Quiznetik

Physiology | Set 6

1. With regard to chemoreceptors, all of the following are true EXCEPT:

Correct : B. the medullary chemoreceptors respond to blood (H+)

2. In the autonomic nerve system, β antagonism results in:

Correct : E. increased insulin and glucagon secretion

3. The reticular activating system:

Correct : A. has depressed conduction during anaesthesia

4. Which substance is 60 times more concentrated in urine than in plasma?

Correct : D. urea

5. Regarding the anatomy of the kidney:

Correct : B. the kidney contains 1.3 million nephrons

6. Regarding the glomerulus filtration fx:

Correct : A. it allows passage of molecules up to 4nm diameter freely, and up to 8nm with some difficulty depending on charge

7. The renal tubule:

Correct : B. the thick loop of Henle rises to lie adjacent to its glomerulus

8. Regarding glomerular blood supply:

Correct : C. the efferent arterioles empties into the peritubular network

9. If [urine]PAH = 14mg/ml, urine flow = 0.9ml/min and [plasma]PAH = 0.02mg/ml i) What is the clearance of PAH? ii) If the extraction ratio of PAH is 0.9, what is the renal blood flow (Hct=45%)?

Correct : A. ClPAH = 630, renal blood flow = 1273ml/min

10. Renal blood pressure:

Correct : D. the greatest drop in pressure (percentage wise) is from the efferent arteriole to the peritubular capillary

11. Regarding renal innervation:

Correct : D. autoregulation of renal blood flow can be disrupted by angiotensin-II inhibitors when renal perfusion is low

12. The glomerular filtration rate:

Correct : A. is usually in the order of 125mL/min for an average healthy male

13. Which of the following will cause an increase in GFR?

Correct : D. hypoproteinaemia

14. Na+ resorption does not occur in which part of the nephron?

Correct : B. thin descending loop of Henle

15. Which is NOT resorbed via cotransport with Na+ in the PCT?

Correct : C. hydrogen

16. Fanconi’s syndrome of decreased levels of ATP in the tubular epithelium of the PCT:

Correct : A. decreases Na+ extrusion from the cell into the interstitium

17. Anti-diuretic hormone controls the concentration of urine,

Correct : C. causing the ultimate resorption of up to 99.7% of the filtrate

18. Regarding H+ renal excretion:

Correct : D. CO2 is recycled / resorbed in the PCT to allow enhanced acid secretion

19. In the nervous control of the bladder which nerves do NOT play a role in micturition?

Correct : A. sympathetic nerves from L2 in hypogastric nerve

20. Which is the least significant buffering system in the blood?

Correct : B. H+ +HPO4 2- H2PO4-

21. In which body compartment is the bicarb buffering system least important?

Correct : A. intracellular

22. In which state is extracellular buffering more important than intracellular?

Correct : D. metabolic alkalosis

23. Renal acid secretion is enhanced by:

Correct : A. respiratory acidosis

24. Carbonic anhydrase is not inhibited by:

Correct : B. zinc

25. What increases GFR:

Correct : A. moderate constriction of efferent arterioles

26. What increases the anion gap:

Correct : D. increased concentration of ketoacids

27. Which is CORRECT?

Correct : D. nephrons length is 45-65mm

28. Which of the following is TRUE?

Correct : A. U/P ratio for creatinine is 150mg/dl

29. Which of the following is FALSE?

Correct : B. the cells in the descending loop of Henle have large numbers of mitochondria

30. Regarding tubular function:

Correct : D. the main mechanism of Na absorption in the ascending loop of Henle is via cotransport of Na/K/2Cl:

31. The maximum effect of vasopressin occurs at:

Correct : C. cortical part of the collecting duct

32. Regarding the buffer system in the tubular fluid, which one is TRUE?

Correct : D. the H+ secretion at proximal tubule is mediated Na/K/ATPase

33. Regarding the renin-angiotensin system, which is CORRECT?

Correct : C. renin is formed in the juxtaglomerular cells of the kidney

34. All of the following increase renin secretion EXCEPT:

Correct : C. hypertension

35. All of the following factors inhibit renin secretion EXCEPT:

Correct : A. prostaglandins

36. Which of the following blood gas results is consistent with a three-week residence at 4000m altitude, after previously living at sea-level? pH HCO3 - (meq/L) pCO2

Correct : E. 7.48 18.7 26

37. In a resting adult, the kidneys receive how much of the cardiac output?

Correct : C. 25%

38. Which of the following is INCORRECT regarding regulation of renal blood flow?

Correct : E. acetylcholine produces renal vasoconstriction

39. Erythropoietin:

Correct : D. has a half-life in the circulation of about 5 hours

40. Mesengial cell contraction is stimulated by:

Correct : E. angiotensin II

41. Ethanol’s action as a diuretic occurs by:

Correct : B. inhibition of the action of vasopressin on the collecting duct

42. With regard to diuretics:

Correct : A. frusemide acts on the thick ascending limb of the loop of Henle

43. In the presence of vasopressin, most filtered water is absorbed in the?

Correct : A. proximal tubule

44. Which pattern of laboratory findings in the tale below is most consistent with a diagnosis of diabetes insipidis? 24 Hr Urine Vol Ketones Glucose Protein

Correct : D. 6.4 0 0 0

45. On which of the following does aldosterone exert its greatest effect?

Correct : E. cortical collecting system

46. What is the clearance of a substance when its concentration in plasma is 1mg/ml, its concentration in urine is 10mg/ml and the urine flow is 2ml/min?

Correct : C. 20ml/min

47. Glucose reabsorption occurs in the:

Correct : A. proximal tubule

48. As urine flow increases during osmotic diuresis:

Correct : C. the osmolality of urine approaches that of plasma

49. Which of the following is NOT true regarding the voiding reflex?

Correct : B. it remains intact in the period of spinal shock following transaction of the spinalcord

50. Which of the following substances is NOT actively secreted in to the tubular lumen by the proximal renal tubule?

Correct : D. sodium

51. Angiotensin II causes:

Correct : A. greater constriction of efferent than afferent arterioles

52. With regard to the effect of hormones on renal tubules, which is CORRECT?

Correct : B. angiotensin II increases hydrogen ion secretion from the proximal tubules

53. With regard to tuboglomerular feedback:

Correct : C. the afferent arteriole is constricted by thromboxane A2

54. The primary reason for the decreased medullary hypertonicity associated with osmotic diuresis is:

Correct : B. the limiting concentration gradient for sodium reabsorption is reached

55. With respect to renal handling of glucose:

Correct : E. none of the above

56. Creatinine:

Correct : D. creatinuria occurs normally in the elderly and in pregnant women

57. The thin ascending loop of Henle is:

Correct : D. relatively impermeable to water

58. The primary effect of angiotensin II on renal vasculature is:

Correct : A. constriction of efferent arterioles

59. What percentage of filtered sodium is reabsorbed by the kidney?

Correct : C. 99%

60. Tuboglomerular feedback refers to:

Correct : C. decreased glomerular filtration associated with increased flow through the loop of Henle

61. Frusemide acts mainly at:

Correct : C. thick limb of loop of Henle

62. At which site does tubular fluid osmolality exceed that of plasma by the greatest amount?

Correct : B. thin limb of loop of Henle

63. At which site is sodium ion NOT actively reabsorbed?

Correct : B. thin limb of loop of Henle

64. At which site(s) is potassium ion secreted?

Correct : A. distal tubule and collecting duct

65. At which site does chlorthiazide act?

Correct : D. distal tubule

66. The cortical portion of the collecting duct has the capacity to reabsorb approximately 10% of the filtered water. Which substance is most important in regulating this effect?

Correct : C. vasopressin

67. With respect to GFR:

Correct : C. GFR is usually reduced in ureteric obstruction

68. With respect to the loop of Henle:

Correct : C. the thick ascending limb co-transports sodium, potassium and chloride out of the lumen

69. Mesangial cells:

Correct : C. are made to contract by angiotensin II

70. Regarding the proximal tubule, the following statements are true EXCEPT:

Correct : D. vasopressin increases the permeability to water by causing the rapid insertion of water channels into the luminal membrane

71. Renal autoregulation of GFR helps prevent large fluctuations in GFR despite wide variations in arterial blood pressure. With regard to autoregulation, which is TRUE?

Correct : D. decreased macula densa concentration of NaCl results in dilatation of afferent arterioles

72. Aldosterone has its principle effect in the:

Correct : E. collecting ducts

73. 85% of NaHCO3 in the filtrate is reabsorbed in the:

Correct : A. proximal convoluted tubule

74. Thiazide diuretics exert their main effect in the:

Correct : D. distal convoluted tubule

75. Ethacrynic acid exerts its principle effect in the:

Correct : C. thick ascending loop of Henle

76. When considering fluid balance, which of the following is INCORRECT?

Correct : B. urine output is always the single largest contributor to fluid output

77. Which of the following does NOT stimulate erythropoietin secretion?

Correct : B. thromboxanes

78. Glomerular filtration rate is best measured using:

Correct : A. inulin

79. “Renal dose” dopamine increases glomerular filtration rate by:

Correct : D. relaxing glomerular perivascular mesangial cells

80. Regarding the kidney:

Correct : C. glucose transport is an example of secondary active transport

81. Which of the following substances is not excreted by the kidney in a normal adult on an average diet?

Correct : D. glucose

82. Which of the following statements regarding erythropoietin is INCORRECT in an adult?

Correct : D. is secreted in adequate amounts by liver in absence of kidneys

83. “Renal dose” dopamine is:

Correct : D. 1-20 mcg/kg/min

84. Frusemide acts as a diuretic primarily by:

Correct : A. inhibiting Na+ /K+ /Cl- co-transport in loop of Henle

85. Regarding the osmolality of renal tubular fluid, is it?

Correct : B. isotonic in proximal tubule

86. Which of the following statements regarding renal tubular glucose absorption is INCORRECT?

Correct : A. binds to SGLT-2 in luminal membrane

87. Which of the following does NOT increase renal tubular sodium reabsorption?

Correct : E. glucagon

88. Regarding renal handling of glucose, which is INCORRECT?

Correct : D. phlorhizin inhibits distal tubular reabsorption

89. Regarding renal handling of sodium, which is INCORRECT?

Correct : C. aldosterone increases reabsorption despite increasing GFR

90. Which of the following agents cause relaxation of mesangial cells of the glomerulus?

Correct : B. dopamine

91. Regarding renal handling of bicarbonate ion, which is INCORRECT?

Correct : A. small size of bicarbonate ion affects reabsorption

92. Regarding renal handling of ammonia, which is INCORRECT?

Correct : E. ammonia diffusion can increase up to 30 fold

93. Regarding renal handling of calcium, which is INCORRECT?

Correct : B. growth hormone increases reabsorption

94. Regarding renal handling of chloride, which is INCORRECT?

Correct : C. it is actively secreted in distal tubule

95. Regarding glomerular filtration:

Correct : A. the glomerular filtration rate varies les than the renal plasma flow

96. Regarding renal handling of phosphate, which is INCORRECT?

Correct : D. less than 5% of filtered load is excreted

97. Regarding renal handling of hydrogen ion, which is INCORRECT?

Correct : E. secondary active transport mechanism operates in distal tubule

98. In diabetes insipidis:

Correct : D. urine concentration (msom/L) is markedly reduced

99. Which site of diuretic action is INCORRECT?

Correct : B. loop agents act in thin ascending limb

100. Which of the following statements regarding angiotensin is INCORRECT?

Correct : C. angiotensin III has equivalent pressor activity to angiotensin II