Quiznetik

Physiology | Set 6

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

A. the medullary chemoreceptors respond to a change in blood pCO2

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

C. the predominant peripheral chemoreceptors are located in the carotid and aortic bodies

D. the peripheral chemoreceptors respond to pO2

E. the peripheral chemoreceptors respond to blood (H+)

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

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

A. constriction of the renal vasculature

B. decreased velocity of conduction in the atrioventricular node

C. decreased velocity of conduction in the HIS/Purkinje system

D. decreased ventricular contractility

E. increased insulin and glucagon secretion

Correct : E. increased insulin and glucagon secretion

3. The reticular activating system:

A. has depressed conduction during anaesthesia

B. is located in the pons

C. is a simple collection of parallel nerve fibres

D. has no input from the cranial nerves

E. is electrically isolated from the cerebral cortex

Correct : A. has depressed conduction during anaesthesia

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

A. glucose

B. creatinine

C. sodium

D. urea

Correct : D. urea

5. Regarding the anatomy of the kidney:

A. the afferent arteriole is smaller than the efferent

B. the kidney contains 1.3 million nephrons

C. there are three layers separating the blood in the arteriole from the glomerular filtrate

D. podocytes are contractile and regulate GFR

Correct : B. the kidney contains 1.3 million nephrons

6. Regarding the glomerulus filtration fx:

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

B. positively charged molecules pass more easily than neutral

C. endothelial pores have a greater diameter than podocyte filtration slits

D. the basal lamina contains interruptions

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:

A. all sections are lined with cuboidal epithelial cells with luminal microvilli

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

C. there are a greater number of juxtamedullary nephrons than cortical

D. the lacis cells of the juxtaglomerular apparatus secrete renin

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

8. Regarding glomerular blood supply:

A. the efferent arterioles are branches of the interlobular arterioles

B. the descending vasa recta vessels contain fenestrated endothelium to assist urea transport

C. the efferent arterioles empties into the peritubular network

D. the glomerular capillaries drain into the efferent vein

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%)?

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

B. ClPAH = 630, renal blood flow = 700mb/min

C. ClPAH = 77, renal blood flow = 155mb/min

D. ClPAH = 777mb/min, renal blood flow = 1569mb/min

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

10. Renal blood pressure:

A. the pressure drop across the glomerulus is about 20mmHg

B. pressure in the renal vein is about 15mmHg

C. the glomerular capillary pressure is about 80% that of arterial

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

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

11. Regarding renal innervation:

A. transplanted kidneys initially have reduced concentrating ability because of lack of innervation of the juxtaglomerular cells and therefore decreased renin secretion

B. norepinephrine acts directly on α receptors on the juxtaglomerular cells

C. renal blood flow increases during exercise

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

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

12. The glomerular filtration rate:

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

B. is equal to the clearance of creatinine

C. is indirectly related to filtration coefficient

D. is determined by [urine]inulin

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?

A. dehydration

B. ureteral obstruction

C. afferent arteriole constriction

D. hypoproteinaemia

Correct : D. hypoproteinaemia

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

A. proximal convoluted tubule

B. thin descending loop of Henle

C. thick ascending loop of Henle

D. distal convoluted tubule

E. collecting duct

Correct : B. thin descending loop of Henle

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

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

B. causes increased phosphate absorption

C. causes metabolic alkalosis

D. results in decreased amino acid excretion

E. collecting duct

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

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

A. and can concentrate urine to up to 2500mosm/kg H??? H2O

B. in its absence, the collecting duct is impermeable to water

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

D. by causing upregulation of aquaporin-1 channels

E. collecting duct

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

18. Regarding H+ renal excretion:

A. the distal convoluted tubule brush border contains carbonic anhydrase

B. H+ secretion occurs in all segments of the nephrons

C. H+ + NH3 →NH4+ is the most significant tubular buffering reaction

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

E. collecting duct

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?

A. sympathetic nerves from L2 in hypogastric nerve

B. somatic motor neurons in pudendal nerve

C. sensory neurons to S2/3 in pelvic nerves

D. parasympathetic supply in pelvic nerves

E. collecting duct

Correct : A. sympathetic nerves from L2 in hypogastric nerve

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

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

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

23. Renal acid secretion is enhanced by:

25. What increases GFR:

A. moderate constriction of efferent arterioles

B. moderate constriction of afferent arterioles

C. increased Bowman’s capsule pressure

D. increased glomerular capillary osmotic pressure

E. collecting duct

Correct : A. moderate constriction of efferent arterioles

26. What increases the anion gap:

A. increased concentration of Mg2+

B. decreased concentration of plasma proteins

C. decreased concentration of lactate

D. increased concentration of ketoacids

E. collecting duct

Correct : D. increased concentration of ketoacids

27. Which is CORRECT?

A. humans have approximately 1.3 million nephrons

B. glomerular membrane excludes substances greater than 4nm in diameter

C. total area of glomerular capillary endothelium is 8m2

D. nephrons length is 45-65mm

E. collecting duct

Correct : D. nephrons length is 45-65mm

28. Which of the following is TRUE?

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

B. U/P ratio for glucose is 10

C. Na concentration in the urine usually exceeds over 150mg/dl

D. the usual glucose excretion in the urine is 100mg/dl

E. collecting duct

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

29. Which of the following is FALSE?

A. proximal convoluted tubular cells have lateral intercellular spaces

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

C. the ascending loop of Henle contributes to the formation of juxtaglomerular apparatus

D. in humans only 15% of the nephrons have long loops

E. collecting duct

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

30. Regarding tubular function:

A. 90% of the water is absorbed by the proximal convoluted tubule

B. renal threshold for glucose is 300mg/dl

C. the main mechanism of the Na reabsorption from the tubular fluid to proximal convoluted tubule is via Na/K/ATP a pump

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

E. collecting duct

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:

A. distal convoluted tubule

B. proximal convoluted tubule

C. cortical part of the collecting duct

D. medullary part of collecting duct

E. thick ascending limb of loop of Henle

Correct : C. cortical part of the collecting duct

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

A. the main buffer system is H2PO4

B. the main mechanism of H+ secretion in the proximal tubule is via proton pump

C. dibasic phosphate buffer is most effective at proximal convoluted tubule

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

E. thick ascending limb of loop of Henle

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

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

A. renin has many functions including the formation of angiotensin I from angiotensinogen

B. after nephrectomy, circulating levels of prorenin fall

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

D. active renin has a half-life in the circulation of 40 minutes or less

E. prorenin is biologically active

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

34. All of the following increase renin secretion EXCEPT:

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

A. prostaglandins

B. angiotensin II

C. vasopressin

D. increased afferent arteriolar pressure

E. increased Na+ and Cl- reabsorption across the macular densa

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

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

A. noradrenaline constricts the renal vessels

B. dopamine causes renal vasodilation and natriuresis

C. angiotensin II exerts a constrictor effect on the efferent arterioles

D. prostaglandins increase blood flow in the renal cortex and decrease blood flow in the renal medulla

E. acetylcholine produces renal vasoconstriction

Correct : E. acetylcholine produces renal vasoconstriction

39. Erythropoietin:

A. is produced in the juxtaglomerular cells of the kidney

B. production is stimulated by theophylline

C. secretion is facilitated by the acidosis that develops at high altitude

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

E. is produced predominantly in the spleen in neonates

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

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

A. inhibition of vasopressin secretion

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

C. production of an osmotic diuresis

D. decreasing tubular reabsorption of Na and increasing GFR

E. inhibition of the Na+ -K+ -Cl- cotransporter in the medullary thick ascending limb of the loop of Henle

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

42. With regard to diuretics:

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

B. antagonists to V2 vasopressin receptors act on the early portion of the distal convoluted tubule

C. thiazides act primarily on the thick ascending limb of the loop of Henle

D. loop diuretics act on the collecting ducts

E. aldosterone antagonists act on the early portion of the distal convoluted tubule

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?

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

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

A. glomerulus

B. proximal tubule

C. thin portion of loop of Henle

D. thick portion of look of Henle

E. cortical collecting system

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?

47. Glucose reabsorption occurs in the:

48. As urine flow increases during osmotic diuresis:

A. the osmolality of urine falls

B. the osmolality of urine increases

C. the osmolality of urine approaches that of plasma

D. the osmolality of urine is unchanged

E. the osmolality of urine depends primarily on other factors

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

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

A. it involves parasympathetic fibres

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

C. it occurs when the bladder volume reaches 300-400mls

D. it is integrated in the sacral segments of the spinal cord

E. its threshold is altered by inhibitory fibres from the brainstem

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?

51. Angiotensin II causes:

A. greater constriction of efferent than afferent arterioles

B. greater construction of afferent than efferent arterioles

C. constriction of afferent arterioles only

D. constriction of efferent arterioles only

E. has no effect on arteriolar constriction

Correct : A. greater constriction of efferent than afferent arterioles

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

A. aldosterone increases potassium reabsorption from the distal tubule

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

C. ADH increases water reabsorption in the proximal tubule

D. atrial naturetic peptide decreases sodium reabsorption from the proximal tubules

E. parathyroid hormone increases phosphate reabsorption

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

53. With regard to tuboglomerular feedback:

A. the GFR increases when flow through the distal tubule increases

B. the macula densa on the afferent arteriole is the sensor

C. the afferent arteriole is constricted by thromboxane A2

D. it is designed to maintain sodium reabsorption

E. it does not operate in individual nephrons

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

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

A. an associated increased urine volume

B. the limiting concentration gradient for sodium reabsorption is reached

C. tubular fluid has an increased sodium concentration

D. the total amount of sodium reaching the loop of Henle is increased

E. the associated maximal vasopressin secretion

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

55. With respect to renal handling of glucose:

A. glucose is reabsorbed from within the distal tubule by co-transport

B. glucose is reabsorbed from within the proximal tubule by facilitated diffusion

C. glucose is always completely reabsorbed

D. movement of glucose from tubular epithelial cells is by passive diffusion

E. none of the above

Correct : E. none of the above

56. Creatinine:

A. is synthesised in the liver from methionine, glycine and anganine

B. is converted directly to creatine

C. has variable excretion from day to day

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

E. all of the above

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

57. The thin ascending loop of Henle is:

A. relatively permeable to water

B. relatively impermeable to sodium ion

C. permeable to both water and sodium ion

D. relatively impermeable to water

E. relatively impermeable to both water and sodium ion

Correct : D. relatively impermeable to water

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

A. constriction of efferent arterioles

B. enhanced prostaglandin mediated increased blood flow to the renal cortex

C. enhanced catecholamine mediated afferent arteriolar vasoconstriction

D. enhanced catecholamine mediated afferent vasodilatation

E. constriction of interlobular arteries

Correct : A. constriction of efferent arterioles

60. Tuboglomerular feedback refers to:

A. the process of increased sodium reabsorption associated with an increased glomerular filtration

B. changes in peri-tubular oncotic pressure associated with changes in glomerular filtration

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

D. increased glomerular filtration associated with decreased peri-tubular oncotic pressure

E. thromboxane A2 mediated increased sodium reabsorption associated with increased renal blood flow

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

61. Frusemide acts mainly at:

A. proximal tubule

B. thin limb of loop of Henle

C. thick limb of loop of Henle

D. distal tubule

E. collecting duct

Correct : C. thick limb of loop of Henle

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

A. proximal tubule

B. thin limb of loop of Henle

C. thick limb of loop of Henle

D. distal tubule

E. collecting duct

Correct : B. thin limb of loop of Henle

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

A. proximal tubule

B. thin limb of loop of Henle

C. thick limb of loop of Henle

D. distal tubule

E. collecting duct

Correct : B. thin limb of loop of Henle

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

A. distal tubule and collecting duct

B. proximal tubule and distal tubule

C. think limb of loop of Henle only

D. thin limb and thick limb of loop of Henle

E. none of the above

Correct : A. distal tubule and collecting duct

65. At which site does chlorthiazide act?

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?

67. With respect to GFR:

A. clearance of p-amino hippuric acid is used to determine GFR

B. inulin cannot be used to measure GFR

C. GFR is usually reduced in ureteric obstruction

D. filtration pressure changes with change in blood pressure

E. contraction of mesangial cells increases GFR

Correct : C. GFR is usually reduced in ureteric obstruction

68. With respect to the loop of Henle:

A. the ascending limb is highly permeable to water

B. the descending limb is impermeable to water

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

D. tubular fluid becomes concentrated as it passes through the ascending limb

E. the ascending limb removes approximately 15% of filtered water

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

69. Mesangial cells:

A. are specialised cells that are characterised by numerous pseudopodia

B. are made to contract by dopamine

C. are made to contract by angiotensin II

D. lie within the renal medulla

E. decrease the area for filtration when they relax

Correct : C. are made to contract by angiotensin II

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

A. sodium is co-transported out of the tubule with glucose

B. sodium is actively transported into the intercellular spaces by Na-K-ATPase

C. the cells are characterised by a brush border and tight junctions

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

E. water moves passively out of the tubule along osmotic gradients

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?

A. the macula densa cells sense change in afferent arteriolar pressure

B. falling GFR results in a feedback to decrease efferent arteriolar pressure

C. falling GFR results in an increase in renin secretion from macula densa cells

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

E. decreased GFR decreases NaCl reabsorption in the ascending loop of Henle

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

72. Aldosterone has its principle effect in the:

A. proximal convoluted tubule

B. descending loop of Henle

C. thick ascending loop of Henle

D. distal convoluted tubule

E. collecting ducts

Correct : E. collecting ducts

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

A. proximal convoluted tubule

B. descending loop of Henle

C. thick ascending loop of Henle

D. distal convoluted tubule

E. collecting ducts

Correct : A. proximal convoluted tubule

74. Thiazide diuretics exert their main effect in the:

A. proximal convoluted tubule

B. descending loop of Henle

C. thick ascending loop of Henle

D. distal convoluted tubule

E. collecting ducts

Correct : D. distal convoluted tubule

75. Ethacrynic acid exerts its principle effect in the:

A. proximal convoluted tubule

B. descending loop of Henle

C. thick ascending loop of Henle

D. distal convoluted tubule

E. collecting ducts

Correct : C. thick ascending loop of Henle

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

A. the minimum daily fluid output may normally be estimated by measuring the urine output and adding 500ml

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

C. fluid intake and output may be altered in response to a change in extracellular osmolarity

D. fluid intake and output may be altered in response to a change in extracellular volume

E. the hypothalamus is an important regulator of fluid intake

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

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

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

A. dilating the renal arteries

B. dilating the vasa recta

C. constricting the efferent arteriole

D. relaxing glomerular perivascular mesangial cells

E. all of the above

Correct : D. relaxing glomerular perivascular mesangial cells

80. Regarding the kidney:

A. the glomerular filtration rate is 125mls/hr

B. the renal threshold for glucose 300mg/dL

C. glucose transport is an example of secondary active transport

D. the blood flow in the renal medulla is greater than in renal cortex

E. a high protein diet decreases renal blood flow

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?

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

A. half-life of about 5 hours

B. hypoxia can increase secretion within minutes

C. is secreted by spleen and salivary glands

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

E. is a glycoprotein

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

83. “Renal dose” dopamine is:

84. Frusemide acts as a diuretic primarily by:

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

B. inhibiting action of vasopressin on collecting duct

C. decreasing H+ secretion with resultant increase in Na+/K+ excretion

D. inhibiting vasopressin secretion

E. inhibiting Na+/K+ exchange in collecting ducts by inhibiting the action of aldosterone

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

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

A. hypotonic in loop of Henle

B. isotonic in proximal tubule

C. hypertonic in distal tubule

D. hypotonic in collecting duct

E. hypotonic in proximal tubule

Correct : B. isotonic in proximal tubule

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

A. binds to SGLT-2 in luminal membrane

B. example of secondary active transport

C. transported out of luminal cell by GLUT-2

D. about 100% reabsorption in proximal tubule if less than transport maximum

E. linked to sodium reabsorption

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

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

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

A. transport maximum varies depending on sex

B. proximal tubular absorption is an example of a symport mechanism

C. not all nephrons handle glucose filtration and reabsorption equally

D. phlorhizin inhibits distal tubular reabsorption

E. GLUT-2 transports glucose into interstitial fluid

Correct : D. phlorhizin inhibits distal tubular reabsorption

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

A. more than 95% of filtered sodium is reabsorbed

B. proximal tubular reabsorption is an example of secondary active transport

C. aldosterone increases reabsorption despite increasing GFR

D. glucocorticoids may increase or decrease urinary excretion

E. renal oxygen consumption is directly proportional to sodium reabsorption

Correct : C. aldosterone increases reabsorption despite increasing GFR

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

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

A. small size of bicarbonate ion affects reabsorption

B. reabsorption is reciprocally related to chloride ion reabsorption in proximal tubule

C. most reabsorption occurs in proximal tubule

D. reabsorption requires carbonic anhydrase

E. reabsorption is decreased by ECF expansion

Correct : A. small size of bicarbonate ion affects reabsorption

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

A. ammonia is not filtered at the glomerulus

B. ammonia is synthesised in proximal and distal tubules

C. glutaminase plays a role in ammonia excretion

D. non-ionic diffusion of ammonia maintains a concentration gradient for further diffusion

E. ammonia diffusion can increase up to 30 fold

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

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

A. metabolic acidosis decreases reabsorption

B. growth hormone increases reabsorption

C. calcium is actively reabsorbed

D. about 60% of filtered calcium load is reabsorbed in proximal tubules

E. glucocorticoids increase calcium reabsorption

Correct : B. growth hormone increases reabsorption

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

A. about 25% of filtered load is actively reabsorbed in thick ascending limb

B. proximal tubular reabsorption is reciprocally related to bicarbonate reabsorption

C. it is actively secreted in distal tubule

D. two chloride per sodium are reabsorbed in thick ascending limb

E. chloride-hydroxide antiport are present in the kidney

Correct : C. it is actively secreted in distal tubule

95. Regarding glomerular filtration:

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

B. inulin is stored in the kidney

C. sialoproteins in the glomerular capillary wall are positively charged

D. dopamine causes contraction of mesangial cells

E. changes in renal blood flow do not affect glomerular filtration rate

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

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

A. no tubular secretion occurs

B. most reabsorption occurs actively in proximal tubule

C. parathyroid hormone inhibits tubular reabsorption

D. less than 5% of filtered load is excreted

E. phosphate is a much more powerful buffer in tubular fluid than in blood

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

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

A. acetazolamide decreases tubular secretion

B. aldosterone increases distal tubular secretion

C. much more acid secretion occurs in proximal than distal tubule

D. lowest tubular fluid pH achievable is 4.5

E. secondary active transport mechanism operates in distal tubule

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

98. In diabetes insipidis:

A. percentage of filtered water reabsorbed is increased compared to normal

B. there is a net gain of water in excess of solute (L/day)

C. urine volume (L/day) is decreased

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

E. glomerular flow (ml/min) is increased

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

99. Which site of diuretic action is INCORRECT?

A. antidiuretic hormone antagonists act in collecting duct

B. loop agents act in thin ascending limb

C. carbonic anhydrase inhibitors act in proximal tubule

D. thiazides act in early distal tubule

E. aldosterone antagonists act in cortical collecting tubule

Correct : B. loop agents act in thin ascending limb

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

A. angiotensin II has a half-life of about 1-2 minutes

B. angiotensin I is physiologically inactive

C. angiotensin III has equivalent pressor activity to angiotensin II

D. angiotensinogen mainly comes from the liver

E. angiotensin converting enzyme is a dipeptidyl carboxypeptidase angiotensin converting enzyme

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

Quiznetik

Physiology | Set 6

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

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

3. The reticular activating system:

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

5. Regarding the anatomy of the kidney:

6. Regarding the glomerulus filtration fx:

7. The renal tubule:

8. Regarding glomerular blood supply:

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%)?

10. Renal blood pressure:

11. Regarding renal innervation:

12. The glomerular filtration rate:

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

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

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

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

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

18. Regarding H+ renal excretion:

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

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

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

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

23. Renal acid secretion is enhanced by:

24. Carbonic anhydrase is not inhibited by:

25. What increases GFR:

26. What increases the anion gap:

27. Which is CORRECT?

28. Which of the following is TRUE?

29. Which of the following is FALSE?

30. Regarding tubular function:

31. The maximum effect of vasopressin occurs at:

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

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

34. All of the following increase renin secretion EXCEPT:

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

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

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

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

39. Erythropoietin:

40. Mesengial cell contraction is stimulated by:

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

42. With regard to diuretics:

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

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

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

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?

47. Glucose reabsorption occurs in the:

48. As urine flow increases during osmotic diuresis:

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

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

51. Angiotensin II causes:

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

53. With regard to tuboglomerular feedback:

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

55. With respect to renal handling of glucose:

56. Creatinine:

57. The thin ascending loop of Henle is:

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

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

60. Tuboglomerular feedback refers to:

61. Frusemide acts mainly at:

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

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

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

65. At which site does chlorthiazide act?

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?

67. With respect to GFR:

68. With respect to the loop of Henle:

69. Mesangial cells:

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

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?

72. Aldosterone has its principle effect in the:

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

74. Thiazide diuretics exert their main effect in the:

75. Ethacrynic acid exerts its principle effect in the:

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

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

78. Glomerular filtration rate is best measured using: