332e Cellular and Molecular Biology of the Kidney

Question 1

Renal blood flow normally drains approximately what percentage of cardiac output?

Answer 1

20% (1000mL/min)

p. 332e-2

Question 2

Primary driving force for glomerular filtration

Answer 2

Hydrostatic pressure gradient

p.332e-2

Question 3

First line of defense against fluctuations in renal blood flow

Answer 3

Myogenic reflex

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Question 4

Tubuloglomerular feedback (TGF) changes the rate of filtration and tubular flow by reflex vasoconstriction or dilatation of what arteriole

Answer 4

AFFERENT arteriole

p. 332e-2

Question 5

Enzyme that catalyzes the conversion of angiotensin to angiotensin I

Answer 5

Renin

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Synthesized and secreted by granular cells in the wall of afferent arteriole

Question 6

Enzyme that catalyzes conversion of angiotensin I to angiotensin II

Answer 6

Angiotensin-converting enzyme (ACE)

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Question 7

Effect of angiotensin II

Answer 7

Vasoconstriction of EFFERENT arteriole

p. 332e-3

Promotes renal sodium and water reabsorption

Question 8

What does the proximal tubules reabsorb?

Answer 8

~60% of filtered NaCl and water
~90% of filtered bicarbonate
glucose and amino acids

p. 332e-6

Question 9

Carbonic anhydrase inhibitor that blocks proximal tubule reabsorption of bicarbonate and useful in alkalinizing the urine

Answer 9

Acetazolamide

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Question 10

Plasma levels of glucose causing glycosuria

Answer 10

180-200mg/dL

Due to a saturable cellular transport of glucose mediated by apical Na+-glucose cotransport

332e-8

Question 11

Gitelman syndrome is a disorder involving the distal tubule and collecting duct affecting what transporter

Answer 11

Sodium chloride cotransporter

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Question 12

Segment of loop of Henle that is highly water permeable due to active aquaporin-1 channels

Answer 12

Descending thin limb

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Question 13

A process occurring at the loop of Henle responsible for the urinary concentration by contributing to the generation of hypertonic medullary interstitium

Answer 13

Countercurrent multiplication

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Question 14

Salt-wasting disorder associated with hypokalemic alkalosis and hypocalciuria

Answer 14

Gitelman syndrome
SLC12A3 gene mutation

p. 332e-8

Question 15

Cell type of the collecting duct that are the main water, Na-reabsorbing and K-secreting cells, and site of action of aldosterone, K-sparing diuretics

Answer 15

Principal cells

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Type A intercalated cells : acid secretion and bicarbonate reabsorption

Type B intercalated cells : bicarbonate secretion and acid reabsorption