Ch 19 MC But No T/f

1) Plasma can gain solutes and/or water from which of the following? A) gastrointestinal tract only B) renal tubules only C) bone only D) both the gastrointestinal tract and bone E) both the gastrointestinal tract and renal tubules

2) Movement across which of the following generally results in a net loss of solutes and/or water? A) gastrointestinal tract only B) skin only C) renal tubules only D) both the gastrointestinal tract and renal tubules E) both skin and renal tubules

3) A substance is in negative balance when ________. A) it enters plasma at the same rate it exits plasma B) it enters plasma at a greater rate than it exits plasma C) it exits plasma at a greater rate than it enters plasma D) its usage by cells is decreased E) its production by cells is increased

4) The regulation of water and ion excretion occurs primarily within the ________. A) proximal tubules only B) late distal tubules only C) collecting ducts only D) both proximal tubules and late distal tubules E) both collecting ducts and late distal tubules

5) The regulation of sodium and water balance in the kidneys occurs primarily through the unique action of which cells in the distal tubules and collecting ducts? A) intercalated cells B) principal cells C) mesangial cells D) granular cells E) podocytes

6) The regulation of acid-base balance in the kidneys occurs primarily through the unique action of which cells in the distal tubules and collecting ducts? A) intercalated cells B) principal cells C) mesangial cells D) granular cells E) podocytes

7) Which of the following is a source of water input? A) gastrointestinal tract only B) renal tubules only C) metabolism only D) both gastrointestinal tract and metabolism E) both the gastrointestinal tract and renal tubules

8) What is the force that moves water out of the distal tubules and collecting ducts? A) the passive regulated movement through Na+/H2O transporter B) the passive unregulated movement along the paracellular pathway C) the active transport of water D) an osmotic gradient E) an alteration in temperature

9) If a person is normovolemic and consumes a large quantity of a hyperosmotic solution, it will ________. A) have no effect on cell osmolarity and thereby cell size B) cause cells to shrink due to an increase in the osmolarity of extracellular fluid C) cause cells to swell due to an increase in the osmolarity of extracellular fluid D) cause cells to swell due to a decrease in the osmolarity of extracellular fluid E) cause cells to shrink due to a decrease in the osmolarity of extracellular fluid

10) Which of the conditions listed below is NOT indicative of a decrease in plasma osmolarity? A) headache B) nausea C) confusion D) neural hyperexcitability E) seizure

11) Kidneys compensate for changes in plasma volume and osmolarity by adjusting the rate of water ________. A) reabsorption only B) secretion only C) resorption only D) reabsorption and secretion E) secretion and resorption

12) Which of the following mechanisms is NOT important in the maintenance of the osmotic gradient within the proximal tubule that drives water movement? A) cotransport of chloride B) cotransport of amino acids C) cotransport of glucose D) active reabsorption of sodium E) diffusion of urea

13) Which of the following accurately describes the thick ascending limb of the loop of Henle? A) permeable to water in the presence of specific hormones B) permeable to water and does NOT contain Na+/K+/Cl- cotransporters C) impermeable to water and does NOT contain Na+/K+/Cl- cotransporters D) impermeable to water and contains Na+/K+/Cl- cotransporters E) permeable to water and contains Na+/K+/Cl- cotransporters

14) In the ascending limb of the loop of Henle, the filtrate will always be ________. A) in equilibrium with the the medullary interstitial fluid B) of a lower osmolarity than the medullary interstitial fluid C) a higher osmolarity than the medullary interstitial fluid D) the same osmolarity as the filtrate in the descending limb of the loop of Henle E) a higher osmolarity than the filtrate in the descending limb of the loop of Henle

15) The osmotic gradient in the medullary region of the kidneys is established and maintained by which of the following? A) Na+/K+/Cl- cotransporters in the ascending limb of the loop of Henle B) Na+/K+/Cl- cotransporters in the descending limb of the loop of Henle C) efflux of water from the ascending limb of the loop of Henle D) efflux of water from the descending limb of the loop of Henle E) efflux of Na+ from the descending limb of the loop of Henle

16) Which of the following comparisons of osmolarity within the kidneys is INCORRECT? A) The fluid in the proximal tubule is iso-osmotic with cortical interstitial fluid. B) Osmolarity of the ascending limb of the loop of Henle is greater than that of the descending limb. C) Osmolarity of the descending limb of the loop of Henle is iso-osmotic with the medullary interstitial fluid. D) The osmolarity of plasma in the vasa recta varies with its location in the renal medulla. E) Osmolarity of fluid in the proximal tubule is greater than the osmolarity of fluid in the end of the loop of Henle as it enters the distal tubule.

17) A long loop of Henle would result in which of the following? A) a higher osmolarity in the deeper regions of the renal medulla and the ability to produce a more concentrated urine B) a lower osmolarity in the deeper regions of the renal medulla and the ability to produce a more concentrated urine C) a higher osmolarity in the deeper regions of the renal medulla and the ability to produce a more dilute urine D) a lower osmolarity in the deeper regions of the renal medulla and the ability to produce a more dilute urine E) a higher osmolarity in the renal cortex and the ability to produce a more dilute urine

18) The hormone-induced increases in water permeability of the distal tubule and collecting ducts is mediated by a(n) ________. A) increase in aquaporin-2 activity B) increase in aquaporin-3 activity C) increase in paracellular permeability D) decrease in ʺtightnessʺ of tight junctions E) decrease in paracellular permeability

19) What keeps the capillaries of the vasa recta from dissipating the medullary osmotic gradient? A) the smooth muscle cells contain Na+/K+/Cl- cotransporters B) the smooth muscle cells are impermeable to water and ions C) the vascular endothelial cells are impermeable to water and ions D) capillary blood enters and exits the medulla at a similar osmolarity E) the vascular endothelial cells contain Na+/K+/Cl- cotransporters

20) If nothing else is removed from the filtrate once it reaches the late distal tubules, the urine excreted would have which of the following properties? A) devoid of ions and large volume B) high osmolarity and low volume C) low osmolarity and low volume D) low osmolarity and large volume E) high osmolarity and large volume

21) What solute maintains the medullary interstitial fluid osmotic gradient? A) urea B) sodium ions C) potassium ions D) water E) glucose

22) Which of the following correctly describes water movement across the epithelial cells lining the collecting duct? A) Water can permeate the lipid bilayer at all times. B) Water can permeate the phospholipid bilayer only in the presence of ADH. C) Water can permeate the phospholipid bilayer only in the presence of aldosterone. D) Water can permeate the apical membrane through aquaporin-2 and the basolateral membrane through aquaporin-3, but aquaporin-2 is only present in the presence of ADH. E) Water can permeate the basolateral membrane through aquaporin-2 and the apical membrane through aquaporin-3, but aquaporin-2 is only present in the presence of aldosterone.

23) A person must void what volume of urine per day? A) 0 mL B) 15 mL C) 120 mL D) 440 mL E) 1200 mL

24) Which of the following limits the volume of the obligatory water loss? A) diameter of the loop of Henle B) the osmolarity at the early portion of the distal tubule C) the maximal osmolarity of the medullary osmotic gradient D) the water permeability of the the collecting ducts E) the water permeability of the distal tubule

25) In the early portion of the collecting duct (in cortical interstitial fluid), an increase in water permeability will result in a(n) ________. A) increase in filtrate volume B) decrease in filtrate volume C) movement of water into the duct D) transport of sodium out of the tubule E) efflux of urea from the tubule

26) Where is ADH released from? A) distal tubule B) collecting duct C) pancreas D) posterior pituitary E) anterior pituitary

27) Antidiuretic hormone binds to receptors on ________ cells in the collecting ducts and distal tubules where it ________. A) granular : causes vesicles with aquaporin-2 to insert into the apical membrane B) intercalated : causes vesicles with aquaporin-3 to insert into the apical membrane C) intercalated : causes vesicles with aquaporin-2 to insert into the basolateral membrane D) principal : causes insertion of aquaporin-2 into the apical membrane E) principal : causes vesicle with aquaporin-3 to insert into the apical membrane

28) The intracellular event that stimulates the insertion of aquaporin-2 into the apical membranes of principal cells is driven by ________. A) sodium B) guanylate cyclase C) cGMP D) protein kinase C E) protein kinase A

29) At high concentrations of antidiuretic hormone, the extent of water reabsorption in the collecting ducts is ________, causing urine output to ________. A) high : decrease B) low : decrease C) high : increase D) low : increase E) unaffected : remain unchanged

30) What is the strongest stimulus for the release of antidiuretic hormone from the posterior pituitary? A) decrease in plasma osmolarity B) decrease in blood pressure C) increase in plasma osmolarity D) increase in blood pressure E) decrease in sodium content of the blood

31) Which of the following is NOT one of the stimuli that will result in the release of antidiuretic hormone? A) decreased blood pressure B) decreased plasma volume C) increased osmolarity D) decreased plasma potassium E) angiotensin II

32) In diabetes insipidus, blood levels of ________ are decreased causing an increase in ________. A) insulin : glucose in the urine B) aldosterone : sodium in the urine C) aldosterone : potassium in the urine D) ADH : urine volume E) ADH : plasma volume

33) Which of the following diseases is associated with decreased responsiveness of the renal tubules to ADH? A) diabetes mellitus type 1 B) diabetes mellitus type 2 C) central diabetes insipidus D) nephrogenic diabetes insipidus E) diabetic nephropathy

34) Which of the following is a synonym for polyuria? A) polydipsia B) antidipsia C) diuresis D) antidiuresis E) hyperemia

35) In diabetes insipidus, why does polyuria occur? A) a lack of ADH decreases water reabsorption B) an increase in aldosterone increases water reabsorption C) glucose transporters in the renal tubules become saturated D) a lack of angiotensin II decreases thirst E) a lack of insulin decreases water permeability of the renal tubules

36) Which of the following conditions would be associated with hypernatremia? A) increased plasma sodium B) decreased plasma osmolarity C) increased plasma potassium D) decreased plasma volume E) hypotension

37) Which of the following statements on sodium movement in the renal tubules is true? A) Sodium is actively transported across the basolateral membrane of both the proximal and distal tubule. B) Sodium is actively secreted from the collecting duct. C) Sodium is actively secreted from the proximal tubule. D) Sodium reabsorption follows water reabsorption in all segments of the renal tubules. E) Sodium channels are located on the basolateral membrane of principal cells.

38) In the renal tubules, where is the Na+/K+ pump located? A) in the basolateral membrane of the proximal tubules B) in the apical membrane of the descending limb of the loop of Henle C) in the apical membrane of the collecting ducts D) in both the apical and basolateral membranes of principal cells E) in both the apical and basolateral membranes of intercalated cells

39) Which of the following best describes sodium movement in the proximal tubule? A) Sodium is transported across the basolateral membrane by the Na+/K+ pump and across the apical membrane by diffusion through sodium channels. B) Sodium is transported across the apical membrane by the Na+/K+ pump and across the basolateral membrane by diffusion through sodium channels. C) Sodium is transported across the basolateral membrane by the Na+/K+ pump and across the apical membrane by secondary active transport. D) Sodium is transported across the apical membrane by the Na+/K+ pump and across the basolateral membrane by secondary active transport. E) Sodium is transported across the apical membrane by the Na+/K+ pump and across the basolateral membrane by facilitated diffusion.

40) Which of the following best describes sodium movement in the distal tubule? A) Sodium is transported across the basolateral membrane by the Na+/K+ pump and across the apical membrane by diffusion through sodium channels. B) Sodium is transported across the apical membrane by the Na+/K+ pump and across the basolateral membrane by diffusion through sodium channels. C) Sodium is transported across the basolateral membrane by the Na+/K+ pump and across the apical membrane by facilitated diffusion. D) Sodium is transported across the apical membrane by the Na+/K+ pump and across the basolateral membrane by facilitated diffusion. E) Sodium is transported across the apical membrane by the Na+/K+ pump and across the basolateral membrane by secondary active transport.

41) Aldosterone is released from the ________ in response to ________. A) adrenal medulla : decreases in plasma sodium B) adrenal cortex : increases in plasma potassium C) posterior pituitary : increases in plasma osmolarity D) pancreas : increases in plasma glucose E) macula densa : increased flow of tubular fluid in the distal tubule

42) Which of the following is an effect of aldosterone on principal cells? A) decreased number of open Na+ and K+ channels in the basolateral membrane B) decreased number of Na+/K+ pumps in the basolateral membrane C) increased number of open Na+ and K+ channels in the basolateral membrane D) increased number of open Na+ and K+ channels in the apical membrane E) increased number of Na+/K+ pumps in the apical membrane

43) Which of the following is associated with actions of aldosterone on principal cells? A) increased sodium secretion B) increased potassium secretion C) decreased blood pressure D) decreased plasma osmolarity E) increased calcium reabsorption

44) Renin is released by ________ cells of the ________. A) principal : afferent arteriole B) granular : afferent arteriole C) principal : distal tubule D) granular : distal tubule E) intercalated : afferent arteriole

45) What enzyme converts angiotensinogen into angiotensin I. A) Carbonic anhydrase B) Atrial natriuretic peptide C) Angiotensin converting enzyme (ACE) D) Renin E) Mucin

46) What enzyme converts angiotensin I into angiotensin II. A) Carbonic anhydrase B) Atrial natriuretic peptide C) Angiotensin converting enzyme (ACE) D) Renin E) Mucin

47) Which of the following is NOT one of the functions of angiotensin II? A) vasoconstriction B) stimulate aldosterone secretion C) stimulate antidiuretic hormone (ADH) secretion D) increased thirst E) stimulate renin secretion

48) Angiotensin II acts directly in the hypothalamus to stimulate what? A) an increase in thirst B) the release of oxytocin C) an increase in body temperature D) the release of aldosterone E) a systemic increase in blood pressure

49) Which of the following conditions is NOT responsible for stimulating the release of renin? A) decreased pressure within the afferent arteriole B) increase in sympathetic nerve activity C) decrease in sodium and chloride in the distal tubule D) increased glomerular filtration rate E) decreased mean arterial pressure

50) Angiotensinogen is synthesized by what organ? A) kidney B) bone marrow C) liver D) adrenal gland E) pituitary gland

51) What role do the macula densa cells have in controlling renin release? A) They release renin in response to an increase in mean arterial pressure. B) They release renin in response to a decrease in mean arterial pressure. C) They detect changes in the pressure of afferent arterioles, and communicate these changes to juxtaglomerular cells, which secrete renin. D) They detect changes in the pressure of efferent arterioles, and communicate these changes to juxtaglomerular cells, which secrete renin. E) They detect changes in the amount of sodium and chloride in the distal tubules, and communicate these changes to juxtaglomerular cells, which secrete renin.

52) What stimulates atrial natriuretic peptide release? A) distension of the atrial wall due to an increase in blood pressure B) distension of the atrial wall due to an increase in plasma volume C) changes in the concentration of sodium in the blood of the atrium D) changes in the concentration of potassium in the blood of the atrium E) renin

53) Which of the following conditions will NOT be stimulated by atrial natriuretic peptide? A) increased sodium excretion B) efferent arteriole constriction C) afferent arteriole constriction D) increased glomerular filtration rate E) increased glomerular capillary pressure

54) Atrial natriuretic peptide causes which of the following effects in principal cells? A) decreased activity of the Na+/K+ pump in the basolateral membrane B) efferent arteriole dilation C) afferent arteriole constriction D) decreased number of open sodium channels in the apical membrane E) increase in glomerular filtration rate

55) The extent of potassium excretion is regulated primarily by the ________. A) amount filtered by the basement membrane of the glomerular capillaries B) amount reabsorbed into the proximal tubule C) amount secreted into the proximal tubule D) amount reabsorbed in the distal tubule E) amount secreted into the distal tubule

56) Hyperkalemia refers to an excess of what? A) water B) sodium C) potassium D) calcium E) chloride

57) Which of the following is NOT a symptom of hyperkalemia? A) diarrhea B) hypotension C) cardiac arrhythmias D) muscle cramps E) nausea

58) Which of the following is FALSE of the renal handling of potassium? A) Potassium is freely filtered at the glomerulus. B) Potassium is only reabsorbed in the proximal tubule. C) Potassium is reabsorbed and secreted in the distal tubule. D) Potassium is only secreted in the collecting duct. E) Potassium secretion is regulated by aldosterone.

59) The reabsorption of potassium in the proximal tubule requires which of the following? A) potassium channel activity in the apical membrane B) potassium channel activity in the basolateral membrane C) Na+/K+ pump activity in the apical membrane D) stimulation by aldosterone E) stimulation by angiotensin II

60) Potassium enters the epithelial cells of the proximal tubule by which of the following mechanisms? A) Na+/K+ pumps in the basolateral membrane B) Na+/K+ pumps in the apical membrane C) potassium channels in the basolateral membrane D) Na+/K+ cotransport in the apical membrane E) K+/HCO3- countertransport in the apical membrane

61) The secretion of potassium in the distal tubule requires which of the following? A) Na+/K+ pump activity in the apical membrane B) potassium channel activity in the basolateral membrane C) potassium channel activity in the apical membrane D) stimulation by ADH E) stimulation by angiotensin II

62) Which of the following best describes the effect of aldosterone on renal handling of potassium? A) Aldosterone enhances potassium reabsorption in the proximal tubule by increasing the number of Na+/K+ pumps in the basolateral membrane and increasing the number of potassium channels in the apical membrane. B) Aldosterone enhances potassium reabsorption in the distal tubule by increasing the number of Na+/K+ pumps in the apical membrane and increasing the number of potassium channels in the basolateral membrane. C) Aldosterone enhances potassium secretion in the proximal tubule by increasing the number of Na+/K+ pumps in the apical membrane and increasing the number of potassium channels in the basolateral membrane. D) Aldosterone enhances potassium secretion in the distal tubule by increasing the number of Na+/K+ pumps in the apical membrane and increasing the number of potassium channels in the basolateral membrane. E) Aldosterone enhances potassium secretion in the distal tubule by increasing the number of Na+/K+ pumps in the basolateral membrane and increasing the number of potassium channels in the apical membrane.

63) Which of the following structures is NOT involved in the regulation of plasma calcium? A) skin B) skeletal muscle C) kidneys D) bone E) gastrointestinal tract

64) The bone can supply calcium to the plasma by what process? A) filtration B) reabsorption C) calcification D) resorption E) ossification

65) Which of the following statements about renal handling of calcium is FALSE? A) Calcium that is bound to plasma proteins is NOT filtered. B) Most calcium is reabsorbed in the proximal tubule. C) Calcium is reabsorbed in the thick ascending limbs of the loop of Henle. D) Calcium is reabsorbed in the distal tubule. E) Calcium secretion is regulated by parathyroid hormone.

66) Which of the following is NOT one of the responses that occur following an increase in parathyroid hormone? A) increased reabsorption of calcium in the ascending limb of the loop of Henle B) increased reabsorption of calcium in the distal tubules C) activation of 1, 25-dihydroxy vitamin D3 increases calcium absorption in the gastrointestinal tract D) increased reabsorption of calcium in the proximal tubules E) resorption of bone calcium

67) A decrease in plasma calcium will initiate an increase in the release of which of the following? A) parathyroid hormone only B) calcitonin only C) 1, 25-dihydroxy vitamin D3 only D) both parathyroid hormone and calcitonin E) both parathyroid hormone and 1, 25-dihydroxy vitamin D3

68) Which of the following hormones are lipophilic? A) 1, 25-dihydroxy vitamin D3 only B) parathyroid hormone only C) calcitonin only D) both parathyroid hormone and 1, 25-dihydroxy vitamin D3 E) both parathyroid hormone and calcitonin

69) Which of the following hormones is a steroid? A) angiotensin II B) antidiuretic hormone C) aldosterone D) parathyroid hormone E) calcitonin

70) Exposure of the skin to sunlight converts ________ to vitamin D3. A) calcium B) calcitriol C) 25-OH D3 D) cholesterol E) 7-dehydrocholesterol

71) The last step to synthesis of 1, 25-dihydroxy vitamin D3 occurs in what organ? A) kidney B) liver C) skin D) gastrointestinal tract E) brain

72) What hormone decreases plasma calcium levels? A) calcitonin only B) 1, 25-dihydroxy vitamin D3 only C) parathyroid hormone only D) both calcitonin and 1, 25-dihydroxy vitamin D3 E) both calcitonin and parathyroid hormone

73) The effects of antidiuretic hormone (ADH) are not restricted to regulating water movement; it also affects sodium reabsorption by ________. A) increasing the synthesis of sodium channels in principal cells B) increasing the synthesis of sodium channels in intercalated cells C) decreasing the synthesis of sodium channels in intercalated cells D) decreasing the synthesis of sodium channels in principal cells E) increasing the synthesis of Na+/K+ pumps in principal cells

74) Angiotensin II and atrial natriuretic peptide are able to alter the reabsorption of water through a similar pathway that involves altered ________. A) integration of aquaporin-3 into the membrane B) release of antidiuretic hormone (ADH) C) Na+/K+ pump activity in the intercalated cells D) Na+/K+ pump activity in the principal cells E) sodium channel expression on the apical membrane

75) Which of the following is NOT a response to hemorrhage? A) decreased renin secretion B) increased sympathetic activity C) increased angiotensin II production D) increased ADH release E) increased epinephrine secretion

76) Which of the following does NOT occur as a consequence of the increased release of renin and its effects on other hormones? A) vasoconstriction B) thirst C) sodium reabsorption D) increased heart rate E) water reabsorption

77) The hemorrhage-induced decrease in blood flow to the kidneys will ________. A) decrease the release of renin B) increase glomerular filtration rate C) increase the production of erythrocytes D) increase the release of atrial natriuretic peptide E) increase the production of leukocytes

78) Which of the following is NOT one of the effects of changes in pH on the body? A) alterations in protein function B) alterations in central nervous system activity C) alterations in potassium homeostasis D) alteration in water balance E) alterations in cardiac rhythm

79) The activity of the respiratory system can increase pH by ________. A) a hyperventilation-induced increase in PCO2 B) a hypoventilation-induced increase in PCO2 C) a hyperventilation-induced decrease in PCO2 D) a hypoventilation-induced decrease in PCO2 E) increasing amount of carbonic acid in the blood

80) What is the normal range of blood pH? A) 6.80-7.20 B) 6.90-7.10 C) 6.75-6.95 D) 7.20-7.60 E) 7.35-7.45

81) During hyperventilation, why do some people detect a tingling sensation in their hands and feet? A) due to hyperexcitability of afferent neurons B) due to a decrease in blood flow to the distal extremities C) due to a decrease in carbon dioxide in blood D) due to an increase in carbon dioxide in blood E) due to widespread release of catecholamines

82) Which of the following is NOT a metabolic disturbance that can result in a metabolic acidosis? A) high protein diet B) high fat diet C) heavy exercise D) excessive vomiting E) severe diarrhea

83) What is the most rapid defense against changes in blood pH? A) respiratory compensation B) buffering of hydrogen ions C) renal compensation D) cardiac compensation E) hepatic compensation

84) How does severe diarrhea cause a metabolic acidosis? A) production of bicarbonate B) production of hydrogen ions C) loss of hydrogen ions D) loss of phosphate E) loss of bicarbonate

85) How does severe vomiting cause a metabolic alkalosis? A) production of bicarbonate B) production of hydrogen ions C) loss of hydrogen ions D) loss of phosphate E) loss of bicarbonate

86) Which of the following ions acts as a buffer to minimize changes in intracellular pH? A) phosphate B) bicarbonate C) chloride D) potassium E) sodium

87) The role of a buffer is to ________. A) reduce the reabsorption of hydrogen ions in the kidneys B) limit the change in pH with changing hydrogen ion concentrations C) reduce the secretion of hydrogen ions in the kidneys D) reduce the secretion of bicarbonate ions in the kidneys E) enhance the ability of an increase in hydrogen ions to increase pH

88) What is the secondary defense against changes in pH that requires minutes to be activated? A) respiratory compensation B) buffering of hydrogen ions C) renal compensation D) cardiac compensation E) hepatic compensation

89) Respiratory compensation for changes in pH are originated by ________. A) proprioceptors B) baroreceptors C) central chemoreceptors D) peripheral chemoreceptors E) directly affecting the activity of the diaphragm

90) When an increase in hydrogen ions remains after one hour, this will lead to a(n) ________. A) decrease in bicarbonate reabsorption in the kidneys B) increased hydrogen reabsorption in the kidneys C) increase in bicarbonate secretion in the kidneys D) increase in hydrogen ion secretion from the kidneys E) failure of the kidneys to filter any more hydrogen ions

91) Which of the following is an effect of the transporters in the proximal tubules? A) secretion of urea B) secretion of potassium C) reabsorption of hydrogen D) secretion of sodium E) reabsorption of bicarbonate

92) In the basolateral membrane of proximal tubular cells, bicarbonate is moved out of the cells by ________. A) K+/HCO3- countertransporters only B) HCO3-/Cl- countertransporters only C) Na+/HCO3- cotransporters only D) both K+ HCO3- and HCO3- /CI- countertransporters E) both HCO3- /CI- countertransporters and Na+ / HCO3- cotransporters

93) In the proximal tubule, hydrogen ions are transported into the filtrate by ________. A) Na+/H+ countertransporters only B) H+ primary active transporters only C) H+/Cl- cotransporters only D) both Na+/H+ countertransporters and H+ primary active transporters E) both Na+/H+ countertransporters and H+/Cl- cotransporters

94) Bicarbonate crosses the apical membrane of the proximal tubule by ________. A) HCO3-/Cl- countertransporters B) Na+/HCO3- cotransporters C) conversion to carbon dioxide D) HCO3- active transporters E) Na+/HCO3- countertransporters

95) Which of the following transporters is NOT found embedded in the membrane of the intercalated cells of the late distal tubule and collecting ducts? A) HCO3-/Cl- countertransporters in the basolateral membrane B) Na+/HCO3- cotransporters in the basolateral membrane C) chloride channels in the basolateral membrane D) H+ pumps in the apical membrane E) K+/H+ countertransporters in the apical membrane

96) What is the normal source of the new bicarbonate in the late distal tubule and collecting ducts? A) carbon monoxide produced in the distal tubule B) catabolism of lysine C) catabolism of glutamine D) carbon dioxide from the system circulation E) carbon dioxide produced by the tubule cells

97) Under severe acidic conditions, the proximal tubules can convert ________ into bicarbonate. A) glutamate B) carbon monoxide C) lysine D) glutamine E) glycine

98) Hydrogen ions in the filtrate within the collecting ducts are buffered by the presence of ________. A) phosphate B) bicarbonate C) carbon dioxide D) glutamine E) proteins

99) In order to compensate for a hyperventilation, the ________. A) kidneys decrease the reabsorption of bicarbonate B) kidneys increase the conversion of glutamine to bicarbonate C) kidneys increase the secretion of hydrogen ions D) lungs increase ventilation rate E) kidneys increase the reabsorption of hydrogen ions

100) Which of the following is NOT a compensation that would occur in response to a metabolic acidosis? A) increased excretion of hydrogen ions B) increased ventilation C) decreased tidal volume D) increased bicarbonate production E) increased conversion of glutamine to bicarbonate

101) A patient is exhibiting several signs of acid-base imbalance. Blood tests reveal that blood pH is 7.3, and bicarbonate and carbon dioxide levels in blood are both low. What is the state of this patient? A) metabolic acidosis with respiratory compensation B) respiratory acidosis with renal compensation C) metabolic alkalosis with respiratory compensation D) respiratory alkalosis with renal compensation E) blood pH is normal

102) A patient is exhibiting several signs of acid-base imbalance. Blood tests reveal that blood pH is 7.5, and bicarbonate and carbon dioxide levels in blood are both low. What is the state of this patient? A) metabolic acidosis with respiratory compensation B) respiratory acidosis with renal compensation C) metabolic alkalosis with respiratory compensation D) respiratory alkalosis with renal compensation E) blood pH is normal