HBY 531 MEDICAL PHYSIOLOGY

LECTURE EXAM 2

2004

 

  

Section 1:  Answer the following using:

 

a = becomes more negative

b = remains the same

c = becomes more positive

 

 

1.  The maximum diastolic potential in a ventricular myocyte ______ when external [K+] is decreased from 8 to 3 mM.  (A)

2.  The maximum diastolic potential in a Purkinje fiber _______ when the external [K+] is lowered from 5 to 1 mM.  (C)

3.  The maximum diastolic potential in the sinus node ______ when the vagus nerve is stimulated. (A)

 

Section 2:  Answer the following using:

a = increases

b = remains unchanged

c = decreases

4.  The slope of the diastolic depolarization in the Purkinje fiber ­­______ when a beta agonist is added to the bathing solution. (A)

5.  The duration of the absolute refractory period in a Purkinje fiber ______ if the plateau duration increases by 50 msec.  (A)

6.  The intracellular [cAMP] in the SA node ______ during vagal stimulation. (C)

7.  The R-R interval of the EKG ______ when the vagus nerve is stimulated. (A)

 

8.  The magnitude of the funny current (if) __________ when the vagus nerve is stimulated.  (C)

9.  The duration of systole ________ following infusion of dobutamine (b1 agonist) into the coronary circulation. (C)

 

10.  Heart rate _______ following infusion of atropine (non-specific muscarinic antagonist) into the coronary circulation. (A)

 

11.  Assuming no change in cardiac output, central venous pressure _________ following the development of hypervolemia in mild cases of congestive heart failure. (A)

 

12.  Assuming no change in cardiac output, central venous pressure _________ following a decrease in arterial vascular resistance. (A)

 

13.  Vascular smooth muscle tone _______ following an increase in Cl- conductance across the membranes of smooth muscle cells. (A)

           

14.  Shear rate __________ as the velocity of blood flow decreases. (C)

           

15.  Vascular resistance _______ in cerebral blood vessels following hyperventilation. (A)

           

16.  Venous return to the right atrium _____ following venoconstriction of splanchnic veins. (A)

           

17.  Total peripheral resistance ________ following an infusion of a therapeutic dose of epinephrine. (C)

           

18.  A young man who was previously well was admitted to the emergency room with barbiturate poisoning that caused severe hypoventilation.  During administration of 100% oxygen to breathe, his arterial PCO2 __________. (B)

 

19.  Within zone 2 of the upright lung, the pressure difference responsible for blood flow _________ with distance toward the base of the lung. (A)

 

20.  When a bronchodilator is administered to a patient with asthma during an attack, the FEV1/FVC _______________. (A)

 

21.  At low lung volumes, expiratory flow (as measured on an expiratory flow-volume curve) __________with increasing expiratory effort. (B)

 

22.  During an operation, the arterial PCO2 of an anesthetized patient is monitored.  The patient is being ventilated by a mechanical ventilator, and the initial value is normal (PCO2 = 40 mmHg).  When the tidal volume is increased by 200 mL, PCO2 __________. (C)

 

 

 

 

Section 3:  For each of the following, choose the single best response.

 

 

Questions 23-26:  The following data show two pressure-volume loops obtained from the same experimental subject who is normal and healthy.  The solid curve (loop 1) was obtained at rest, while the dashed curve (loop 2) was also obtained at rest, but following an intravenous infusion of 1 L of saline.


 

 

 


23.  During which interval in loop 1 is the aortic valve open? (C)

a.  d ® a

b.  a ® b

c.  b ® c

d.  c ® d

e.  b ® d

 

24.  With regard to the venous pulse corresponding to loop 1, the peak of the v-wave occurs closest to:  (A)

a.  point d

b.  point a

c.  point b

d.  point c

e.  the midpoint between points b and c

 

25.  The velocity of shortening within the left ventricle is greatest over the interval between: (B)

a.  b ® c

b.  b’® c’

c.  a ® b

d.  a’ ® b’

e.  d’ ® a’

 

26.  Stroke work: (B)

a.   is greater in loop 1 than loop 2

b.   is greater in loop 2 than loop 1

c.   is equal between the two loops

d.   cannot be determined from these two pressure-volume loops

 

27.  Following activation of b1 receptors on ventricular myocytes, all of the following would be expected to increase except: (D)

a.   the rate of pressure increase (i.e., dP/dt)

b.  peak systolic pressure within the left ventricle

c.  ejection fraction

d.  end systolic volume

e.  stroke work

 

28.  In a vascular bed in which the arterioles demonstrate pressure autoregulation, a decrease in perfusion pressure will result in: (C)

a.   an increase in nitric oxide release by endothelial cells of the arteriole

b.   an increase in cytosolic Ca2+ within vascular smooth muscle cells of the arteriole

c.   vasodilation of the arteriole

d.   an increase in vascular resistance

e.   both b and d

 

29.  An investigator wishes to quantify the rate of uptake of drug X into a particular skeletal muscle.  He obtains blood samples from the artery and vein associated with that muscle and determines that:

 

            [X]artery = 75 mg/100mL

            [X]vein = 50 mg/100mL

            blood flow = 80 mL/min

 

The rate of uptake of drug X into this skeletal muscle is closest to: (B)

a.   0.31 mg/min

b.   20 mg/min

c.   320 mg/min

d.   2000 mg/min

e.   There is not enough information to calculate the rate of uptake

 

30.  Which of the following conditions will favor interstitial fluid shifts into systemic capillaries? (A)

a.   arteriolar vasoconstriction

b.   a decrease in plasma oncotic pressure

c.   hypertension

d.   right heart failure

e.   none of the above

 

31.  During exercise, which of the following is expected to decrease? (B)

a.   heart rate

b.   total peripheral resistance

c.   stroke work

d.   O2 consumption

e.   none of the above will decrease

 

32. Concerning airflow in the lung, (B)

      a.   Flow is more likely to be turbulent in small airways than in the trachea

      b.   In pure laminar flow, halving the radius of the airway increases its resistance sixteen-fold

      c.   The higher the Reynolds number, the less likely is turbulence to occur

      d.   For inspiration to occur, pressure at the mouth must be less than alveolar pressure

      e.   For expiration to occur, intrapleural pressure must fall (become more negative)

 

33. During resting conditions, for normal expiration to occur, (B)

a.   The alveoli must actively contract

b.   The alveolar pressure must be greater than atmospheric pressure

c.   The diaphragm must forcefully contract

d.   The pressure inside the pulmonary capillaries must fall

e.   There needs to be increased sympathetic stimulation of bronchial smooth muscle

 

34.   Some newborn infants lack pulmonary surfactant; therefore,  (A)

      a.   Their lungs are difficult to inflate

      b.   Their work of breathing is reduced due to increased surface tension forces

      c.   Their lungs are over-inflated

      d.   Their lung compliance is increased

      e.   Their respiratory muscles atrophy

 

35.  Which of the following cannot be measured with a simple spirometer and a stopwatch? (C)

      a.   Tidal volume

      b.   Vital capacity

      c.   Residual volume

d.      FEV1

e.       Breathing frequency

 

 

36. Which patient has the highest alveolar ventilation? (D)

      a.   Tidal volume = 1000 ml; Frequency = 6 breaths/min; Dead space volume = 200 ml

      b.   Tidal volume = 500 ml; Frequency = 16 breaths/min; Dead space volume = 200 ml

      c.   Tidal volume = 350 ml; Frequency = 24 breaths/min; Dead space volume = 150 ml

      d.   Alveolar ventilation is the same in all cases

 

37.  You plan to climb Mt. Everest (PB = 247 mmHg) but you want to have the same PO2 in moist inspired gas on the summit as at sea level.  What does the O2 concentration of the inspired gas (in %) need to be? [Assume the inspired air is saturated with H2O](D)

      a.   33

      b.   55

      c.   67

      d.   75

      e.   86

 

38.  If a climber on the summit of Mt. Everest (PB = 247 mmHg) maintains an alveolar PO2 of 37 mmHg and is in a steady state (R=1.0), his alveolar PCO2 cannot be any higher than: [Assume the inspired air is saturated with H2O] (E)

      a.   15 mmHg

      b.   12 mmHg

      c.   10 mmHg

      d.   8 mmHg

      e.   5 mmHg

 

39.  Which of the following is not true regarding the pulmonary circulation as compared to the systemic circulation? (D)

      a.   Pulmonary arterial vessels have lower intravasclar pressures than those found in systemic arteries

      b.   Pulmonary arterial vessels have thinner walls and greater internal diameters than corresponding branches of the systemic vessels

      c.   Pulmonary circulation has the same blood flow per minute

      d.   Pulmonary vascular resistance is approximately tenfold greater

 

40. When a patient’s lungs are inflated by positive pressure using a mechanical ventilator, (C)

      a.   The caliber of the extra-alveolar vessels decreases

      b.   The caliber of the pulmonary capillaries is increased

      c.   The likelihood of zone 1 conditions occurring is increased

      d.   Pulmonary vascular resistance decreases

      e.   c and d

 

 

 

41.  Factors that might lead to a diffusion limitation of oxygen transfer across the blood-gas barrier include: (E)

      a.   Exercise

      b.   High cardiac output

      c.   Pulmonary fibrosis

      d.   Breathing a 50% oxygen mixture

      e.   a, b, and c

 

42.  An increase in which of the following shifts the hemoglobin-oxygen dissociation curve to the left? (A)

      a.   Oxygen affinity of hemoglobin

      b.   H+ concentration

      c.   PCO2

      d.   Temperature

      e.   2,3-DPG concentration

 

43. In peripheral capillaries, (B)

      a.   CO2 loading is similar to that seen in the lungs

      b.   More CO2 can be loaded into the blood because PO2 is reduced

      c.   More O2 can be unloaded from the blood when PCO2 is low

      d.   More O2 can be unloaded from the blood when pH is increased

      e.   O2 unloading is similar to that seen in the lungs

 

44.  A patient was admitted to the hospital with an acute exacerbation of COPD.  When given 100% O2, his arterial PCO2 increased from 60 to 85 mmHg.  The most likely causative factor was:  (B)

      a.   Increased in airway resistance

      b.   Depression of ventilation

      c.   Hypoxic pulmonary vasoconstriction in poorly ventilated areas of the lung

      d.   Reduced levels of 2,3-DPG in the blood

      e.   Depression of cardiac output

 

45. During exercise of progressive intensity, (A)

      a.   Minute ventilation and CO2 production rise sharply at “anaerobic threshold”

      b.   Increased minute ventilation reduces PCO2 levels

      c.   Oxygen consumption decreases slightly

      d.   Blood lactate levels remain constant

      e.   a and d

 

 

 

 

 

 

 

 

46.  Which of the following statements is FALSE? (B)

a.   Increased renal sympathetic nerve activity will increase afferent arteriolar resistance.

b.   A rise in the systemic plasma [protein] will tend to increase net filtration pressure in the glomerulus.

c.   Dilation of the efferent arteriole will tend to reduce filtration fraction.

d.   A rise in filtration fraction will increase the net rate of proximal tubular Na+ reabsorption

 

47.  Which of the following characteristics of the glomerular capillary wall is TRUE? (C)

a.   It consists of 2 distinct layers:  a basement membrane and a layer of epithelial cells called podocytes.

b.   Its permselectivity properties with respect to plasma proteins are determined primarily by the fenestrations in the capillary endothelium. 

c.   It is freely permeable to uncharged solutes with MW’s less than approximately 5 kD.

d.   Large anionic solutes are more permeable than cationic solutes of the same effective molecular radius.

 

48.  Which of the following statements about autoregulation of RBF and GFR is FALSE?   (B)

a.   Autoregulation is mediated, in part, by a myogenic reflex intrinsic to vascular smooth muscle.

b.   An important autoregulatory mechanism involves the effect in which increased GFR will result in a substantially increased tubular pressure.

c.   Tubuloglomerular feedback contributes to renal autoregulation by increasing afferent arteriolar resistance when GFR increases and the flow of tubular fluid through Henle’s loop rises.

d.   Renal autoregulation does not prevent changes in RBF in response to vasoactive hormones. 

 

49.  Which of the following statements about reabsorption in the second half of the proximal tubule is FALSE? (D)

a.   The transport of sodium and chloride into the cells involves the cycling of organic bases across the apical membrane.

b.   By the time the tubular fluid leaves this segment and enters Henle’s loop, tubular fluid flow has been reduced to about 1/3 of the flow entering the proximal tubule from Bowman’s space.

c.   The chloride ion concentration in this segment is higher than in arterial plasma, owing to the preferential reabsorption of bicarbonate in the first part of the proximal tubule. 

d.   There is no passive diffusion of ions through the tight junctions

 

 

 

50.  Which of the following mechanisms is not significantly involved in sodium reabsorption in the principal cells in the late distal tubules and collecting ducts? (C)

a.   Passive sodium diffusion through apical membrane sodium channels

b.   Active extrusion of sodium from the cell via Na,K-ATPase located in the basolateral membrane

c.   Passive sodium diffusion through the tight junctions

d.   There is variable expression of apical membrane cation channels, a process controlled by aldosterone.

 

51.  Which of the following transport characteristics are shared by thick ascending limb cells and the cells of the early distal tubule? (D)

a.   Both are impermeable to water

b.   Both reabsorb sodium and chloride ions

c.   Both act to reduce the osmolarity of the tubular fluid

d.   All of the above are correct.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

52.  Using the information on the graph shown above, what can you conclude about the renal handling of this freely filtered substance? (B)

a.   it is subjected to net secretion with a Tm of 300 mg/min.

b.   it is subjected to net reabsorption with a Tm of 300 mg/min. 

c.   it is subjected to net reabsorption with a Tm of 3 mg/mL.

d.   it is subjected to net secretion, but the transport is not Tm limited.

 

53.  A person is infused with PAH and, after equilibration, PPAH is 0.02 mg/mL.    At this time, urine flow is 2 mL/min and UPAH is 3 mg/mL.  What is renal plasma flow? (B)

a.   200 mL/min

b.   300 mL/min

c.   500 mL/min

d.   1000 mL/min

 

 

54.  Which of the following statements is FALSE? (B)

a.   A rise in plasma ADH levels will not influence proximal tubular water reabsorption.

b.   A 2% reduction in blood volume will increase ADH secretion.

c.   A rise in plasma osmolarity will lead to an increase in the water permeability of apical membranes in principle cells in the collecting ducts.

d.   Inhibition of ADH action will reduce urea reabsorption in inner medullary collecting ducts.

 

55.  Which of the following statements about renal medullary countercurrent multiplication is FALSE? (C)

a.   The high concentrations of sodium and chloride in the medullary interstitium result from the reabsorption of theses ions by the cells of the ascending limb of Henle’s loop.

b.   Countercurrent multiplication does not occur in the vasa recta.

c.   Urea is passively secreted into the tubular fluid along the entire length of the ascending limb of Henle’s loop.

d.   When ADH levels are low, the low osmolarity of the excreted urine is the result of the transport processes in the ascending limb of Henle’s loop.

 

56.  Which of the following statements is FALSE? (A)

a.   An increase in tubular fluid flow in the thick ascending limb will tend to increase renin secretion.

b.   Inhibition of angiotensin converting enzyme will tend to reduce proximal tubular sodium reabsorption.

c.   Increasing dietary sodium intake from a low to a high level will reduce  plasma [aldosterone].

d.   An increase in plasma angiotensin II concentration will decrease the renal renin secretion rate.

 

57.  Which of the following events would not occur as a result of doubling sodium chloride intake in a healthy person with free access to water.   (A)

a.   a 25% rise in plasma sodium concentration

b.   a modest gain in body weight

c.   an increase in extracellular fluid volume

d.   a reduction in plasma renin levels

 

58.  Which of the following is not an action of atrial natriuretic peptide?  (C)

a.   inhibition of ADH secretion

b.   inhibition of renin secretion

c.   constriction of the afferent arteriole

d.   inhibition of inner medullary collecting duct sodium reabsorption

 

 

 

59.  Which of the following statements about potassium transport in principal cells is FALSE? (B)

a.   High tubular fluid potassium concentrations will retard passive potassium diffusion through potassium channels in the apical membrane.

b.   Potassium secretion will tend to fall when tubular fluid flow rate increases.

c.   Aldosterone stimulates both potassium secretion and sodium reabsorption.

d.   A rise in plasma potassium concentration will increase potassium secretion even when aldosterone levels are constant.

 

60.  Which of the following statements about renal epithelial H+ secretion is FALSE? (D)

a.   H+ secretion will rise when either plasma bicarbonate concentration falls or plasma PCO2 rises.

b.   H+ secretion in the proximal tubule occurs via both a Na+-H+ antiporter and an H+-ATPase.

c.   H+ secretion into the lumen of the proximal tubule reduces the tubular fluid bicarbonate concentration.

d.   A relatively small fraction of the secreted protons are buffered in the tubular fluid.

 

61.  A person has a plasma pH of 7.53,  plasma bicarbonate concentration of 40 mM, and arterial PCO2 of 50 mmHg.  How would you describe the acid base status of this person? (C)

a.   respiratory alkalosis

b.   respiratory acidosis

c.   metabolic alkalosis

d.   metabolic acidosis

 

 

62.  Which of the following statements is FALSE? (A)

a.   Intravenous infusion of HCl will reduce renal production of NH3 from glutamine.

b.   Intravenous infusion of NaOH will suppress proximal tubular bicarbonate reabsorption.

c.   Respiratory compensation for a metabolic acidosis involves increased alveolar ventilation.

d.   Inhibition of renal carbonic anhydrase will reduce the ability of the kidney to excrete acid.

 

63.  A person has a urine flow of 1.5 liters/day, and urinary concentrations of ammonium, titratable acid, and bicarbonate of 5, 6, and 1 mM, respectively.  What is the net rate of renal acid excretion? (A)

a.   15 mmoles/day

b.   18 mmoles/day

c.   11 mmoles/day

d.   60 mmoles/day

 

 

Section 4:  This section contains 3 different cases that refer to cardiovascular, respiratory, and renal physiology.  Each case is followed by several questions.  There are also some clinically based renal questions.  For each of the following questions, choose the single best response.

 

Clinical Case Study 1:  A 38-year man complains of moderate dyspnea at rest that increases in intensity with the onset of exercise.  He also experiences transient numbness and weakness in his legs.  Patient reveals that he had rheumatic fever as an adolescent.  Upon physical exam, you note a low frequency diastolic murmur of the decresendo type and upon ausculation of the lungs you detect rales.  A pressure-volume loop from this patient (dotted curve) is shown below in comparison with a normal pressure volume loop (solid curve):


 

 

 


64.  Which of the following pressures would be expected to be elevated in this patient? (D)

  1. mean arterial pressure within the aorta
  2. peak systolic pressure within the left ventricle
  3. arterial pulse pressure
  4. left atrial pressure
  5. both a and b

 

65.  Which compensatory change is most likely to occur in this patient? (C)

a.  concentric left ventricular hypertrophy

b.  eccentric left ventricular hypertrophy

c.  right ventricular hypertrophy

d.  dilation of the aorta

e.  fusion of aortic valve leaflets

 

66.  The most likely diagnosis to explain this patient’s signs and symptoms is: (C)

a.   aortic stenosis

b.   aortic regurgitation

c.   mitral stenosis

d.   mitral regurgitation

e.   congestive heart failure

 

67.  Which of the following drugs would be expected to have the greatest effect at reducing the numbness and weakness in this patient’s legs? (E)

a.   Sildenafil (i.e., VIAGRA) – a cGMP phosphodiesterase inhibitor

b.   Digoxin – a cardiac glycoside

c.   Dobutamine – a b1 agonist

d.   Captopril – an ACE inhibitor

e.   Warfarin – an oral anticoagulant

 

 

 

Clinical Case Study 2:  A 44-year old man presents with symptoms of dyspnea, chest pains, and fatigue and weakness, all of which increase upon exertion.  From his history, you learn that 9 months ago, he experienced a myocardial infarction localized to his left ventricle due to coronary artery disease, which was corrected at that time with by-pass surgery.  Since then, his symptoms have developed progressively.  Upon physical exam, you note his respiration and heart rates are elevated, his skin is pale, and his jugular veins are distended.  Upon auscultation of the lungs, you detect rales, and you detect a third heart sound.  A pressure-volume loop from this patient (dotted curve), taken shortly after his myocardical infarction, is shown below in comparison with a normal pressure volume loop (solid curve).  Assume that the patient’s pressure-volume loop represents the uncompensated status of this patient.


 


68.  The most likely diagnosis that explains this patient’s signs and symptoms is: (D)

a.   aortic stenosis

b.   mitral stenosis

c.   mitral regurgitation

d.   chronic heart failure due to systolic dysfunction of the left ventricle

e.   chronic heart failure due to diastolic dysfunction of the left ventricle

 

69.  Prior to compensation, which of the following would be expected to be significantly reduced in this patient? (B)

a.   peak systolic pressure

b.   stroke volume

c.   end-diastolic pressure

d.   end systolic volume

e.   all of the above

 

70.  Following compensation, the pressure-volume loop of this patient (not shown) would indicate all of the following except: (C)

a.   an increase in ejection fraction compared to pre-compensation

b.   an increase in stroke volume compared to pre-compensation

c.   a decrease in end systolic and end diastolic volumes compared to pre-compensation.

d.   an upward shift in the isovolumetric pressure volume relationship compared to pre-compensation

e.   an increase in stroke work compared to pre-compensation.

 

71.  Following compensation, all of the following would be elevated compared to normal except: (accept all)

a.   the action potential frequency arriving at the NTS from baroreceptor nerves

b.   total peripheral resistance

c.   plasma angiotensin II levels

d.   plasma aldosterone levels

e.   plasma ADH levels

 

 

Clinical Case 3: 

 

History:    A 60 year old male is seen in consultation for shortness of breath.  He was reasonably well until about 15 years ago when he began to notice that he had to pause to catch his breath after climbing a flight of stairs.  Now he finds that he needs to stop after walking about half a block on level ground.  He has had a chronic cough for about 15 years, and on several occasions each year, particularly in the winter, he has coughed up yellow, purulent sputum.  He started smoking cigarettes when he was 15 years old, and for most of his life he has smoked two packs a day.  During the past 12 months, he has noted intermittent swelling of his ankles associated with exacerbations of respiratory infections.  There is no family history of lung disease.

 

Physical Examination:

1.   The patient was dyspneic and somewhat florid in appearance with central cyanosis.

2.   His temperature was 38 OC; his blood pressure was 150/80; his heart rate was 80 beats/min.

3.   There was slight neck vein engorgement.

4.   The chest appeared over-inflated and barrel-shaped, and a chest x-ray showed overinflation.

5.   Auscultation of the chest revealed a generalized decrease in intensity of breath sounds.  Occasional rhonchi (whistling sounds) were heard over both lungs.

6.   Hemoglobin concentration was 17 g/dL

7.   Right heart catheterization revealed that mean pulmonary artery pressure was 30 mmHg; pulmonary artery wedge pressure was normal.

8.   The following results were obtained during pulmonary function testing:

                                                Observed                        Predicted

            VC                                  3.3 L                             4.8 L

            FRC (helium dilution)       6.0 L                             3.7 L

            TLC                                8.1 L                             7.1 L

            Compliance                     0.35 L/cm H2O              0.20 L/cm H2O

 

            FEV1                               1.3 L                             3.6 L

            FVC                               3.1 L                             4.8 L

            FEV1/FVC                      42%                              75%

 

            PO2                                 58 mmHg                       85 mmHg

            PCO2                              49 mmHg                       50 mmHg

            pH                                  7.36                               7.40

 

 

 

72. The patient’s history and pulmonary function test results are consistent with:  (A)

      a.   Chronic bronchitis and emphysema (COPD)

      b.   Emphysema in the absence of chronic bronchitis

      c.   Asthma

      d.   Pulmonary fibrosis

      e.   Pulmonary edema

 

73. Which of the following factors may reduce the FEV1 in this patient? (C)

      a.   Reduced strength of diaphragmatic contraction

      b.   Increased radial traction on the airways

      c.   Increased resistance of the small airways because some have been destroyed

      d.   Increased elastic recoil in the lung

      e.   All of the above factors may contribute to reduced FEV1

 

 

 

 

74. Compliance (E)

      a.   Is increased in this patient because elastic recoil in the lung is reduced

      b.   Is determined by the slope between two points on the pressure-volume curve

c. Is defined as the change in lung volume divided by the change in the transpulmonary pressure

d.  Can be determined in a patient by using esophageal pressure as a measure of intrapleural pressure

e.  All of the above

 

75. During cough, (E)

      a.   Intrapleural pressure becomes more negative

      b.   Transpulmonary pressure increases

      c.   The velocity of airflow increases leading to turbulence

      d.   Airways resistance is increased due to dynamic compression of the airways

      e.   c and d

 

76. Severe arterial hypoxemia in this patient is most likely caused by: (D)

      a.   Hypoventilation

      b.   Diffusion impairment

      c.   Shunt

      d.   Ventilation-perfusion inequality

 

 

Renal Clinical Questions:

 

77.  Which of the following symptoms WOULD NOT be expected in a person with unilateral renal artery stenosis?  (A)

a.   Low renin and angiotensin II levels

b.   Elevated plasma creatinine concentrations

c.   Significant differences in kidney size.

d.   Displays shift of the salt-loading renal function curve to the right (higher pressure).

 

78.  Which of the following statements concerning elevated urinary plasma protein excretion is FALSE?   (C)

a.   It can lead to hypoproteinemia and peripheral edema. 

b.   It can result in a reduction in effective circulating volume.

c.   It will lead to a reduction in extracellular fluid volume.

d.   It indicates the possibility of glomerular capillary injury.

 

 

 

 

 

 

 

79.  Which of the following statements concerning chronic renal failure is FALSE? (C)

a.   The loss of functioning nephrons induces a compensatory elevation in GFR in the remaining nephrons. 

b.   Enlargement of the glomerular capillaries contributes to a rise in stress in the capillary wall.

c.   Hyperkalemia develops and this is just a consequence of buffering of H+ by cytosolic proteins.

d.   Salt-sensitive hypertension often develops as renal function declines. 

 

80.  Extracellular volume (ECV) depletion in a person taking large doses of non-steroidal anti-inflammatory drugs (NSAID, i.e., aspirin, ibuprofin, etc.) can cause ischemic acute renal failure.  Which of following factors IS NOT INVOLVED in the pathogenesis of the renal vasoconstriction? (B)

a.   Renin and angiontensin II levels are elevated secondary to the ECV depletion.

b.   Endothelial NO production is inhibited by NSAIDs, resulting in a constriction of the afferent arteiole.  

c.   Renin secretion increases to high levels because of a marked fall in the intravascular pressure sensed by the renal baroreceptor.

d.   Prostaglandin production by the renal vasculature is reduced.