RENAL - ACID BASE – ADRENAL PHYSIOLOGY

MCQS

22 nd Dec 2011

1. Secretion of K+ by the distal tubule will be decreased by which of the following?

a. Metabolic alkalosisb. A high K+ dietc. Hyperaldosteronismd. Spironolactone administration

2. A woman has a plasma osmolarity of 300 mosm/. The correct diagnosis is

a. SIADHb. Water deprivationc. Central diabetes insipidusd. Nephrogenic diabetes insipidus

3. The following blood gas picture is most consistent with: pH = 7.56; pCO2 = 20mmHg; pO2 = 100mmHg; bicarb = 25mmol/

a. Emphysemab. Prolonged vomitingc. Bicarbonate ingestiond. 2 week residence at high altitude

4. The principal buffer in interstitial fluid is which of the following?

a. Carbonic acidb. Hbc. Phosphated. Compounds containing histidine

5. Regarding absorption of Na+ in the proximal tubule, which of the following is true?

a. The proximal tubule reabsorbs 80% of the filtered sodium loadb. Absorption of Na+ causes increasing hypertonicity in the tubule lumenc. Absorption is powered by the Na+/H+ ATPased. Shares a common carrier with glucose

6. Which of the following agents does not cause contraction of the mesangial cells in the glomerulus?

a. Angiotensin IIb. Noradrenalinec. Histamined. Dopamine

7. The lower pH limit of the urine is which of the following?

a. 1.0b. 3.5c. 4.5d. 6.0

8. ADH (vasopressin) secretion is increased by which of the following?

a. Alcoholb. Carbamazepinec. extracellular fluid volumed. Angiotensin I

9. With respect to the counter current system, which is false?

a. Solutes diffuse out of vessels conducting blood toward the cortexb. Water diffuses out of ascending vesselsc. Water diffuses into the collecting ductsd. Counter current exchange is passive and can operate even if counter

current multiplication ceases

10. Which of the following is most permeable to water?

a. Thin ascending Loop of Henleb. Distal convoluted tubulec. Thin descending Loop of Henled. Thick ascending limp of Loop of Henle

11. pH 7.16; pCO2 = 24mmHg; pO2 = 100mmHg; bicarbonate = 6mmol/; K+ = 3.4mmol/

Which of the following is MOST likely to cause the above picture

a. Cyanide poisoningb. Hyperventilationc. Liquorice ingestiond. Addison’s disease

12. Metabolic alkalosis can be caused by all of the following EXCEPT

a. Hyperaldosteronismb. Hyperventilationc. Hypokalaemiad. Volume depletion

13. The consumption of oxygen by the kidney, which is incorrect?

a. Decreases as blood flow increasesb. Is regulated by erythropoietinc. Remains constant as blood flow increasesd. Is greatest in the medulla

14. An increase in the concentration of plasma potassium causes an increase in which of the following?

a. Release of reninb. Secretion of aldosteronec. Secretion of ADHd. Release of natriuretic hormone

15. Which of the following would increase GFR?

a. Constriction of the afferent arterioleb. A decrease in afferent arteriolar pressurec. Compression of the renal capsuled. A decrease in the concentration of plasma protein

16. The greatest amount of hydrogen ion secreted by the proximal tubule is associated with which of the following?

a. Excretion of potassium ionb. Reabsorption of calcium ionc. Reabsorption of bicarbonate iond. Reabsorption of phosphate ion

17. All of the following comparisons between the distal nephron and the proximal tubule are correct EXCEPT

a. The distal nephron is less permeable to hydrogen ion than is the proximal tubule

b. The distal nephron has a more negative intraluminal potential than does the proximal tubule

c. The distal nephron secretes more potassium than does the proximal tubule

d. The distal nephron secretes more hydrogen ion than does the proximal tubule

18. Urinary volume is increased by all of the following EXCEPT

a. Sympathetic stimulationb. Diabetes insipidusc. Increased renal arterial pressured. Infusion of mannitol

19. Which one of the following statements about aldosterone is correct?

a. It produces its effect by activating cAMPb. It produces its effects by increasing membrane permeability to

potassiumc. It causes an increased reabsorption of hydrogen iond. It is secreted in response to an increase in BP

20. The ability of the kidney to excrete a concentrated urine will increase if

a. The permeability of the proximal tubule to water decreasesb. The rate of blood flow through the medulla decreasesc. The rate of flow through the Loop of Henle increasesd. The activity of the Na-K pump in the Loop of Henle decreases

21. Which of the following returns closest to normal during chronic respiratory acidosis?

a. Arterial PCO2b. Arterial PO2c. Plasma concentration of bicarbonated. Arterial concentration of hydrogen ion

22. Renal correction of hyperkalaemia will result in which of the following?

a. Alkalosisb. Increased secretion of HCO3- c. Acidosisd. Increased excretion of Na+

23. In controlling the synthesis and secretion of aldosterone – which of the following factors is LEAST important?

a. Reninb. Angiotensin IIc. ACTHd. Concentration of plasma K+

24. Ammonia is an effective and important urinary buffer for which of the following reasons?

a. Its production in the kidney during chronic alkalosisb. The walls of the renal tubules are impermeable to NH3 c. The walls of the renal tubules are impermeable to NH4

+

d. Its acid base reaction has a low pKa

25. pH 7.67, PO2 120mmHg on O2; PCO2 60mmHg and bicarbonate 36mmol/l on a blood gas is indicative of

a. Respiratory alkalosisb. Mixed metabolic and respiratory alkalosisc. Respiratory acidosisd. Metabolic alkalosis

26. The TMg for women (transport maximum for glucose) in the kidney is about

a. 75mg/minb. 100mg/minc. 150mg/mind. 300mg/min

27. A loss of function mutates in the gene of which of the following proteins is associated with nephrogenic diabetes insipidus

a. Aquaporin -1b. Aquaporin -2c. Aquaporin -3d. Aquaporin -4

28. Dehydration increases the plasma concentration of all of the following EXCEPT

a. Vasopressinb. Angiotensin IIc. Noradrenalined. Atrial natriuretic peptide

29. Calculate the anion gap from these results –Na+ 142; K+ 3.5mmol/l; glucose 6mm0l/l; chloride 110mm0l/l; bicarbonate = 10mmol/l; urea = 7.0mmol/l

a. 15b. 17c. 22d. 29

30. Regarding water excretion, which is true?

a. At least 87% of filtered water in kidney is reabsorbedb. About 5% of filtered water is removed in the distal tubulec. Aquaporin -1 plays a major role in water conservation, although it is

unaffected by vasopressind. All of the above are correct

31. H+ secretion in the distal nephron is enhanced by all of the following EXCEPT

a. An increase in the level of plasma aldosteroneb. An increase in the tubular lumen concentration of poorly reabsorbable

ionsc. Hyperkalaemiad. Respiratory acidosis

32. Renin release from the juxtaglomerular apparatus is inhibited by which of the following?

a. agonistsb. Prostaglandinsc. Increased pressure within the afferent arteriolesd. Stimulation of the macula densa

33. Which of the following substances will be more concentrated at the end of the proximal tubule than at the beginning of the proximal tubule?

a. Glucoseb. Creatininec. Bicarbonated. Phosphate

34. Ammonia is an effective and important urinary buffer for which of the following reasons?

a. Its production in the kidney decreases during chronic acidosisb. The walls of the renal tubules are impermeable to NH3 c. The walls of the renal tubules are impermeable to NH4

+

d. Its acid-base reaction has a low pKa

35. The following blood picture is most likely consistent with:( Na+ = 120mmol/l, K+ = 6.7 mmol/l, chloride = 95mmol/l, bicarbonate = 20.)

a. Normalityb. 1 adrenal insufficiencyc. 1 hyperaldosteronismd. Diabetes insipidus

36. What is the glomerular filtration rate when urine flow = 1ml/minute; arterial plasma level of inulin = 0.20mg/ml, and urine concentration of inulin is 40mg/ml?

a. 80ml/minb. 150ml/minc. 200ml/mind. 400ml/min

37. Which of the following substances is both reabsorbed +/- secreted in the kidney?a. Potassiumb. Sodiumc. Bicarbonated. Glucose

38. Regarding renal handling of sodium, which is true?

a. Sodium is reabsorbed in the proximal tubule by the Na+ /2Cl-/ K+ transporter.

b. Mineralocorticoids increase tubular reabsorption of sodium.c. Sodium excretion is decreased by drugs that decrease renal acid

secretion by inhibiting carbonic anhydrase.d. Overall = 90% of sodium filtered at the glomerulus is reabsorbed.

39. Regarding water excretion from the kidney, which is true?

a. Aquaporin 2 – is found in the cells of the thin ascending loop of Henle.b. At least 67% of filtered water is absorbed – even when urine volume is

very high.c. The ascedning limb of the loop of Henle is impermeable to water.d. When vasopressin is absent – the collecting duct epithelium is

permeable to water.

40. Which of the following is false with respect to angiotensins?

a. Angiotensin I’s sole action is as a precursor of Angiotensin IIb. Angiotensin II is 4 to 8 times most potent vasoconstrictor than

noradrenalinec. Patients with cirrhosis are less responsive to Angiotensin IId. Angiotensin III has less aldosterone stimulating effect than Angiotensin

II

41. Regarding buffers in body fluids which is false?

a. H2PO4- is a major buffer in the bloodb. bicarbonate is a principal buffer in interstitial fluidc. proteins are important buffers in intracellular fluidd. proteins are one of the major buffers in the blood

  42. Regarding pH of body fluid which is true?

a. gastric acid pH is around 3.0b. pancreatic secretion pH is around 5.0c. plasma pH is normally around 7.0d. urine can sometimes be as acidic as a pH of 4.5

  43. Renal acid secretion is altered by a change in which of the following?

a. partial pressure of CO2b. concentration of serum potassiumc. level of carbonic anhydrased. all of the above

  44. Regarding ammonia secretion which is false?

a glutaminase enzyme helps facillitate ammonia secretionb. glutamic dehydrogenase helps facillitate ammonia secretionc. the amount of ammonium ion excreted is reduces as urine pH increasesd. non-ionic diffusion is process by which the NH4+ concentration gradient is maintained across the tubules

  45. Which of the following is true of the renal secretion of H+?

a. facilitated by renal tubular bicarbonate, ammonia and H2PO4-b. occurs via the sodium, hydrogen antiport in the interstial border of proximal tubule cellsc. all of the aboved. none of the above

  46. What stimulates Vasopressin (ADH) secretion?

a. Increased osmotic pressure of plasmab. Decreased ECF volumec. Angiotensin IId. All of the above

47. What decreases Vasopressin secretion?

a. Alcoholb. Standingc. Carbamezepined. Nausea & vomiting

48. Renin secretion is increased by which of the following?

a. Vasopressin (ADH)b. Angiotensin IIc. catecholaminesd. hypertension

49. Which is true in regards to Angiotensin?

a. Its precursor, Angiotensinogen, is produced by the Adrenals.b. Is inactive in its Angiotensin III form.c. It stimulates both aldosterone & vasopressin released. Is most active as Angiotensin I

50. What is true regarding erythropoietin?

a. 85% comes from the kidneys, the remainder from the liver.b. Has a half life of 5hrs, but its effect takes 2-3 days to appear.c. As plasma haematocrit decreases, the erythropoietin level increases in a linear fashion.d. All of the above

51. Which of the following causes relaxation of mesangial cells in the glomerulus?

a. Endothelinsb. Angiotensin IIc. Noradrenalind. Dopamine

52. Regarding substances used for the measurement of GFR which of the following is false?

a. Must be readily secreted and reabsorbed in the tubulesb. Must not be metabolisedc. Must be non-toxicd. Must be freely filtered in the glomerulus

53. As stimulation of the renal nerves increases which of the following is false?

a. Renin secretion is increasesb. Na+ reabsorption is increasesc. GFR increasesd. Sensitivity of the JG cells increases

54. Where is Na+ reabsorbed in the largest quantities?

a. Proximal tubuleb. Thick ascending loop of Henlec. Distal convoluted tubuled. Collecting ducts

55. In which portion of the nephron does Aldosterone regulate sodium absorption?

a. Proximal tubuleb. Thick ascending loop of Henlec. Distal convoluted tubuled. Collecting ducts

56. Which is true regarding the nephron?a. the glomerular basement membrane allows free passage of all substances less than 4mmb. the nephron is 200um in diameterc. podocytes form filtration slits 25nm wided. glomerular capillary endothelium has pores 200nm in diameter

57. With respect to cellular function in the kidney, which is false?

a. juxtaglomerular cells secrete renninb. I cells secrete prostagladinsc. mesangial cells take up immune complexesd. P cells are involved in ADH-stimulated water reabsorption

58. Which is true regarding renal blood flow?

a. a high protein diet increases renal blood flowb. Angiotensin II and dopamine increases renal blood flowc. protagladins decrease cortical blood flowd. noradrenaline constricts efferent arterioles

59. Which is false with respect to renal blood flow?

a. the medulla is vulnerable to hypoxiab. medullary flow is greater than cortical flowc. cortical PO2 = 50 mmHgd. clearance of PAH = 630 ml/min

60. Which of the following relaxes mesangial cells?

a. Angiotensin IIb. PGF2c. PGE2d. Histamine

61. Which of the following is not secreted by the tubules?

a. creatinineb. uric acidc. potassiumd. sodium

62. What is the renal threshold for glucose in men?

a. 375 mg/minb. 300 mg/dLc. 180 mg/dLd. 300 mg/min

63. Regarding permeability and transport in the nephron, which is false?

a. the thin portion of the loop of Henle is impermeable to Na+b. the thick ascending limb is impermeable to waterc. the tubular fluid is isotonic to plasma at the end of the loop of Henled. most water and Na+ reabsorption occurs in the proximal convoluted tubule

64. Which of the following does not increase Na+ excretion?

a. ANPb. Angiotensin IIc. increased GFRd. PGE2

65. Which is true regarding K+ excretion?

a. rate of excretion is proportionate to rate of flow of tubular fluidb. Most K+ excretion occurs in the proximal tubulesc. it is decreased when Na+ concentration is high in the distal tubuled. it is decreased when H+ secretion is decreased

66. Which is incorrect regarding mechanism of action of some diuretics?

a. Spironolactone – inhibits action of aldosterone in collecting ductsb. amiloride – inhibits ENaCs in collecting ductsc. frusemide – inhibits Na-K-2Cl channels in the thick ascending Loop of Henled. Thiazides – inhibits Na-H exchange in proximal convoluted tubule

67. Regarding body fluid composition, which is true?a. Phosphates are more abundant in plasma than in intracellular fluidb. Cl- is the dominant anion in intracellular fluidc. Proteins tend to have a negative charge at physiologic pHd. Extracellular fluid constitutes 40% if the total body weight

68. Which of the following is true with respect to buffers and fluid/solute movement?a. The buffering capacity of an acid is best when its pKa is higher than the pH of

the solutionb. Fick’s law states diffusion is inversely proportionate to the cross-sectional

areac. Osmolarity if affected by the volume of the various solutes in the solutiond. Because of glucose metabolism, infusion of 5% glucose has the net effect of

infusing a hypertonic solution

69. During replication, which is incorrect?a. During mitosis, separation of the DNA is catalysed by DNA polymeraseb. In RNA, uracil replaces the thymine in DNAc. Transcription is the production of RNA from DNAd. Translation is catalysed by RNA polymerase

70. Which of the following is a nutritionally essential amino acid?a. Arginineb. Alaninec. Glutamined. Tyrosine

71. Which is incorrect regarding plasma lipids?a. Free fatty acids can circulate as lipoproteins bound to albuminb. The endogenous pathway transports lipoproteins from the intestine to the

liverc. Exogenous ingested lipids are transported by chylomicronsd. Lipoprotein lipase requires heparin as a cofactor

72. Regarding buffering systems which is correct? a. Carbonic anhydrase is found in high concentrations in the gastric-acid

secreting cells and the renal tubular cellsb. Haemoglobin acts as a bufferc. In a respiratory acidosis and alkalosis, buffering is almost all intracellulard. All of the above are correct

73. Regarding the Siggaard-Andersen curve nomogram, which is correct? a. The nomogram plots total CO2 concentration against pHb. Higher Hb concentrations cause a loss of buffering abilityc. The buffer base is equal to the total number of buffer anionsd. The Base Excess is positive in acidosis

74. Renal acid secretion is enhanced by which of the following factors? a. High PCO2, Low K+, Aldosterone activityb. High PCO2, High K+, Aldosterone activityc. Low PCO2, Low K+, Aldosterone inhibitiond. High PCO2, Low K+, Aldosterone inhibition

75. Regarding compensatory mechanisms for acid-base disturbance, which is incorrect?

a. HCO3- is reabsorbed in exchange for H+

b. Cations are lost producing diuresis with low acid loadsc. The limiting urinary pH is about 4.5d. Respiratory compensation of a metabolic alkalosis is limited by the

mechanisms of the carotid and aortic chemoreceptors

76. With regard to ammonia secretion, which is false? a. Ammonia is very water soluble so diffuses into urine along its concentration

gradientb. In chronic acidosis, the amount of excreted ammonia decreasesc. The process of ammonia secretion into the urine is called ionic diffusiond. All of the above

77. Which of the following is correct regarding Na+ handling in the kidney:a. 60% is reuptaken in the Collecting ductsb. The Na-K-2Cl cotransporter is present in the thick ascending loopc. Aldosterone mainly affects Na+ transport in the PCTd. The majority of filtered Na+ is not reabsorbed

78. When measuring GFR using Inulin, if Urine flow is 1ml/min, Plasma inulin concentration is 0.25mg/ml and Urine inulin concentration is 30mg/ml, the GFR is:

a. 120ml/minb. 12ml/minc. 7.5ml/mind. 30ml/min

79. Which of the following factors and its effect on renal blood flow is correctly paired?

a. Noradrenaline: Increases RBFb. Acetylcholine: Decreases RBFc. Angiotensin II: Decreases RBFd. Dopamine: Decreases RBF

80. Regarding Glucose handling in the kidney, which is true?a. 50% of filtered glucose is reabsorbedb. Glucose is transported together with Na+

c. There is no threshold for the amount of Glucose that can be absorbed per unit volume

d. The main transport of Glucose occurs in the DCT

81. The effect of salt and water concentration in the Thick ascending Loop on the Renal arteriolar pressure is called:

a. Autoregulationb. Glomerulotubular balancec. Splayd. Tubuloglomerular feedback

82. Principle buffers in the blood include all EXCEPT: a. Sodiumb. Bicarbonatec. Proteind. Haemoglobin

83. Match pH with it’s correct fluid: a. Gastric HCl – pH 5.0b. Pancreatic juice – pH 8.0c. Maximal urine acidity – pH 4.0d. Normal plasma – pH 7.2

84. Which of the following is true with regards to urinary pH changes: a. pH of urine varies from 4.0 to 9.0b. For each H+ ion excreted there is a net gain of 2 HCO3- ionsc. Has implications for the body’s electrolyte and acid-base economy.d. When base is added to the body fluids, the HCO3- ions are buffered

raising the plasma OH-.

85. In respiratory acidosis: a. There is a reduction in arterial PCO2 caused by increased ventilation.b. the interior of cells become less acidic with increased PCO2c. Renal tubular H+ secretion is decreased.d. HCO3- reabsorption is increased.

86. In metabolic acidosis: a. The plasma pH is highb. The plasma HCO3- is lowc. The arterial pCO2 remains highd. The plasma pH, HCO3- and pCO2 are all high

87. Regarding vasopressin, which is false?a. All vasopressin receptors are G-coupledb. It increases expression of aquaporin-1 channels in the collecting ductsc. Haemorrhage is a potent stimulus for secretiond. V1a receptors are also found in the liver and brain

88. Which of the following increases vasopressin secretion?a. Decreased osmotic pressure of plasmab. Increased ECF volumec. Nausea and vomitingd. Alcohol

89. Which of the following does not increase renin secretion?a. Cirrhosisb. Cardiac failurec. Diureticsd. Lying down

90. In the kidney, erythropoietin is secreted by:a. Cells in the peritubular capillary bedb. Cells in the distal tubulesc. Cells in the proximal tubulesd. Cells in the macula densa

91. Dehydration increases plasma concentration of all of the following except?a. Aldosteroneb. Angiotensin IIc. Vasopressind. ANP