be expected?

Accepted Answer

A)  An increase in extracellular osmolarity 
B)  An increase in extracellular fluid (ECF) volume 
C)  An increase in intracellular osmolarity 
D)  An increase in intracellular fluid (ICF) volume 
E)  An increase in plasma Na+ concentration

Question 10

Which of the following is correct for male sex differentiation?

Accepted Answer

A)  The male phenotype is determined by the presence of either X or Y chromosomes. 
B)  Stimulation and development of the indifferent gonad is initiated by the sex-determining region of the Y chromosome (SRY) gene. 
C)  The müllerian ducts develop into the male reproductive tract. 
D)  Sertoli cells are stimulated to produce testosterone. 
E)  Testes have descended into the scrotum by 9 weeks' gestation.

Exam 2: Physiology of Cells and Molecules

Two people have the same total body mass (70 kg) but one has a much higher percentage of body fat than the other. They both habitually ingest 2.5 L of water per day. The individual with the higher percentage of fat will have a:

Which of the following statements best describes ARDS (acute respiratory distress syndrome) ?

If a healthy 70 kg man loses 2 L of sweat while doing yard work and simultaneously drinks 2 L of pure water, which of the following body fluid changes would be expected?

Which of the following is correct for male sex differentiation?