Florida International University

BIO PCB 4023

Chapter 18

1)Which of the following is NOT a function of the kidneys?

1. 1. regulation of plasma ionic concentration
   2. regulation of plasma hydrogen concentration
   3. regulation of plasma osmolarity
   4. regulation of plasma temperature
   5. regulation of plasma volume Answer: D
2. The primary function of the kidneys involves regulating the                        and the       of plasma and interstitial fluid.
   1. volume : composition
   2. temperature : composition
   3. volume : temperature
   4. pressure : volume
   5. composition : osmolarity Answer: A
3. Once produced, urine travels through the            until it reaches the bladder, from which it is released into the external environment through the     .
   1. ureter : urethra
   2. urethra : ureter
   3. collecting duct : ureter
   4. renal hilus : ureter
   5. collecting duct : urethra Answer: A
4. What hormone is secreted by the kidneys to increase red blood cell synthesis?
   1. ANP
   2. vitamin D
   3. renin
   4. erythropoietin
   5. angiotensin Answer: D
5. Despite being less than 1% of body weight, the kidneys receive what percent of resting cardiac output? A) 35% B) 5% C) 20% D) 15% E) 1%

Answer: C

6. What are the conical sections of the renal medulla called?
   1. renal pelvis
   2. major calyces
   3. renal cortex
   4. minor calyces
   5. renal pyramids Answer: E

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7. Where do the collecting ducts of the renal tubules drain?
   1. major calyces
   2. minor calyces
   3. ureters
   4. glomerulus
   5. renal pelvis Answer: B
8. What is the functional unit of the kidney?
   1. glomerulus
   2. loop of Henle
   3. collecting ducts
   4. proximal tubule
   5. nephron

Answer: E

9. What two structures make up the renal corpuscle?
   1. Bowman's capsule and glomerulus
   2. afferent and efferent arterioles
   3. proximal straight and proximal convoluted tubules
   4. nephron and collecting duct
   5. major and minor calyces Answer: A
10. Blood leaves the          and enters the glomerulus.
    1. vasa recta
    2. efferent arteriole
    3. Bowman's capsule
    4. peritubular capillary
    5. afferent arteriole Answer: E
11. Where does blood leaving the glomerulus go next?
    1. Bowman's capsule
    2. vasa recta
    3. afferent arteriole
    4. efferent arteriole
    5. peritubular capillary Answer: D
12. After fluid passes through the entire proximal tubule, the fluid will enter the
    1. distal tubule.
    2. connecting tubule.
    3. loop of Henle.
    4. collecting duct.
    5. Bowman's capsule. Answer: C

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13. What type of nephron is located within the outer region of the kidney and comprises nearly 80% of the nephrons?
    1. cortical
    2. juxtaglomerular
    3. juxtamedullary
    4. medullary
    5. peritubular Answer: A
14. The juxtaglomerular apparatus describes the unique region of the nephron where the
    1. afferent and efferent arterioles are in contact with the distal tubule.
    2. afferent and efferent arterioles are in contact with the proximal tubule.
    3. afferent arteriole is in contact with the proximal tubule.
    4. afferent arteriole is in contact with the distal tubule.
    5. efferent arteriole is in contact with the distal tubule. Answer: A
15. What capillaries come off of the efferent arterioles associated with cortical nephrons?
    1. peritubular B) arcuate C) vasa recta D) lobular E) glomerulus Answer: A
16. What capillaries come off of the efferent arterioles associated with juxtamedullary nephrons?
    1. peritubular B) glomerulus C) arcuate D) lobular E) vasa recta Answer: E
17. Which of the following is the correct order of blood supply to the kidneys?
    1. renal artery, segmental arteries, interlobular arteries, arcuate arteries, interlobar arteries, efferent arteriole, glomerulus, afferent arteriole
    2. renal artery, arcuate arteries, interlobular arteries, segmental arteries, afferent arteriole, glomerulus, efferent arteriole, interlobar arteries

1. 3. renal artery, interlobar arteries, arcuate arteries, segmental arteries, interlobular arteries, efferent arteriole, glomerulus, afferent arteriole
   4. renal artery, segmental arteries, interlobar arteries, arcuate arteries, interlobular arteries, afferent arteriole, glomerulus, efferent arteriole
   5. renal artery, interlobar arteries, interlobular arteries, arcuate arteries, segmental arteries, afferent arteriole, glomerulus, efferent arteriole

Answer: D

18. During what renal process are molecules selectively removed from the tubule lumen, moved into the interstitial space, and removed from the kidneys by the peritubular capillaries and the vasa recta?
    1. filtration
    2. secretion
    3. excretion
    4. absorption
    5. reabsorption Answer: E

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19. The peritubular capillaries and vasa recta drain into what veins?
    1. interlobular
    2. interlobar
    3. arcuate
    4. segmental
    5. efferent Answer: A
20. As fluid moves out of the glomerular capillaries, it passes through gaps in the podocytes called slit pores, whose size is regulated by what?
    1. slit muscle
    2. corpuscle
    3. glomerular capillary
    4. slit diaphragm
    5. fenestrations Answer: D
21. What is the process whereby molecules are selectively transported from the peritubular fluid to the lumen of the renal tubules?
    1. glomerular filtration
    2. reabsorption
    3. secretion
    4. absorption
    5. excretion Answer: C
22. What is the process whereby protein-free plasma moves by bulk flow from the glomerulus into Bowman's capsules?
    1. reabsorption
    2. absorption
    3. excretion
    4. glomerular filtration
    5. secretion Answer: D
23. Which of the following forms the filtration barrier?
    1. capillary endothelial cells only
    2. podocytes only
    3. basement membrane only
    4. both capillary endothelial cells and basement membrane
    5. capillary endothelial cells, basement membrane, and podocytes Answer: E
24. What is the sum of Starling's forces within the renal corpuscle called?
    1. glomerular capillary hydrostatic pressure

1. 2. glomerular filtration rate
   3. glomerular filtration volume
   4. glomerular oncotic pressure
   5. glomerular filtration pressure Answer: E

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25. What Starling force, which drives fluid out of the glomerulus, is relatively high (~60 mm Hg) due to the resistance of the efferent arterioles?
    1. glomerular capillary hydrostatic
    2. glomerular oncotic
    3. glomerular filtration
    4. Bowman's capsule oncotic
    5. Bowman's capsule hydrostatic Answer: A
26. Which of the following pressures across the glomerular capillaries approaches zero?
    1. glomerular capillary hydrostatic pressure
    2. glomerular oncotic pressure
    3. Bowman's capsule oncotic pressure
    4. glomerular filtration pressure
    5. Bowman's capsule hydrostatic pressure Answer: C
27. Which of the forces across the glomerular capillaries tends to increase from the afferent to the efferent arteriole ends?
    1. Bowman's capsule hydrostatic pressure
    2. glomerular oncotic pressure
    3. glomerular capillary hydrostatic pressure
    4. glomerular filtration pressure
    5. Bowman's capsule oncotic pressure Answer: B
28. Which equation describes the calculation of glomerular filtration pressure (BC = Bowman's capsule and GC = glomerular capillary)?
    1. (PBC + !GC) - (PGC + !BC)
    2. (PGC + !BC) - (PBC + !GC)
    3. (PGC + !GC) - (PBC + !BC)
    4. (PBC + !BC) - (PGC + !GC)
    5. (PGC + PBC) - (!GC + !BC) Answer: B
29. Which of the following conditions would increase glomerular filtration pressure?
    1. increased resistance of the afferent arteriole
    2. increased Bowman's capsule pressure
    3. increased protein in Bowman's space
    4. increased protein content in the blood
    5. decreased resistance of the efferent arterioles Answer: C

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30. Which of the following equations is correct for calculating the filtered load?
    1. glomerular filtration pressure / renal plasma flow
    2. glomerular filtration pressure × plasma concentration of solvent
    3. glomerular filtration pressure × plasma concentration of solute
    4. glomerular filtration rate × plasma concentration of solute
    5. glomerular filtration rate / renal plasma flow Answer: D
31. Changes in mean arterial pressure have the potential to alter glomerular filtration rate by directly altering which of the following?
    1. glomerular oncotic pressure
    2. efferent arteriole resistance

31. 3. Bowman's capsule hydrostatic pressure
    4. glomerular capillary hydrostatic pressure
    5. Bowman's capsule oncotic pressure Answer: D
32. What is the normal glomerular filtration rate?
    1. 125 mL/min
    2. 1 gallon/day
    3. 30 L/day
    4. 3 L/day
    5. 625 mL/min Answer: A
33. If the glomerular filtration rate is 150 mL/min, renal blood flow is 750 mL/min, and the plasma concentration of solute X is 10 ng/mL, then what is the filtration fraction?
    1. 50 ng/min
    2. 75 ng/min

C) 20%

D) 1500 ng/min

E) 10%

Answer: C

34. If the glomerular filtration rate is 150 mL/min, renal blood flow is 750 mL/min, and the plasma concentration of solute X is 10 ng/mL, then what is the filtered load of X?
    1. 50 ng/min
    2. 7500 ng/min

C) 10%

D) 1500 ng/min

E) 20%

Answer: D

35. Which of the following can increase the filtered load of a particular solute?
    1. decreasing the rate of excretion
    2. decreasing the plasma concentration of the solute
    3. increasing the rate of reabsorption
    4. increasing the rate of secretion
    5. increasing the glomerular filtration rate Answer: D

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36. Over what range of mean arterial pressure does glomerular filtration rate remain stable due to intrinsic regulation?
    1. 70-110 mm Hg
    2. 80-120 mm Hg
    3. 50-150 mm Hg
    4. 80-100 mm Hg
    5. 80-180 mm Hg Answer: E
37. During myogenic regulation of glomerular filtration rate, an increase in mean arterial pressure will cause the
    1. afferent arterioles to dilate and thereby allow glomerular filtration pressure to increase.
    2. afferent arterioles to constrict and thereby maintain a relatively constant glomerular filtration pressure.
    3. efferent arterioles to dilate and thereby maintain a relatively constant glomerular filtration pressure.
    4. efferent arterioles to constrict and thereby maintain a relatively constant glomerular filtration pressure.
    5. afferent arterioles to dilate and thereby maintain a relatively constant glomerular filtration pressure. Answer: B
38. In tubuloglomerular feedback, an increase in glomerular filtration rate would increase the  , thereby stimulating the release of a paracrine factor from the macula densa that would         .
    1. afferent arteriolar pressure : increase filtrate flow
    2. flow of tubular fluid : constrict the efferent arteriole
    3. flow of tubular fluid : dilate the afferent arteriole
    4. flow of tubular fluid : constrict the afferent arteriole

38. 5. afferent arteriolar pressure : constrict the afferent arteriole Answer: D
39. Contraction of mesangial cells results in a(n) , which decreases glomerular filtration.
    1. dilation of the efferent arterioles
    2. dilation of the afferent arterioles
    3. constriction of the afferent arterioles
    4. increase in surface area of capillaries available for filtration
    5. decrease in surface area of capillaries available for filtration Answer: E
40. Which of the following is NOT a mechanism whereby glomerular filtration rate is regulated?
    1. mesangial cell contraction
    2. myogenic regulation
    3. granular cell contraction
    4. sympathetic nervous system
    5. tubuloglomerular feedback Answer: C
41. A hemorrhage-induced decrease in mean arterial pressure will decrease glomerular filtration rate by intrinsic and extrinsic mechanisms; the extrinsic mechanisms act through
    1. mesangial cells.
    2. the parasympathetic nervous system.
    3. myogenic responses.
    4. the sympathetic nervous system.
    5. tubuloglomerular feedback. Answer: D

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42. How does the sympathetic nervous system decrease glomerular filtration rate?
    1. stimulates constriction of the efferent arteriole only
    2. stimulates contraction of mesangial cells
    3. stimulates constriction of the afferent arteriole only
    4. stimulates constriction of both the afferent and efferent arterioles
    5. stimulates relaxation of the mesangial cells Answer: D
43. What is the primary barrier to reabsorption in the renal tubules?
    1. capillary basement membrane
    2. tubule basement membrane
    3. peritubular space
    4. capillary endothelial cell
    5. tubule epithelial cell Answer: E
44. What condition(s) must exist for a solute to be passively reabsorbed from the renal tubules?
    1. The solute must be able to permeate the membrane of the capillary endothelial cells, and the solute must be in greater concentration in the tubule fluid than plasma.
    2. The solute must be able to permeate the membrane of the capillary endothelial cells, and the solute must be in greater concentration in the plasma than tubule fluid.
    3. The solute must be able to permeate the membrane of the tubule epithelial cells, and the solute must be in greater concentration in the tubule fluid than plasma.
    4. The solute must be able to permeate the membrane of the tubule epithelial cells and capillary endothelial cells. Its concentration is irrelevant.
    5. The solute must be able to permeate the membrane of the tubule epithelial cells, and the solute must be in greater concentration in the plasma than tubule fluid.

Answer: C

45. Within the kidneys, what membrane has microvilli?
    1. basolateral membrane of renal tubule epithelial cells
    2. apical membrane of renal tubule epithelial cells
    3. glomerulus
    4. basolateral membrane of peritubular capillary endothelial cells

45. 5. apical membrane of vasa recta endothelial cells Answer: B
46. The apical membranes of the tubular epithelial cells contain   that increase the surface area for reabsorption.
    1. microvilli
    2. loose junctions
    3. tight junctions
    4. a basement membrane
    5. mitochondria Answer: A

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47. The diffusion of water across a tubule is driven by differences in         across the membrane.
    1. active transport
    2. osmolarity
    3. potassium concentration
    4. partial pressure
    5. volume Answer: B
48. When the solute concentration is high enough in the lumen of the renal tubules such that all of the carrier proteins or pumps for that solute are occupied, the system is operating at
    1. renal threshold.
    2. transport maximum.
    3. tubular threshold.
    4. tubular maximum.
    5. diffusional saturation.

Answer: B

49. The concentration of glucose in tubular epithelial cells is maintained in an elevated state by what type of transporter on the apical membrane?
    1. ion channel
    2. glucose-linked secondary active transporter
    3. potassium-linked secondary active transporter
    4. carrier protein
    5. sodium-linked secondary active transporter Answer: E
50. Which of the following is FALSE concerning glucose transport across the proximal tubule?
    1. Glucose transport requires energy.
    2. Glucose is normally 100% reabsorbed.
    3. Glucose is passively transported across the basolateral membrane by facilitated diffusion.
    4. Glucose moves by paracellular transport.
    5. Glucose is actively transported across the apical membrane by cotransport with sodium. Answer: D
51. Which of the following is FALSE concerning renal handling of glucose?
    1. The maximum rate of glucose reabsorption is 375 mg/min.
    2. Glucose is actively reabsorbed in the proximal tubule.
    3. The maximum rate of glucose filtration is 375 mg/min.
    4. Once glucose concentration in the plasma exceeds the renal threshold, glucose will be excreted in the urine.
    5. Glucose is completely reabsorbed when its plasma concentration is 100 mg/dL. Answer: C
52. Which of the following substances is NOT secreted at any point into the renal tubules?
    1. hydrogen B) potassium C) choline D) sodium E) creatinine Answer: D

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53. By the time filtrate reaches the loop of Henle, what percentage of the sodium and water has been reabsorbed?

A) 100% B) 90% C) 1% D) 70% E) 50%

Answer: D

54. By the time the filtrate reaches the loop of Henle, the reabsorption of water and ions has
    1. removed all of the potassium from the filtrate.
    2. left the filtrate iso-osmotic.
    3. left the filtrate hypoosmotic.
    4. left the filtrate hyperosmotic.
    5. removed all of the sodium from the filtrate. Answer: B
55. Which of the following is NOT an accurate description of differences between epithelial cells of the proximal and distal tubules?
    1. fewer mitochondria in the epithelial cells of the distal tubule
    2. greater paracellular transport in the epithelial cells of the distal tubule
    3. less prominent microvilli in the epithelial cells of the distal tubule
    4. less permeable tight junctions between the epithelial cells of the distal tubule
    5. receptors for hormones on the epithelial cells of the distal tubule Answer: B
56. In diabetes mellitus, why does polyuria occur?
    1. Hyperglycemia causes some glucose to remain in the renal tubules which pulls water with it by osmosis.
    2. Hyperglycemia causes increased permeability of the renal tubules to water.
    3. A lack of ADH decreases water reabsorption.
    4. A lack of insulin decreases water reabsorption.
    5. Hypoglycemia causes the excretion of a dilute urine. Answer: A
57. What is the brush border?
    1. the epithelial cells of the renal corpuscle
    2. tight junctions between epithelial cells of the loops of Henle
    3. tight junctions between epithelial cells of the distal tubule
    4. microvilli on the apical membrane of the proximal tubule
    5. microvilli on the apical membrane of Bowman's capsule Answer: D
58. Most reabsorption occurs in the     and is             .
    1. proximal tubule : not regulated
    2. distal tubule and collecting duct : not regulated
    3. distal tubule and collecting duct : regulated
    4. loop of Henle : regulated
    5. proximal tubule : regulated Answer: A

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59. Tubular epithelial cells of the collecting duct and distal tubule contain receptors for what hormone that stimulates sodium reabsorption?
    1. antidiuretic hormone
    2. aldosterone
    3. erythropoietin
    4. renin
    5. atrial natriuretic peptide Answer: B
60. Tubular epithelial cells of the collecting duct and distal tubule contain receptors for what hormone that stimulates water reabsorption?
    1. atrial natriuretic peptide
    2. erythropoietin
    3. renin
    4. antidiuretic hormone
    5. aldosterone Answer: D
61. What creates the osmotic gradient in the renal medulla?

61. 1. passive transport of solute out of the distal tubules and collecting ducts
    2. active transport of solute out of the distal tubules and collecting ducts
    3. special transport systems of the loops of Henle of cortical nephrons
    4. active transport of solute out of the proximal tubule
    5. special transport systems of the loops of Henle of juxtamedullary nephrons Answer: E
62. Substances can enter the renal tubules by what renal processes?
    1. filtration only
    2. reabsorption only
    3. secretion only
    4. both filtration and secretion
    5. both reabsorption and secretion Answer: D
63. The amount of a substance excreted from the kidneys is calculated by which of the following equations?
    1. filtration - (secretion × reabsorption)
    2. filtration + (secretion × reabsorption)
    3. filtration - secretion - reabsorption
    4. filtration + secretion + reabsorption
    5. filtration + secretion - reabsorption Answer: E
64. Solutes that enter the lumen of the renal tubules are excreted unless they are
    1. filtered.
    2. bound to receptors.
    3. degraded.
    4. reabsorbed.
    5. secreted. Answer: D 11
65. If the amount of solute excreted per minute is greater than the filtered load, then the NET effect on the solute is
    1. an absence of reabsorption in the renal tubules.
    2. secretion into the renal tubules.
    3. an absence of secretion in the renal tubules.
    4. a combination of reabsorption and secretion in the renal tubules.
    5. reabsorption from the renal tubules. Answer: B
66. Which of the following equations for determining clearance is correct?
    1. clearance = excretion rate / glomerular filtration rate
    2. clearance = filtered load × glomerular filtration rate
    3. clearance = excretion rate / plasma concentration
    4. clearance = excretion rate × plasma concentration
    5. clearance = filtered load / glomerular filtration rate Answer: C
67. Which of the following equations for determining clearance is correct?
    1. clearance = (plasma concentration × urine flow rate) / urine concentration
    2. clearance = urine concentration (plasma concentration × urine flow rate)
    3. clearance = (urine concentration × urine flow rate) / plasma concentration
    4. clearance = plasma concentration / (urine concentration × urine flow rate)
    5. clearance = GRF × urine concentration Answer: C
68. Calculate renal clearance of X given the following information: GFR = 100 mL/min, urine flow rate = 5 mL/min, plasma concentration of X = 10 mg/mL, urine concentration of X = 50 mg/mL.
    1. Y is freely filterable.
    2. Y is reabsorbed.
    3. Y is secreted.
    4. Y is neither reabsorbed nor secreted.

1. 5. Y is not freely filtered.

Answer: B

69. Given that GFR is 125 mL/min and the clearance of substance Y is 200 mL/min, which of the following MUST be true of the renal handling of substance Y?
    1. Y is freely filterable.
    2. Y is reabsorbed.
    3. Y is secreted.
    4. Y is neither reabsorbed nor secreted.
    5. Y is not freely filtered.

Answer: A

70. The clearance of what substance provides the best estimate of glomerular filtration rate?
    1. inulin B) glucose C) creatine D) PAH E) sodium Answer: A
71. The clearance of what substance provides the best estimate of renal blood flow rate?
    1. inulin B) glucose C) PAH D) creatine E) sodium Answer: C

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72. The clearance of which of the following substances is normally zero?
    1. inulin B) creatine C) PAH D) glucose E) sodium Answer: D
73. If a substance is neither reabsorbed nor secreted, then its excretion rate is equal to the
    1. filtered load. B) glomerular filtration rate.

C) renal threshold. D) plasma concentration of the substance. Answer: A

74. What structure is formed by the thickening of the smooth muscle cell wall surrounding the bladder that regulates the flow of urine from the bladder?
    1. bladder sphincter
    2. detrusor muscle
    3. external urethral sphincter
    4. internal urethral sphincter
    5. urethral muscle Answer: D
75. How is urine moved through the ureter?
    1. wavelike contractions of the ureter
    2. pressure created within the renal pelvis
    3. contraction of the internal urethral sphincter
    4. contraction of the external urethral sphincter
    5. contraction of the detrusor muscle Answer: A
76. Which muscle(s) that regulate(s) micturition is/are under involuntary control?
    1. detrusor
    2. detrusor and the external urethral sphincter
    3. external urethral sphincter
    4. internal urethral sphincter
    5. detrusor and the internal urethral sphincter Answer: E
77. Which of the following occurs during micturition?
    1. The detrusor muscles relax, muscles of the internal urethral sphincter relax, and muscles of the external urethral sphincter relax.
    2. The detrusor muscles contract, muscles of the internal urethral sphincter relax, and muscles of the external urethral sphincter relax.
    3. The detrusor muscles contract, muscles of the internal urethral sphincter contract, and muscles of the external urethral sphincter contract.
    4. The detrusor muscles relax, muscles of the internal urethral sphincter contract, and muscles of the external urethral sphincter relax.
    5. The detrusor muscles relax, muscles of the internal urethral sphincter contract, and muscles of the

external urethral sphincter contract. Answer: B

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78. Stretching of the bladder reflexively causes all of the following EXCEPT
    1. micturition.
    2. inhibition of somatic neurons to the external urethral sphincter, causing the sphincter to open.
    3. excitation of sympathetic neurons, causing the internal urethral sphincter to relax.
    4. excitation of parasympathetic neurons, causing the detrusor muscles to contract.
    5. opening of the urethral sphincters. Answer: C
79. What effect does the sympathetic nervous system have on micturition?
    1. Sympathetic activity excites muscles of the external urethral sphincter allowing micturition.
    2. Sympathetic activity inhibits muscles of the external urethral sphincter inhibiting micturition.
    3. Sympathetic activity excites muscles of the internal urethral sphincter inhibiting micturition.
    4. Sympathetic activity inhibits muscles of the internal urethral sphincter inhibiting micturition.
    5. Sympathetic activity excites muscles of the internal urethral sphincter allowing micturition. Answer: C
80. Which of the following is smooth muscle?
    1. internal urethral sphincter only
    2. external urethral sphincter only
    3. detrusor muscle only
    4. both the internal urethral sphincter and detrusor muscle
    5. both internal and external urethral sphincters Answer: D
81. To voluntarily control urination, the     nervous system innervates the     .
    1. somatic : internal urethral sphincter
    2. somatic : external urethral sphincter
    3. autonomic : external urethral sphincter
    4. autonomic : internal urethral sphincter
    5. somatic : detrusor muscle Answer: B
82. During micturition, neural activity to sphincters or detrusor muscles from which of the following is increased?
    1. parasympathetic nervous system only
    2. sympathetic nervous system only
    3. somatic nervous system only
    4. both parasympathetic and somatic nervous systems
    5. both sympathetic and somatic nervous systems Answer: A
83. In older children and adults, the cerebral cortex is able to block micturition by inhibiting nerve activity to the
    1. detrusor muscle only.
    2. external urethral sphincter only.
    3. internal urethral sphincter only.
    4. detrusor muscle and external urethral sphincter.
    5. internal and external urethral sphincters. Answer: A

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84. Substance X is freely filtered at the glomerulus. 3 mmole X is filtered, 2 mmole X is reabsorbed, and 2 mmole X is secreted per minute. How much X is excreted per minute?
    1. 1 mmole B) 2 mmole C) 3 mmole D) 4 mmole E) 5 mmole Answer: C
85. During tubuloglomerular feedback of glomerular filtration rate, paracrines secreted from what structure(s) cause constriction of the afferent arteriole?
    1. glomerulus
    2. juxtaglomerular cells
    3. macula densa

85. 4. proximal tubule
    5. mesangial cells Answer: C
86. In comparison to the distal tubule, the proximal tubule has a
    1. small apical surface area and is more responsive to hormones.
    2. tighter epithelium and a larger apical surface area.
    3. tighter epithelium and is more responsive to hormones.
    4. leakier epithelium and a larger apical surface area.
    5. leakier epithelium and is more responsive to hormones. Answer: D
87. What is the site where filtrate enters renal tubules?
    1. proximal tubule
    2. collecting duct
    3. distal tubule
    4. loop of Henle
    5. Bowman's capsule Answer: E
88. Most filtered solutes and water are reabsorbed in what region?
    1. loop of Henle
    2. proximal tubule
    3. Bowman's capsule
    4. collecting duct
    5. distal tubule Answer: B
89. Filtrate moves from what structure to the loop of Henle?
    1. distal tubule
    2. proximal tubule
    3. Bowman's capsule
    4. collecting duct
    5. loop of Henle Answer: B

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90. Located entirely within the cortex, reabsorption of water and certain solutes from which region is under hormonal control?
    1. distal tubule
    2. loop of Henle
    3. Bowman's capsule
    4. proximal tubule
    5. collecting duct Answer: A
91. In juxtamedullary nephrons, which region sets up the medullary osmotic gradient?
    1. Bowman's capsule
    2. loop of Henle
    3. distal tubule
    4. proximal tubule
    5. collecting duct Answer: B
92. Which tubule drains into the minor calyces?
    1. distal tubule
    2. Bowman's capsule
    3. loop of Henle
    4. collecting duct
    5. proximal tubule Answer: D
93. What structure filters the blood to regulate its composition?
    1. kidneys B) bladder C) liver D) ureter E) urethra

Answer: A

94. What structure stores urine prior to micturition?
    1. kidneys B) bladder C) ureter D) urethra E) liver Answer: B
95. What structure transports urine from the kidneys to the bladder?
    1. ureter B) liver C) kidneys D) bladder E) urethra Answer: A
96. What structure transports urine from the bladder to outside of the body?
    1. ureter B) urethra C) liver D) bladder E) kidneys Answer: B
97. Which of the following describes movement from glomerular capillaries into Bowman's capsule?
    1. reabsorption
    2. filtration
    3. micturition
    4. secretion
    5. excretion Answer: B 16
98. Which of the following describes movement from renal tubules into the peritubular capillaries?
    1. secretion
    2. excretion
    3. reabsorption
    4. micturition
    5. filtration Answer: C
99. Which of the following describes movement from peritubular capillaries into the renal tubules?
    1. micturition
    2. secretion
    3. excretion
    4. filtration
    5. reabsorption Answer: B
100. Which of the following describes elimination of urine from the body?

1. filtration
2. secretion
3. excretion
4. micturition
5. reabsorption Answer: C

101. Constriction of which vessel, by intrinsic or extrinsic mechanisms, decreases glomerular filtration rate?

1. peritubular capillary
2. glomerulus
3. vasa recta
4. afferent arteriole
5. efferent arteriole Answer: D

102. Substances that are reabsorbed from the proximal tubule enter which blood vessel?

1. afferent arteriole
2. efferent arteriole
3. vasa recta
4. peritubular capillary
5. glomerulus Answer: D

103. Filtration occurs across which capillary bed?

1. glomerulus
2. peritubular capillary

3. vasa recta
4. afferent arteriole
5. efferent arteriole Answer: A

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104. After blood is filtered in the renal corpuscle, the blood continues moving through which blood vessel to another capillary bed?

1. efferent arteriole
2. glomerulus
3. vasa recta
4. afferent arteriole
5. peritubular capillary Answer: A

105. Which capillary bed dips down into the renal medulla with the loop of Henle?

1. vasa recta
2. afferent arteriole
3. glomerulus
4. peritubular capillary
5. efferent arteriole Answer: A

106. Which of the following are modified smooth muscle cells around the glomerulus that contract to decrease the surface area of the glomerulus available for filtration?

1. macula densa cells
2. granular cells
3. endothelial cells
4. mesangial cells
5. podocytes Answer: D

107. Which of the following are epithelial cells of Bowman's capsule that form part of the filtration barrier?

1. mesangial cells
2. macula densa cells
3. granular cells
4. podocytes
5. endothelial cells Answer: D

108. Which cells of the afferent arteriole secrete renin?

1. mesangial cells
2. granular cells
3. macula densa cells
4. endothelial cells
5. podocytes Answer: B

109. Which cells of the distal tubule secrete a paracrine in response to changes in the filtrate flow rate?

1. granular cells
2. podocytes
3. endothelial cells
4. mesangial cells
5. macula densa cells Answer: E

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110. What is the GFR/renal plasma flow equal to?

1. filtered load
2. excretion rate
3. renal blood flow
4. clearance
5. filtration fraction

Answer: E

111. What is the GFR × plasma concentration equal to?

1. clearance
2. filtered load
3. renal blood flow
4. excretion rate
5. filtration fraction Answer: B

112. What is the excretion rate/plasma concentration equal to?

1. clearance
2. filtered load
3. excretion rate
4. renal blood flow
5. filtration fraction Answer: A

113. What is the urine concentration × urine flow rate equal to?

1. filtered load
2. excretion rate
3. clearance
4. renal blood flow
5. filtration fraction Answer: B

114. What is the (urine concentration × urine flow rate)/plasma concentration equal to?

1. excretion rate
2. filtration fraction
3. filtered load
4. clearance
5. renal blood flow Answer: D

115. What is the (clearance of PAH)/(1 - hematocrit) equal to?

1. filtered load
2. excretion rate
3. filtration fraction
4. clearance
5. renal blood flow Answer: E

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116. What is the region of the kidney where the renal artery and vein enter?

A) calyx B) columns C) medulla D) hilus E) pyramids Answer: D

117. What two structures make up the renal corpuscle?

1. juxtaglomerular apparatus and macula densa
2. proximal and distal tubules
3. proximal tubule and loop of Henle
4. afferent arteriole and efferent arteriole
5. Bowman's capsule and the glomerulus Answer: E

118. What are the three components of the loop of Henle?

1. thick descending limb, thin descending limb, and thick ascending limb
2. proximal tubule, loop, and the distal tubule
3. descending limb, ascending limb, and the vasa recta
4. descending limb, thin ascending limb, and thick ascending limb
5. descending limb, ascending limb, and the bend Answer: D

119. What are a small percentage of the nephrons in the kidneys that function in the maintenance of the osmotic gradient in the medullary region of the kidney called?

1. arcuate nephrons
2. juxtamedullary nephrons
3. interlobular nephrons
4. convoluted nephrons
5. cortical nephrons Answer: B

120. Which capillaries branch from efferent arterioles of cortical nephrons and which branch from efferent arterioles of juxtamedullary nephrons?

1. cortical and juxtamedullary, respectively
2. peritubular and vasa recta, respectively
3. arcuate and peritubular, respectively
4. interlobar and interlobular, respectively
5. vasa recta and interlobular, respectively Answer: B

121. What are the specialized cells of the juxtaglomerular apparatus in the distal tubule called?

1. baroreceptors
2. juxtaglomerular cells
3. afferent endothelial cells
4. macula densa
5. granular cells Answer: D

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122. What are the specialized cells of the juxtaglomerular apparatus in the afferent arteriole (and, to a lesser extent, the efferent arteriole) called?

1. baroreceptors
2. macula densa
3. vasa recta
4. apparatus cells
5. granular cells Answer: E

123. Which layer of the filtration barrier in Bowman's capsule is the primary barrier to the movement of protein from the capillary?

1. endothelial cell
2. epithelial cell
3. macula densa
4. granular cell
5. basement membrane Answer: E

124. Under normal conditions, the osmotic pressure gradient across the glomerular capillaries tends to move water

1. against its concentration gradient.
2. into the filtrate.
3. back into the capillaries.
4. into the collecting duct.
5. into the parenchyma. Answer: C

125. Which of the four Starling forces for glomerular filtration is incorrectly paired with the direction it favors (filtration or absorption)?

1. glomerular capillary hydrostatic pressure : filtration
2. Bowman's capsule oncotic pressure : filtration
3. glomerular capillary oncotic pressure : absorption
4. glomerular capillary osmotic pressure : filtration
5. Bowman's capsule hydrostatic pressure : absorption Answer: D

126. Given a GFR of 100 mL/min, and a plasma concentration of solute of 10 mg/mL, what is the filtered load of this solute?

1. 1 g/mL
2. 1000 mL/min
3. 100 mg/dL
4. 100 mg/mL
5. 1000 mg/min Answer: E

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127. When carrier proteins are saturated, they are said to be working at what?

1. active reabsorptive state
2. increased capacity
3. diminished capacity
4. increased affinity
5. transport maximum Answer: E

128. The clearance of          provides a measure of renal plasma flow rate.

A) PAH B) glucose C) inulin D) myoglobin E) urea Answer: A

129. The clearance of what substance, which is not produced in the body but must be injected, provides a measure of glomerular filtration rate?

A) PAH B) inulin C) urea D) glucose E) creatinine Answer: B

130. The clearance of what substance, a natural by-product of muscle metabolism, provides a non-invasive estimate of glomerular filtration rate?

A) urea B) inulin C) glucose D) PAH E) creatinine Answer: E

131. In terms of controlling micturition, the somatic nervous system innervates the    , the parasympathetic nervous system innervates the     , and the sympathetic nervous system innervates the               .

1. bladder skeletal muscle : bladder smooth muscle : external urethral sphincter
2. internal urethral sphincter : external urethral sphincter : detrusor muscle
3. bladder : micturition reflex : external urethral sphincter
4. external urethral sphincter : detrusor muscle : internal urethral sphincter
5. internal urethral sphincter : detrusor muscle : external urethral sphincter Answer: D

132. The micturition reflex is activated by the stretch of the bladder, which activates what?

1. somatic afferents
2. stretch receptors
3. parasympathetic efferents
4. parasympathetic afferents
5. sympathetic afferents Answer: B

133. The vasculature of the kidneys is quite unique in its organization. This organization has consequences for the control of the renal vasculature. Describe the vasculature of the kidneys, including the consequences of the

high resistance of the efferent arteriole.

134. In order for a nephron to act as a filter, the plasma must be able to exit the vasculature. Describe the balance of Starling's forces across the glomerular capillaries that drives the movement of plasma and the pathway

that plasma takes as it becomes filtrate.

135. In spite of the large volume of fluid that enters the kidneys every day, glomerular filtration rate (GFR) is highly regulated to minimize changes that might alter urine output. Describe the intrinsic mechanisms involved in the maintenance of GFR in the presence of a stimulus that would elevate GFR.
136. Glomerular filtration rate is controlled by both intrinsic and extrinsic mechanisms. Describe the extrinsic mechanism with particular emphasis on how it would respond to a hemorrhage.
137. Glucose is an important component of the blood that is usually completely reabsorbed (there is no glucose in the urine). Outline the process whereby glucose is transported across the tubular epithelial cells, including

the concepts of transport maximum and renal threshold.

138. Although some of the mechanisms are the same, the functions of the proximal and distal tubules are quite different. Compare and contrast the structural differences between epithelial cells in the proximal and distal tubes.
139. Ultimately, our ability to assess the function of the kidneys involves measuring what is excreted in urine. Describe the methods used to assess the function of the kidneys (glomerular filtration rate [GFR]), including the calculations and ions involved in that assessment.

140. Explain how diabetes mellitus causes polyuria.
141. In order for urine to be eliminated, the process of micturition must be initiated. Describe the process whereby urine generated by the kidneys reaches the bladder and how that urine is voided from the bladder.
142. In response to a loss of blood, the sympathetically-induced (increase / decrease) in renal vascular resistance will cause glomerular filtration rate to (increase / decrease).
143. The (tubular epithelial cell / peritubular capillary endothelial cell) forms the primary barrier for reabsorption of most solutes.
144. If solute A is actively transported across the basolateral membrane into the epithelial cell and then passively crosses the apical membrane, then is A (reabsorbed / secreted) across this epithelium.
145. If solute B moves passively across the basolateral membrane and is actively transported out of the epithelial cell across the apical membrane, then B is (reabsorbed / secreted) across this epithelium.
146. If solute C moves passively across the basolateral membrane and is actively transported into the epithelial cell across the apical membrane, then C is (reabsorbed / secreted) across this epithelium.
147. Compared to the distal tubule, the proximal tubule utilizes (more / less) ATP.
148. Compared to the distal tubule, the proximal tubule has (tighter / leakier) tight junctions.