fong VII

Question 1

what contributes to the osmotic gradient?

Answer 1

NaCl and urea

Question 2

what causes the generation of medullary interstitial hypertonicity ?

Answer 2

active NaCl absorption by TALH ( role of urea recycling)

Question 3

what causes the generation of medullarry interstitial hypertonicity?

Answer 3

differential NaCl and H2O permeabilities of all segments of henle’s loop

Question 4

what is absorbed in the medullary collecting duct?

Answer 4

• REGULATED permeability to both Na+ and water

- urea is reabsorbed

Question 5

what keeps the gradient intact?

Answer 5

countercurrent exchange

Question 6

what does feeling does ADH stimulate?

Answer 6

thirst

Question 7

ADH release is impaired in what disease?

Answer 7

CENTRAL DI

Question 8

CENTRAL DI characteristics

Answer 8

• ADH signaling is impaired

- defect is at the SOURCE

Question 9

NEPHROGENIC DI characteristics

Answer 9

• ADH signaling is impaired

- defect is the TARGET

Question 10

in an ADH response test, which form of DI should the administration of ADH increase water absorption?

Answer 10

CENTRAL CI

Question 11

Na+ absorption by CD principle cells is enhanced by what?

Answer 11

aldosterone

Question 12

what does atrial natriuretic peptide inhibit?

Answer 12

Na+ absorption in the CD and it also inhibits angiotensin II (leading to vascular relaxation) and aldosterone production by the adrenal gland