HBY 531 Organ Systems
Mid-Term Examination 1996
Section 1: Answer the following using:
A = becomes more negative
B = remains unchanged
C = becomes more positive
1. The potassium equilibrium potential __________ when the extracellular [K+] is reduced from 5mM to 2mM.
2. The maxmium diastolic potential of the Purkinje fiber __________ when the extracellular [K+] is reduced from 4mM to 0.5mM.
3. The overshoot of the Purkinje fiber action potential __________ when half the extracellular chloride is replaced with an impermeant substitute.
4. The overshoot of the sinus node action potential __________ when 1uM tetrodotoxin is added to the bathing solution.
Section 2: Answer the following using:
A = increases
B = no change, or remains unchanged
C = decreases
5. The duration of the T-wave __________ when the duration of the endocardial action potential increases by 50msec.
6. The slope of the diastolic depolarization in the Purkinje fiber __________ when the vagus is stimulated in the absence of sympathetic stimulation.
7. The duration of the QRS complex __________ if the serum [K+] increases from 4mM to 8mM.
8. The duration of the T wave __________ when the conduction velocity in the A-V node is decreased by a factor of two.
9. The slope of the diastolic depolarization in the Purkinje fiber __________ when a beta agonist is added to the bathing solution.
10. In a patient with severe emphysema, total lung volume __________.
11. Compared to control values, asthma results in __________ in residual volume.
12. During expiration, alveolar pressure __________ relative to atmospheric pressure.
13. Destruction of the glossopharyngeal nerve will result in __________ in the oxygen sensing by the aortic bodies.
14. During an extended stay at high altitude, the pH of the CSF __________ relative to that of the pH of the blood.
15. Under normal conditions, as cardiac output increases, blood flow in the apices of the lungs __________.
16. The diffusing capacity of a gas in the lung increases as its solubility __________.
17. Significant embolization of the lung will result in __________ in the physiological deadspace.
18. Boyles Law, as it applies to the lung, simply states that as the volume of a closed container decreases, the pressure of the contained gases __________.
19. As systemic blood pressure increases, the resistance of the afferent glomerular arteriole __________.
20. An increase in the systemic plasma oncotic pressure will result in __________ in the GFR.
21. Constriction of the afferent glomerular arteriole will result in __________ in the glomerular capillary hydrostatic pressure.
22. A fall in the plasma [angiotensin II] causes __________ in proximal tubule sodium reabsorption.
23. A decrease in the filtration fraction results in __________ in the net proximal tubular sodium and water reabsorption.
24. As plasma [ADH] increases, water permeability in the proximal tubule __________.
25. As the filtered load of glucose increases, sodium entry into proximal tubular cells __________.
26. Decreased apical membrane Na+ permeability in collecting ducts will cause __________ in Na+ reabsorption in collecting ducts.
27. As plasma [aldosterone] increases, the apical membrane K+ permeability in the distal tubule __________.
28. Administration of an angiotensin converting enzyme inhibitor (Captopril) will lead to __________ in aldosterone secretion.
29. As plasma [ANP] increases, collecting duct sodium reabsorption __________.
30. An increase in the plasma [angiotensinogen] will result in __________ in the plasma [angiotensin II].
31. Increases in arterial PCO2 will result in __________ in renal bicarbonate excretion.
32. As the dietary intake of sodium increases in a healthy person, the plasma osmolarity __________.
33. Constrictive stenosis of the renal artery causes __________ in renin secretion.
Section 3: For each of the following statements, choose A if the statement is true, or B if the statement is false.
34. Stroke volume = (End Systolic Volume) - (End Diastolic Volume).
35. Heart rate increases in response to increased force of contraction.
36. A reduction in arterial blood O2 tension stimulates the peripheral chemoreceptors resulting in increased tone of the resistance and capacitance vessels.
37. Decreased blood volume leads to increased heart rate and increased stroke volume.
38. Vasopressin (ADH) is actively secreted by the posterior pituitary gland in response to hemorrhage.
39. Hyperventilation induces dizziness due to decreased oxygen supply to the brain.
40. Stimulation of beta receptors in the heart will lead to an increase in heart rate, but a decrease in contractility.
41. An increase in mean perfusion pressure to a skeletal muscle will lead to a compensatory arteriolar constriction and decreased muscle blood flow.
42. Two functions of angiotensin II that lead to elevated blood pressure include increased aldosterone secretion and arteriolar vasoconstriction.
43. Blood flow through the brain is regulated predominantly by sympathetic vasoconstrictive nerves.
Section 4: For each of the following, choose the single best response.
44. Increasing the pre-load of cardiac muscle will:
a. reduce ventricular end-diastolic volume.
b. reduce the peak tension of the muscle.
c. decrease the initial velocity of shortening.
d. decrease the time it takes the muscle to reach peak tension.
e. increase the ventricular wall tension.
45. The time from the carotid artery volume pulse to the dicrotic notch (incisura) is a measure of the period of:
a. atrial systole.
b. ventricular ejection.
c. reduced ventricular filling.
d. rapid ventricular filling.
e. ventricular isovolumic relaxation.
46. Venous return is enhanced during excercise by all of the following EXCEPT:
a. increased depth of respiration.
b. pumping action of skeletal muscle.
c. venoconstriction.
d. reduced arteriolar resistance.
e. an erect position.
47. An increase in systemic blood pressure leads to which of the following effects?
a. An increase in the velocity at which blood is ejected from the left ventricle.
b. An increase in cardiac output.
c. An increase in the residual volume of blood in the left ventricle.
d. A decrease in the time it takes for the left ventricular wall to develop peak pressure.
e. A decrease in the maximal wall tension developed in the left ventricular muscle.
48. During diastole, blood flow into the ventricles sometimes produces:
a. a first heart sound.
b. a second heart sound.
c. a third heart sound.
d. a fourth heart sound.
e. an ejection click.
49. Stimulation of the baroreceptors by increased blood pressure is associated with:
a. an increase in cardiac contractility.
b. an increase in heart rate.
c. an increase in the discharge rate of the vagus efferent cardiac neuron.
d. a decrease in systemic blood pressure.
e. none of the above.
Illustrated above is a left ventricular pressure-volume loop from a normal healthy adult. Four different points are indicated by letters W through Z. Use these data to answer the next three questions (Questions 50-52).
50. The part of the cardiac cycle described as iso-volumetric relaxation is between points:
a. W and X.
b. X and Y.
c. Y and Z.
d. Z and W.
51. The part of the cardiac cycle that has the highest rate of energy consumption (highest rate of ATP hydrolysis) is between points:
a. W and X.
b. X and Y.
c. Y and Z.
d. Z and W.
52. The part of the cardiac cycle that does the most physical work (external work as force acting through distance) is between points:
a. W and X.
b. X and Y.
c. Y and Z.
d. Z and W.
Illustrated above are simultaneous changes in left ventricular pressure (LV pressure) and volume (LV volume) over time. There are nine points on the LV pressure curve (points A through I). Use these data to answer the following three questions (Questions 53-55).
53. The beginning of the second heart sound (S2) is indicated by point:
a. C
b. D
c. F
d. G
e. I
54. The point at which the aortic valve closes is indicated by point:
a. C
b. D
c. F
d. G
e. I
55. The end of left ventricular systole is indicated by point:
a. C
b. D
c. F
d. G
e. I
56. With regard to blood vessel compliance, which of the following statements is TRUE?
a. Compliance relates change in volume to change in pressure.
b. Compliance relates change in resistance to change in pressure.
c. Compliance typically increases with age.
d. Compliance of arteries is greater than that of veins.
57. Factors that would lead to decreased turbulence in a blood vessel would not include:
a. high blood viscosity.
b. small vessel diameter.
c. high vessel compliance.
d. low velocity of blood flow.
58. Poiseulle's Law states that blood flow is:
a. directly proportional to the (radius)2.
b. directly proportional to the length.
c. inversely proportional to the blood viscosity.
d. all of the above.
59. Norepinephrine is:
a. an alpha-antagonist that mediates increases in heart rate at the sino-atrial node.
b. an alpha-agonist that causes an upward and leftward shift in the cardiac function curve (cardiac output vs. central venous pressure).
c. a beta-antagonist that mediates an increased peripheral resistance in response to hemorrhage.
d. a beta-agonist that increases peripheral resistance and increased heart rate.
60. Which of the following would be the best temporal order of mechanisms controlling arterial pressure?
a. baroreceptors - capillary fluid shift - aldosterone - CNS ischemic response.
b. chemoreceptors - (renin-angiotensin II-vasoconstriction) - capillary fluid shift - aldosterone.
c. CNS ischemic response - baroreceptors - capillary fluid shift - aldosterone.
d. renin-angiotensin II-vasoconstriction - capillary fluid shift - aldosterone.
61. Acute blood loss induces which of the following hemodynamic changes?
a. bradycardia
b. hypertension
c. generalized arteriolar vasoconstriction
d. generalized venodilation
e. all of the above
62. Edema caused by abnormal lymph accululation may be caused by:
a. increased capillary pressure.
b. decreased [plasma proteins].
c. increased capillary permeability.
d. decreased lymph return.
e. all of the above.
63. When speaking of Zone IV conditions of flow in the lung,
a. alveolar pressure exceeds arterial and venous pressures.
b. arterial pressures exceed both alveolar and venous pressures.
c. alveolar pressure exceeds venous pressure, but not arterial pressure.
d. arterial pressure exceeds venous pressure, and both exceed alveolar pressure.
e. none of the above.
64. Which of the following substances usually act as bronchodilators?
a. acetylcholine
b. histamine
c. sympathetic stimulation
d. beta antagonist
e. none of the above.
65. Hemoglobin releases oxygen more slowly when the:
a. pH is more acidic.
b. carbon dioxide is elevated.
c. carbaminohemoglobin levels are low.
d. pH is more alkaline.
e. none of the above.
66. Bonnie Blair, the Olympic and World Champion speed skater, has a resting minute ventilation of 7 1iters/minute, a respiratory rate of 12/minute, and a total deadspace of 15%. What is her alveolar ventilation?
a. 7 liters/minute
b. 1.05 liters/minute
c. 5.95 liters/minute
d. 1.5 liters/minute
e. 4.8 liters/minute
67. All of the following can reduce vital capacity EXCEPT:
a. a decreased total lung capacity.
b. an increased residual volume.
c. a weakness of the inspiratory muscles.
d. a weakness of the expiratory muscles.
e. a decreased alveolar surface tension.
68. The volume of gas in the lungs at the end of a normal expiration is referred to as the:
a. residual volume.
b. expiratory reserve volume.
c. functional residual capacity.
d. inspiratory reserve volume.
e. total lung capacity.
69. Arterial PCO2 is increased in a normal individual while:
a. excercising.
b. breathing a gas mixture with a high PO2.
c. ascending a mountain.
d. hypoventilating.
e. scuba diving.
70. If an area of the lung is not ventilated, but blood flow continues, then the blood leaving that area will have a composition equal to:
a. the inspired gas.
b. the normal systemic arterial blood.
c. the composition of blood in the pulmonary artery.
d. the composition of blood in the coronary arteries.
e. an indeterminate value because of an unknown ventilation:perfusion ratio.
71. PCO2 affects respiration primarily by stimulating the:
a. medullary chemoreceptors.
b. carotid and aortic bodies.
c. J receptors.
d. baroreceptors.
e. hypoglossal nerve.
72. What immediately happens if a large hole is made across the chest wall, exposing the intrapleural space to atmospheric pressure (a pneumothorax)?
a. The pleural air will quickly be absorbed into the systemic venous blood.
b. The chest wall will spring out somewhat, but the lung will not collapse.
c. The lung will collapse, but the chest wall will remain in its functional residual capacity position.
d. The lung will collapse expelling air through the mouth and/or nose, but will not be reexpanded by continued spontaneous breathing movements.
e. Rhythmical breathing will abruptly cease and the subject will die from asphyxiation (lack of oxygen).
73. All of the following volume relationships are always true EXCEPT:
a. total lung capacity > inspiratory capacity.
b. residual volume > functional residual capacity.
c. alveolar volume > alveolar dead space volume.
d. physiological dead space volume > anatomical dead space volume.
e. functional residual capacity > expiratory reserve volume.
74. The two most important components contributing to the total work of breathing are:
a. elastic work and flow resistive work.
b. negative inspiratory work and inertial work.
c. inspiratory flow resistive work and viscous resistance work between lobes.
d. elastic work and intertial work.
e. flow resistive work and negative inspiratory work.
75. Intrapleural pressure is always negative EXCEPT:
a. during deep inspiration.
b. during quiet, normal (eupneic) breathing.
c. during forced expiration against a closed glottis (ValSalva).
d. during slow expiration to residual volume.
e. during apnea.
76. Normally, red blood cells passing through the lungs:
a. swell in volume because of an increased intracellular osmotic pressure.
b. process bicarbonate ions back into CO2 for diffusion to the alveolar spaces.
c. easily fit side-by-side through the much larger diameter pulmonary capillaries.
d. pick up O2 molecules which bind to hemoglobin by oxidizing ferrous sites to the ferric state.
e. experience a left shift in the CO2 dissociation curve due to the high O2 partial pressure.
77. At total lung capacity:
a. the lung is stretched out above its equilibrium volume and the chest wall is compressed in below its equilibrium volume.
b. the lung is compressed in below its equilibrium volume and the chest wall is compressed in below its equilibrium volume.
c. the lung is stretched out above its equilibrium volume and the chest wall is stretched out above its equilibrium volume.
d. the lung is stretched out above it equilibrium volume and the chest wall is at its equilibrium volume.
e. the lung is at its equilibrium volume and the chest wall is compressed in below its equilibrium volume.
78. Which one of the following statements regarding resistance to airflow is TRUE?
a. Resistance is directly proportional to radius raised to the fourth power.
b. For a given tube size (length and radius) and pressure gradient, laminar flow profiles have a lower resistance than non-laminar flow profiles.
c. On a percent basis, nasal air passages offer little resistance to breathing.
d. Airway resistance increases with increases in lung volume.
e. Dynamic compression of the airways decreases the resistance to forced expiratory airflow.
79. In respiratory acidosis, which of the following statements is FALSE?
a. The kidneys will compensate for the low pH by increasing plasma [bicarbonate].
b. Hydrogen ion secretion by the renal tubular cells will rise.
c. The major buffer for the excess hydrogen ions in plasma is bicarbonate.
d. Plasma [K+] may be slightly elevated, owing to exchange of intracellular K+ with H+.
80. In regards to the composition of plasma, which of the following is FALSE?
a. Plasma sodium concentration will rise markedly when dietary sodium intake is increased.
b. The concentrations of Na+ and Cl- are major determinant of plasma osmolarity.
c. Plasma osmolarity is monitored by osmoreceptors located in the hypothalamus.
d. Plasma osmolarity can remain relatively constant in the absence of ADH if the thirst mechanism is intact and drinking water is available.
81. Which of the following will NOT OCCUR following a moderate drop in blood volume?
a. Increased filtration fraction.
b. Decreased secretion of atrial natriuretic hormone.
c. Increased aldosterone secretion from the adrenal medulla stimulated by angiotensin II.
d. Decreased sodium and potassium permeabilities of the luminal membrane of collecting duct cells.
82. The renal clearance of a drug was measured and found to be 150 ml/min. In the same person, GFR was 100 ml/min. The drug is freely filtered and not produced or metabolized in the kidney. Given this information, which of the following best describes the transport of this drug by the renal tubules?
a. Net reabsorption.
b. Net secretion.
c. No net tubular transport.
d. There is not enough information to determine how the drug is transported.
83. A man receives an intravenous infusion of inulin. After equilibration, urinary inulin excretion is 1.6 mg/min and plasma [inulin] is 0.02 mg/ml. What is his GFR?
a. 80 ml/min
b. 100 ml/min.
c. 120 mg/min
d. none of the answers are correct.
84. A person has a plasma PCO2 of 35 mmHg and plasma [bicarbonate] of 15 mM. Which of the following is closest to the plasma pH?
a. 6.1
b. 7.35
c. 7.25
d. none of the values are within 0.1 pH units of the correct answer.
85. A person has a plasma pH of 7.32, an arterial PCO2 of 60, and plasma [bicarbonate] of 30 mM. What kind of acid-base disturbance does this person
have?
a. Metabolic Alkalosis
b. Metabolic Acidosis
c. Respiratory Alkalosis
d. Respiratory Acidosis
86. Using the graph above, what is the Tm of the transport process?
a. 2 ug/min
b. 0.0 ug/min
c. 3 ug/min
d. 0.03 ug/ml
87. In the loop of Henle:
a. the reabsorption of sodium by the cells of the ascending limb involves a Na,K,2Cl cotransport system that is located on the basolateral membrane.
b. the fluid leaving the ascending limb has a lower osmolarity than the fluid entering the descending limb.
c. both the ascending and descending limbs have high water permeabilities.
d. the osmolarity of the fluid in the descending limb rises because of active sodium chloride secretion in this segment.
88. Which of the following statements about the medullary urine concentrating mechanism is FALSE?
a. Tubular fluid flow is decreased in the descending limb of Henle's loop by passive osmotic water reabsorption.
b. Treatment with high levels of the drug furosemide, which acts on the thick portion of the ascending limb, will limit the ability of the kidney to generate both hypertonic and hypotonic urine.
c. Urea is secreted in the inner medullary ascending limbs and is reabsorbed in the distal tubule.
d. The process of passive countercurrent exchange results in the cycling of medullary solutes into the descending vasa recta and out of the ascending vasa recta.
89. The automomic input (Pick the INCORRECT answer):
a. to the kidney includes postganglionic fibers which synapse on interlobular arteries, afferent arterioles and efferent arterioles.
b. arising from postganglionic parasympathetic nerves onto smooth muscle cells of bronchioles is mediated by muscarinic receptors on the smooth muscle cells.
c. to the kidney arises from the celiac ganglion
d. of the heart for both sympathetic and parasympathetic is equally distributed throughout the working myocardium.
90. With regard to the automonics:
a. all postganglionic cell bodies/dendrites contain nicotinic receptors.
b. most postganglionic parasympathetic neurons give rise to unmyelinated axons.
c. Many of the cell bodies of neurons within the chain ganglia of T1-T5 are postganglionic cells which innervate the heart and lungs.
d. norepinephrine activates alpha receptors only.