Renal 6 - sodium Flashcards Preview

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Flashcards in Renal 6 - sodium Deck (76)
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1
Q

what kind of hormone is ADH

A

peptide

2
Q

what is the role of osmoreceptors

A

sense increase in plasma osmolarity

3
Q

where are osmoreceptors

A

in the hypothalamus

4
Q

where is ADH made

A

cell of the supra-optic nucleus in the hypothalamus

5
Q

where is ADH secreted

A

posterior pituitary

6
Q

where is the site of ADH action

A

collecting duct cells

work on specific aquaporins

7
Q

what is the mechanism of action of ADH

A

alters water permeability of the luminal membrane of cortical collecting ducts (increases reabsorption)

8
Q

what are aquaporins

A

water channels found in renal tubule cells (and other cells)

9
Q

which aquaporins in the proximal convoluted tubules

A

AQP1

10
Q

which aquaporins in the collecting ducts

A

AQP 2 3 4

11
Q

what aquaporin does ADH regulate and how and where

A

AQP2
increase gene transcription
luminal side of collecting duct
(physiological regulation)

12
Q

are AQPs on the basolateral membranes regulated by ADH

A

no

13
Q

what happens to AQP2 when there is no vasopressin

A

the channels are reabsorbed into vesicles

less water reabsorption

14
Q

what happens to permeability of water without ADH to the cortical collecting ducts

A

nearly impermeable to water

15
Q

what is water diuresis

A

lots of fluid loss through urine

16
Q

what causes water diuresis

A

absence of ADD

17
Q

what can cause an increase in ADH (environment)

A

warm, shock, pain, no water

18
Q

what can cause an decrease in ADH (environment)

A

cold, humid, alcohol

19
Q

what does high ADH cause

A

retain water

20
Q

what does low ADH cause

A

lose water

21
Q

what is central diabetes insipidus

A

failure to release ADH from posterior pituitary

22
Q

what is nephrogenic diabetes insipidus

A

defect at level of nephron tubule cells,

weak collecting duct cells

23
Q

does diabetes insipidus involve sugar?

A

nah fam, has to do with ADH or ADH RECEPTORS

24
Q

where does most of the gradient come from

A

50% from NaCl

25
Q

how does the interstitial space change in dry environments

A

more of a gradient

26
Q

how does the interstitial space change in non dry environments

A

less of a gradient

27
Q

what is water diuresis

A

when excess water is excreted without excess solute in urine

28
Q

what condition is associated with water diuresis

A

diabetes insipidus

29
Q

what causes diabetes insupidus

A

messed up vasopressin/ADH

30
Q

what is osmotic diuresis

A

excess solute in urine that is associated with high levels of water excretion

31
Q

what condition is associated with omsotic diuresis

A

diabetes mellitus

32
Q

what are short term handlings of low Na in plasma

A

baroreceptors regulate CFR, they become desensitized

33
Q

what are long term handlings of low Na in plasma

A

aldosterone promotes Na reabsorption

34
Q

what does atrial natriuretic peptide do

A

regulates GFR and inhibits Na+ reabsorption

inhibits aldosterone actions

35
Q

how does the body adapt to high Na in plasma

A

releases atrial natriuretic peptide (regulate GFR, inhibit Na reabsorption, inhibit aldosterone).

36
Q

what are baroreceptors

A

nerve endings that are sensitive to stretch, change in blood volume & peripheral resistance

37
Q

where are baroreceptors located

A

carotic sinus, aortic arch, major veind, intrarenal (JG cells of JGA)**

38
Q

do baroreceptors directly or indirectly detect sodium

A

indirectly by sensing water volume

39
Q

what do baroreceptors dectect

A

change in blood volume, BP and stretch

40
Q

what does activation of baroreceptors cause (5 things)

A

increased nerve impulse frequency and activation of the ANS

increate afferent arteriolar constriction, decrease GFR, increase Na reabsorption

41
Q

what kind of hormone is aldosterone

A

steroid

42
Q

where is aldosterone secreted from

A

adrenal cortex

43
Q

what triggers the synthesis and release of aldosterone

A

low sodium

44
Q

is the effect of aldosterone short or long term

A

long term

45
Q

where is the site of action of aldosterone

A

late distal and cortical collecting duct

46
Q

what are the 3 actions of aldosterone

A

induces synthesis of Na transport proteins

stimulates Na reabsorption reduces Na excretion

47
Q

what is Na+ reabsorption linked to

A

K secretion

48
Q

what regulates aldosterone secretion

A

low total body [Na+]

49
Q

what does angiotension 2 do and where

A

acts on adrenal cortex to control secretion of aldosterone

50
Q

where is renin secreted from

A

the juxtaglomerular cells of the JGA in the kidney

51
Q

what do the baroreceptors of the JGA sense

A

low NaCl

52
Q

what secretes angiotensinogen

A

the liver

53
Q

what does ACE do

A

angiotension 1 to 2

54
Q

what does angiotension 2 do

A

cause vasoconstriction and raises blood pressure

55
Q

where does angiotension 2 cause

A

aldosterone release from the adrenal cortex

56
Q

what secretes renin

A

juxtaglomerular cells on the wall of afferent arterioles

57
Q

what kind of cells are juxtaglomerular/ what do they sense

A

mechanoreceptors that sense circulating plasma volume

58
Q

where are macula densa

A

wall of distal convoluted tubule

59
Q

what kind of cells are macula densa/ what do they sense

A

chemoreceptors that sense NaCl

60
Q

is renin involved in tubular glomerular effect

A

no, it only reacts to low Na+

61
Q

which three things determine [renin] in plasma

A

JG cells receive three inputs:

  • sympathetic input from external baroreceptors,
  • intrarenal baroreceptors(afferent arteriole),
  • signals from macula densa*
62
Q

what does decreased stretch do to renin release

A

stimulates renin release

63
Q

what does increased stretch do to renin release

A

inhibits renin release

64
Q

which 3 things are the most important triggers for aldosterone response

A
  • sympathetic stimulation of renal nerves
  • decreased filtrate osmolarity
  • decreased BP
65
Q

where is artial natriuretic peptide made

A

cardiac atria

66
Q

where does artial natriuretic peptide act

A

cells of several tubular segments

67
Q

what does artial natriuretic peptide cause (3 things)

A

inhibit aldosterone
inhibit Na+ rabsorption
increases GFR and Na+ excretion

68
Q

what stimulates atrial natriuretic peptide secretion (3 things)

A

increased Na+ concentration
increase blood volume
atrial distension*

69
Q

where is most of the filtered K+ reabsorbed

A

proximal tubule and loop of henle

70
Q

where can some K+ be secreted

A

collecting duct

71
Q

where is [K+] in urine regulated

A

cortical collecting duct

72
Q

what is hyperkalemia

A

excess K+ in blood

73
Q

what happens with an increase in extracellular K+

A

stimulate aldosterone production, more K+ in urine

74
Q

what happens with an decrease in extracellular K+

A

no aldosterone produced, less K+ in urine

75
Q

what does aldosterone do to K and Na and where

A

stimulates Na reabsorption and K secretion in the cortical collecting duct

76
Q

what does water reabsorption depend on

A

Na reabsorption