RENAL. 6. Renal acid secretion is affected by all of the following except a. pco 2 b. K c. Carbonic anhydrase d. Aldosterone e. Ca

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1 RENAL 1. The reabsorption of Na in the proximal tubules a. Reabsorbs 80% of the filtered sodium load b. Causes increased hypertonicity c. Is powered by N/H ATPase d. Shares a common carrier with glucose e. All of the above 2. In chronic acidosis the major adaptive buffering system in the urine is a. Carbamino compounds b. HCO 3 c. Ammonia d. Histidine residues e. Phosphate 3. These gases ph 7.32, pco 2 31, HCO 3 20mmol/L represent a. Primary metabolic acidosis b. Primary respiratory alkalosis c. A picture consistent with diuretic abuse d. Mixed respiratory acidosis, metabolic acidosis e. Partly compensated metabolic acidosis 4. with regard to osmotic diuresis a. urine flows are much less than in water diuresis b. ADH secretion is almost zero c. The concentration of the urine is less than plasma d. Increased urine flow is due to decreased water resorption in the proximal tubule and loop of Henle e. Osmotic diuresis can only be produced by sugars such as mannitol 5. Which of the following is most permeable to water a. Thin ascending limb of the loop of Henle b. Distal convoluted tubule c. Thin descending limb of the loop of Henle d. Cortical portion of the collecting tubule e. Thick ascending loop of Henle 6. Renal acid secretion is affected by all of the following except a. pco 2 b. K c. Carbonic anhydrase d. Aldosterone e. Ca

2 7. Glucose reabsorption in the kidney is a. A passive process b. Closely regulated with K c. Resembles glucose transport in the intestine d. Occurs predominantly in the distal tubule e. Is the same in all nephrons 8. with regard to urea a. it moves actively out of the proximal tubule b. it plays no part in the establishment of an osmotic gradient in the medullary pyramids c. all of the tubular epithelium is impermeable to urea except for the inner medullary portion of the collecting duct d. a high protein diet reduces the ability of the kidneys to concentrate urine e. ADH has no effect on the movement of urea across tubular epithelium 9. Which of the following best describes the changes in uncompensated respiratory alkalosis a. Low ph, HCO3 and PaCO2 b. High ph, low HCO3 and PaCO2 c. Low ph and HCO3 and normal PaCO2 d. High ph, low HCO3 and normal PaCO2 e. Low ph, high HCO3 and normal PaCO2 10. Which of the following regarding the nephron is true a. The capillary endothelium has 4nm pores b. Filtration slits are approximately 8nm wide c. Filtration slits formed by podocytes are closed by a thin membrane d. Mesangial cells are located between the basal lamina and the podocytes e. Mesangial cells function only as flow refulation 11. regarding the tubules of the nephron which is false a. the DCT has a thick brush border b. the PCT is approximately 15mm long c. the collecting duct epithelium contains intercalated cells d. the longest loops of henle are in juxtamedullary nephrons e. the juxtaglomerular apparatus contains 3 types of cells 12. Which of the following is false regarding the renal circulation a. The lymph drainage is into the superior mesenteric vein b. The descending vasa recta is non-fenestrated c. The pressure drop across the glomerulus is in the order of 1-3mmHg d. The kidneys receive approximately 25% of CO e. Renal blood flow exhibit autoregulation across a perfusion pressure range of approximately mmHg

3 13. Which of the following effects on the renal blood flow is true a. Increased by NA b. Increased by high protein diet c. Increased by angiotensin II d. Decreased by ACh e. Decreased by DA 14. Regarding filtration in the nephron which is false a. Contraction of mesangial cells decreases GFR b. Particles less than approx 4nm are freely filtered c. Angiotensin II and vasopressin causes mesangial cell contraction d. Exchange across the glomerular capillaries is diffusion not flow limited e. Albuminuria in nephritis occurs without an increase in filtration size 15. regarding tubuloglomerular feedback, which is true a. tends to maintain renal blood flow b. the sensor is JG cell c. operates via contraction of the mesangial cells d. acts to reduce GFR if the flow rate in the ascending loop of Henle falls e. GFR is modulated via contraction or dilation of the afferent arteriole 16. regarding water excretion in the kidney, which one is false a. a minimum of 87% of filtered water is reabsorbed b. aquaporin 2 is inserted into the luminal membrane of the collecting duct under the control of vasopressin c. the DCT removes approximately 5% total filtered fluid d. the thin part of the ascending loop of Henle is permeable to water e. the PCT removes 60 70% of te filtered load 17. During an osmotic diuresis, which is true a. The concentration of sodium delivered to the loop of Henle falls b. The sodium concentration in the interstitium of the PCT falls c. Increased fluid load but decreased sodium load to the DCT d. The concentration gradient in the medullary pyramid rises e. Volumes of urine are less in a pure water diuresis 18. calculate the free water clearance based on the following values. Urine flow 200mL/h, plasma osmolality 300mOsm/kg and urine osmolality 450 mosm/kg a. 100 ml/h b. 77 ml/h c. 300mL/h d. -77 ml/h e. -100mL/h

4 19. Regarding H + excretion a. H + is secreted in the PCT via an ATPase b. P cells in the collecting duct actively excrete acid c. The limiting urine ph is approximately 5.5 d. For each H + secreted in the PCT, one Na and one HCO 3 enters the interstitium e. Carbonic anhydrase in the DCT luminal membrane facilitates H + buffering and the formation of H 2 CO Acid secretion is not increased in the following a. Aldosterone b. Hypokalaemia c. Carbonic anhydrase inhibitors d. High arterial pco 2 e. Chronic acidosis 21. regarding Na handling by the kidney, which is false a. aldosterone acts via synthesis of new sodium channels b. ANP produces a diuresis through the inhibition of Na/K ATPase c. Angiotensin II acts to increase Na absorption in the PCT d. PGE 2 causes a natriuresis e. Daily output can range from 1 400mEq/d 22. Regarding the regulation of K excretion, which of the following is true a. The rate of K excretion is inversely proportional to the rate of flow of tubular fluid b. K secretion is increased in conditions of alkalosis c. Hypoaldosteronism produces elevated urinary K levels d. Carbonic anhydrase inhibitors decrease the excretion of K e. Increased Na delivery to the collecting ducts leads to increased K reabsorption 23. regarding the bladder, which is false a. when out carousing and ale drink, once the seal is broken its broken b. there is no somatic innervation to the detrusor muscle c. the reflex contraction of the detrusor usually begins at approximately mL d. long term lesions of the cauda equine produce a dilated thin walled bladder e. micturition is fundamentally spinal cord reflex

5 24. In the kidney a. K is actively reabsorbed in the DCT b. K excretion is decreased when H secretion is decreased c. K does not compete with H in tubular fluid d. The rate of K secretion is proportionate to the rate of flow of tubular fluid in the distal nephron e. K is reabsorbed and Na secreted in DCT 25. In regards to the renal handling of Na a. Na is actively transported out of all parts of the renal tubule b. Na is pumped out of the thin portion of the loop of Henle by Na/K ATPase c. The N/K ATPase extrudes 1 Na in for 1 K out of the tubular cell d. Most of the Na is actively transported out of the tubular cell into the lateral intercellular spaces e. Around 60% of Na is reabsorbed back into the circulation 26. In the kidney a. K secretion in DCT and collecting ducts mainly occur through Na dependent transport mechanism b. ph of 4.5 in the urine is the limiting ph for H secretion c. for each H secreted, 2 Na ions are reabsorbed d. the H secretion in the PCT is mainly dependent on ATP driven proton pump e. the carbonic anhydrase inhibitors increase H secretion 27. In the kidney a. Glucose is secreted by the collecting duct b. The renal threshold refers to glucose resorption from the urine c. Glucose is reabsorbed by 2ndary active transport d. Glucose is reabsorbed in the loop of Henle e. There is no glucose carrier in the kidney 28. In the loop of Henle a. Descending limb is impermeable to water b. Thin ascending limb is permeable to water c. Thick ascending limb is permeable to water d. Fluid in the descending limb becomes hypotonic e. Fluid at the top of the ascending limb is hypotonic cf plasma 29. With respect to filtered water by the nephron a. At the end of the PCT 15% of filtered water is resorbed b. 5% of filtered water is removed by the DCT c. <87% of filtered water is reabsorbed when the urine volume is 23L in 24hours d. 30% of filtered water is removed by the loop of Henle e. total solute excretion over 24 hours depends on the urine volume

6 30. Renal acid secretion is independent of a. K b. Intracellular CO 2 c. Carbonic anhydrase level d. Aldosterone e. ADH 31. With respect to buffers in the blood a. Plasma is rich in carbonic anhydrase b. Oxyhaemoglobin is better buffer than deoxyhaemoglobin c. Phosphate is an important buffer in plasma d. 80% of the acid load in metabolic acidosis is buffered in plasma e. the most effective buffers have pk values close to the ph of the environment they operate in 32. With regards to the regulation of K excretion, K is a. Passively reabsorbed in the DCT b. secretion does no undergo adaptation c. excretion is increased when H ion secretion is increased d. is actively reabsorbed in the PCT e. excretion is independent of Na concentration in the distal tubular fluid 33. Osmotic diuresis a. Increased urine flow is due to decreased water reabsorption in the PCT and loops b. In osmotic diuresis the amount of water reabsorbed in PCT is normal c. Na reabsorption from the proximal tubules is unaffected by osmotic load d. Medullary hypertonicity is increased e. ADH prevents the concentration of urine approaching that of plasma 34. The greatest permeability to urea is found in a. Inner medullary portion of the collecting tubule b. DCT c. Thin descending limb of loop of Henle d. Thick ascending limb of loop of Henle e. Thin ascending limb of loop of Henle 35. With respect to tubular function a. Creatinine resorption is dependent on tubular flow rates b. Creatinine is secreted by the tubules c. Sodium is actively transported out of the thin portion of the loop of Henle d. glucose resorption occurs by passive diffusion mainly in proximal tubules e. urine acidification does not occur in the collecting tubules

7 36. In the kidney a. Glucose is removed from the urine by secondary active transport b. 100% glucose is absorbed in the DCT c. the calculated renal threshold for glucose is lower than its actual value d. phlorizin enhances glucose binding to the sodium glucose symport e. levo isoform of glucose is more efficiently transported by the sodium glucose smport 37. Regarding renal tubular function a. The clearance is less than the GFR if there is tubular secretion b. The active transport of Na occurs in all portion of the tubule c. Proximal tubular reabsorptate is slightly hypotonic d. Water can leak across tight junctions back into the tubule lumen e. 30% of the filtered water enters the DCT 38. Regarding the renal handling of sodium a. 80% of the total filtered sodium load is reabsorbed b. Na is actively transported out of all parts of the renal tubule except for the thin portion of the loop of Henle c. Only a minority of Na is actively transported via the lateral intercellular spaces d. Na transport is coupled to the movement of H and glucose but not to amino acids and phosphates e. The Na/H exchanges in the proximal tubule extrudes one Na for ever H reabsorbed 39. The juxtaglomacular apparatus a. Contains macular densa cells in afferent and efferent arterioles b. Containes juxtamglomerular cells in the afferent arterioles only c. Responds to a fall in arterial pressure by increasing renin secretion d. Responds to an increase in Na concentration by increasing GFR e. Releases renin which is activated by angiotensin I 40. In metabolic alkalosis a. A common cause is the ingestion of aspirin b. Respiratory compensation can fully restore ph to normal c. Base excess is positive d. Treatment with NaHCO 3 restores ph to normal e. There is more renal excretion of H ions 41. Compensatory mechanisms in metabolic acidosis include a. A fall in ph b. Decreased CO 2 formation c. Decreased minute volume d. An alkaline urine e. Reduction in the pco 2 of alveolar gas

8 42. In the normal structure of the kidney a. Mesangial cells can assists in the regulation of glomerular function b. Basal lamina has filtration slits of 25nm c. DCT has a less obvious brush border than the PCT d. The macula densa is located in walls of the afferent arteriole near the termination of the thick ascending loop of Henle e. The collecting ducts commence at the corticomedullary junction 43. Which is false about the loop of Henle a. Descending loop is permeable to water b. Ascending loop is impermeable to water c. Chloride is transported out of the thick part of the ascending limb d. At the top of the ascending loop the tubular fluid is hypotonic e. Tubular fluid is hypertonic as it enters the descending limb 44. Renal blood flow a. Glomerular capillaries drain into peritubular veins b. Renal autoregulation is prevented by denervation c. Oxygen extraction is higher in the cortex than the medulla d. Kidney s receive approximately 15% CO e. Angiotensin II causes greater constriction of the efferent than the afferent arteriole 45. What is the GFR (ml/min) if the urinary concentration of inulin is 40mg/mL, the urinary flow rate is 60mL/h and the plasma concentration is 0.4mg/ml a. 0.6 b. 2.6 c. 100 d. 160 e with respect to how sodium is handled by the kidney a. is actively transported out of all parts of the renal tubule except the thick portion of the loop of Henle b. changes in aldosterone concentration takes ~ 6 hours before an appreciable change to sodium reabsorption is noted c. increasing intracellular Ca concentration inhibits sodium reabsorption d. most of the Na/H exchange by active transport is performed in the DCT e. tubuloglomerular feedback ensures a constant proportion of Na is reabsorbed for any change in the GFR

9 47. Water excretion a. At least 95% is reabsorbed b. 50% of the filtered water is reabsorbed by the end of the PCT c. the first part of the DCT is impermeable to water d. water tends to recirculate in the medullary pyramids e. decreasing the tonicity in the medulla has no effect on water excretion 48. Urinary buffers a. Carbonic anydrase in the DCT increases the buffering capacity b. Dibasic phosphate sytme plays a role in buffering in the distal tubule and the collecting ducts c. The conversion of glutamate to glutamine in the renal tubular cells provide NH 3 for buffering d. The largest ph difference between the tubular cells and the lumen occurs across the PCT e. The NH 4 + content of the urine increases with serum HCO 3 concentrations above 28mmol 49. With respect to the following ABG taken on 24% O 2 ph , po2 135, pco2 28, HCO3 26 a. The person would b expected to have a lower po2 b. The person has an acute metabolic alkalosis c. The person is demonstrating respiratory compensation d. The person has a chronic respiratory alkalosis e. In a few days time they would compensate by lowering HCO3 concentrations 50. The most important buffer in intracellular fluid is a. Bicarbonate b. Ammonia c. Dipphosphate d. Albumin e. Myoglobin 51. In micturition a. Contraction of the trigone is mainly responsible for emptying of the bladder b. The relationship between bladder volume and intravesical pressure has a linear relationship c. The first urge to urinate is produced at 250mL d. Urine in the female urethra empties by contraction of the periurethral smooth muscle e. Sympathetic nerves play no role in micturition

10 52. With regard to tubuloglomerular feedback a. The GFR increases when flow through the distal tubule increases b. The macula densa on the affertent arteriole is the sensor c. The afferent arteriole is constricted by TXA 2 d. It is designed to maintain Na re-absorption e. It does not operate in individual nephrons 53. With respect to the counter current system a. The loops of Henle act as counter current exchangers b. Solute diffuse out of vessels conducting blood towards the cortex c. Water diffuses out of the ascending vessels d. Water diffuses into the collecting ducts e. Counter current exchange is passive and can operate even if counter current multiplication ceases 54. regarding the osmolality of renal tubular fluid it is a. hypotonic in the loop of Henle b. isotonic in the PCT c. hypertonic in the DCT d. hypotonic in the collecting duct e. hypotonic in the PCT 55. renal autoregulation a. the macula densa cells sense change in afferent arteriolar pressure b. falling GFR results in feedback to decrease efferent arteriolar pressure c. falling GFR results in an increase in renin secetion from the macula densa cells d. decreased macula densa concentration of NaCl results in dilation of the afferent arteriole e. decreased GFR decreases NaCl reabsorption in the ascending loop of Henle 56. What is the clearance of a substance when its concentration in plasma is 1mg/mL, its concentration in urine is 10mg/mL and urine flow is 2mL/min a. 2mL/min b. 10mL/min c. 20mL/min d. 200mL/min e. clearance cannot be determined from the information given

11 57. regarding the PCT which is false a. Na is co-transported out with glucose b. Na is actively transported into the intracellular spaces by Na/K ATPase c. The cells are characterized by a brush border and tight junctions d. ADH increases the permeability of water by causing the rapid insertion of water channels into the luminal membrane e. Water moves out passively along osmotic gradients 58. With regard to the effects of hormones on the renal tubules, which is correct a. Aldosterone increases K reabsorption from the distal tubule b. Angiotensin II increases H secretion from the proximal tubule c. ADH increases water reabsorption in the PCT d. ANP decreases Na reabsorption from the PCT e. PTH increases PO4 reabsorption 59. the thin ascending loop of Henle is a. relatively permeable to water b. relatively impermeable to Na c. permeable to both Na and water d. relatively impermeable to water e. relatively impermeable to both Na and water 60. In relation to acid base balance in the body a. Respiratory compensation in metabolic alkalosis is limited by carotid and aortic chemoreceptor response b. HCO 3 concentration will decrease in compensated respiratory acidosis c. The rate of renal H secretion is not affected by pco 2 in respiratory acidosis d. Cl excretion is decreased in respiratory acidosis e. Hepatic glutamine synthesis is decreased in chronic metabolic acidosis 61. Regarding renal compensation in respiratory acidosis and alkalosis a. The rate of HCO3 reabsorption is inversely proportional to the arterial pco2 b. In respiratory acidosis, HCO3 reabsorption is reduced c. Changes in plasma Cl concentration are proportional to HCO3 concentrations d. In respiratory alkalosis, renal H secretion is increased e. HCO3 reabsorption depends upon the rate of H secretion by the renal tubular cells

12 62. All of the following effect GFR except a. Changes in renal blood flow b. Urethral obstruction c. Dehydration d. Oedema outside of the renal capsule e. Glomerular capillary pressure 63. The thick ascending loop of Henle a. Is impermeable to water b. Has maximal permeability to NaCl c. Is relatively permeable to water d. Is impermeable to NaCl e. Is a site where there is no active transport of Na 64. In the normal bladder, micturition is a. Initiated by the pelvic nerves b. Co-ordinated in the lumbar portion of the spinal cord c. Initiated at a volume of 600mL d. Significantly affected by sympathetic nerves e. not facilitated at the level of the brain stem 65. In the kidney Na is mostly absorbed with a. HCO3 b. Glucose c. K d. Ca e. Cl 66. The filtration fraction of the kidney is a. 0.1 b. 0.2 c. 0.3 d. 0.4 e the main buffer in the interstitium is a. protein b. Hb c. Phosphate d. Ammonia e. HCO3

13 68. Regarding the anion gap a. It is the difference between cations including Na and anions including CL and HCO3 b. It is increased in hyperchloraemic acidosis secondary to ingestion of NH4Cl c. It is decreased when Ca/Mg is decreased d. It consists mostly of HPO 4 2-, SO 4 2- and organic acids e. It is decreased when the albumin is increased 69. What factor decreases renin secretion a. Hypovolaemia b. Supine position c. Cardiac failure d. Na depletion 70. With regard to the kidney a. Has optimum autoregulation over a range of mmHg b. Medullary blood flow is greater than cortical blood flow c. PGs decrease medullary blood flow d. PGs increase cortical blood flow 71. The ratio of HCO3 ions to carbonic acid at ph of 7.1 is a. 1 b. 10 c. 0.1 d. 100 e hypokalaemic metabolic acidosis may be associated with a. carbonic anhydrase inhibitors b. diuretic use c. chronic diarrhea 73. All of the following represents an acid load to the body except a. DKA b. CRF c. Fruit d. Ingestion of acid salts 74. What is the osmolality of the interstitium of the tip of the papilla a. 200 b. 800 c d e. 3000

14 75. What is the H ion concentration at a ph of 7.4 a meq/L b meq/L c meq/L d meq/L e meq/L 76. Hypokalaemic metabolic alkalosis is associated with a. Carbonic anhydrase inhibition b. Diuretic use c. Chronic diarrhea 77. Which of the following would be best used for measuring GFR a. Radiolabelled albumin b. Inulin c. Deuterium oxide d. Tritium oxide e. Mannitol 78. given the following values, calculate the GFR: urine PAH 90, plasma PAH 0.3, urine inulin 35, plasma inulin 0.25, urine flow 1mL/min, Hct 40% a. 120 b. 150 c. 180 d. 240 e. 400

15 ANSWERS 1. D 2. C 3. E 4. D 5. C 6. E 7. C 8.?C 9. B 10. C 11. A 12. A 13. B 14. D 15. E 16. D 17. A 18. E 19. D 20. C 21. B 22. B 23. D 24. D 25. D 26. B 27.?C 28. E 29. B 30. E 31. E 32. D 33. A 34. A 35. B 36. A 37. D 38. B 39. C 40. C 41. E 42. A 43. E 44. E 45. C 46. C 47. C 48. B 49. E 50. C 51. E 52. C 53. B 54. B 55. D 56. C 57. D 58. D 59. D 60. A 61. E 62. D 63. A 64. A 65. E 66. B 67. E 68. D 69. B 70.? 71. B 72. A 73. C 74. C 75. B 76. B 77. B 78. B