Urinary Concentration Mechanisms Flashcards Preview

Human Function- Exam 4 Material > Urinary Concentration Mechanisms > Flashcards

Flashcards in Urinary Concentration Mechanisms Deck (18):
1

how does ADH signaling work?

binds to G protein coupled V2 receptor
G protein activates adenylate cyclase which makes cAMP which activates PKA
PKA phosphorylations result in aquaporin and urea transporter insertion

2

what is the urine concentration excretion requirement?

600mOsmoles/day

3

what is max antiduresis?

0.5 L of 1200mOsmole urine

4

what is max diuresis?

10L of 60 mOsm urine

5

what is the gradient between the tubule and interstitial in the loop of henle?

200 mOsm

6

how does the counter current multiplier system work?

water is removed from thin descending tubule and Na is removed from the thick ascending tubule to make the tubular fluid/interstitial fluid the correct concentration to maintain the 200mOsm concentration gradient
*concentration of thin descending tubule and interstitial match-->thick ascending is 200 more
*concentration of collecting duct matches the concentration of interstitial fluid

7

what are osmotic diuretics?

presence of poorly reabsorbed osmolytes cause tubules to retain water, which increases urine flow (glucose, mannitol, isosorbide)

8

what can osmotic diuretics be used for?

stalled/failing kidneys to increase urine flow

9

what is syndrome of inappropriate ADH release?

high ADH with inappropriate water conservation
results in hypotonic volume expansion

10

what are the symptoms of syndrome of inappropriate ADH release?

hyponatremia
hyposmotic plasma
hyperosmotic urine
increased Na excretion

11

how is inappropriate ADH release treated?

fluid restriction
hypertonic NaCl administration
ADH antagonists

12

what is diabetes insipidus?

lack of ADH control resulting in uncontrolled water loss
hypertonic volume contraction

13

what are symptoms of diabetes insipidus?

polydipsia
polyuria
elevated plasma Na and osmolality

14

what is central diabetes insipidus?

central defect in ADH defect

15

what is nephrogenic diabetes insipidus?

renal defect in responding correctly to ADH

16

how can you distinguish between the two types of diabetes insipidus?

administration of ADH
central DI will respond
nephrogenic will not

17

what is the treatment for central DI?

ADH analog that is more selective for V2 receptors

18

what is the treatment for nephrogenic DI?

nonloop diuretic
decreased salt intake
NSAIDs- inhibit prostaglandin inhibition of ADH and Na reabsorption