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Flashcards in adrenal Deck (74):
1

what type of neurons innervate the adrenal glands?

sympathetic postganglionic neurons

2

will the adrenal medulla regenerate?

no

3

will the adrenal cortex regenerate?

yes

4

where is the zona arcuata (aka glomerulosa) located?

superficial adrenal cortex

5

where is the zona fasciculata + reticularis located?

deep in the adrenal cortex

6

where is the site of mineralocorticoid synthesis?

zona arcuata

7

where is the site of glucocorticoid and sex hormone synthesis?

zona fasciculata + reticularis

8

is the zona arcuata responsive to ACTH?

no

9

is the zona fasciculata + reticularis responsive to ACTH?

yes

10

loss of ACTH does what to the adrenal cortex?

produces a thin adrenal cortex

11

T/F: the thickness of the zona glomerulosa is affected by loss of ACTH.

false

12

what is the non-specific response to injury or stress by the adrenal glad?

general adaption syndrome

13

adrenocortical hormones are derivatives of what?

cholesterol

14

what are the two sources of cholesterol?

-synthesis in the adrenal cortex
-plasma LDL cholesterol
-(liver)

15

in the steroid nucleus of adrenocortical hormones, how many carbons are there?

C-21s

16

what enzyme does trilostane block?

3,b-dehydrogenase

17

the synthetic pathway of adrenocortical hormone involves what 2 organelles?

-smooth endoplasmic reticulum
-mitochondria

18

do mineralocorticoids have a C17 hydroxyl group?

no

19

do glucocorticoids have a C17 hydroxyl group?

yes

20

where are binding proteins synthesized

the liver

21

what does total glucocorticoid in blood depend on?

-secretion rate
-metabolism
-amount of carrier protein

22

how do steroid travel in aqueous solution (blood)?

binding protein carry the steroid

23

what are steroid binding proteins?

-transcortin for cortisol
-albumin
-free hormone (no protein)

24

what is the reltaionshipt of [cortisol] to [aldosterone]?

[cortisol] is more than 10 fold higher than [adosterone]

25

what is the clearance of cortisol?

60 min half life

26

what is the clearance of aldosterone

20 min half life

27

what causes the differences in the half lives of cortisol and aldosterone?

the carrier protein

28

how/where are steroid hormones metabolized?

-reduction in the liver
-hormones rendered water soluble
-excreted in urine

29

what is the importance of mineralcorticoids?

they are acutely critical for maintaining life

30

what is the most important mineralcorticoid?

aldosterone

31

what does aldosterone protect against?

-hypotension
-hyopnatremia
-potassium intoxication

32

to prevent overstimulation of aldosterone receptor by cortisol, ______ converts ______ to inactive _____.

-11-b hydroxysteroid dehydrogenase
-cortisol
-cortisone

33

can cortisone bind to the mineralcorticoid receptor?

no

34

licorice can inhibit what?
leading to what?

-11-b hydroxysteroid dehydrogenase
-mineralcorticoid excess syndrome

35

what are the physiological actions of aldosterone?

-increases na+ reabsorption from urine, saliva and gastric juices
-increases angiontensin II production
-decreases K+ by increasing renal excretion
-conservation of water follows the conservation of na+

36

what behavior does aldosterone cause together with angiontensin II?

drives salt seeking behavior

37

what regulates aldosterone?

-plasma K+ will stimulate aldosterone by a DIRECT EFFECT ON adrenal zona glomerulosa
-angiotensin II
-poorly regulated ACTH
suppressed by atrial natriuretic factor
-high plasma Na+ and K+ deficiency decrease aldosterone secretion

38

aldosterone and angiotensin II act upon what?

distal tubule and collecting duct

39

what happens when aldosterone and angiotensin II are acting on the kidney?

-resorption of renal sodium and water
-excretion of potassium

40

where is renal renin released?

from the juxtaglomerular apparatus (JG)

41

do aldosterone and angiotensin II synergize?

yes

42

the JG complex acts as what?

a baroreceptor

43

what is the most important glucocorticoid in most species?

cortisol

44

what is the most important glucocorticoid in rabbits, mice and rats?

corticosterone

45

what is the main physiological effect of cortisol?

to stimulate gluconeogenesis -> amino acids to glucose, glycogen to glucose

46

cortisol acts on ____ to release ____.

-liver
-gluconeogenic enzymes

47

what are the 7 effects of cortisol?

1. stimulate gluconeogenesis
2. stimulate protein and fat catabolism
3. redistribution of body fat
4. water and electrolyte distribution
5. trace mineral distribution
6. blocks inflammatory responses
7. suppresses immune system

48

what is the most clinically important effect of cortisol?

that it blocks inflammatory responses

49

how is cortisol regulated?

by negative feedback

50

what is the most important hormone of the pars intermedia?

alpha-MSH

51

what is the most potent glucocorticoid?

cortisol

52

what are three ways you can test adrenocortical function?

1. plasma [cortisol]
2. ACTH response test
3. dexamethasone suppression test

53

what are 4 clinical uses of glucocorticoid?

1. inhibition of inflammatory response
2. immunosuppressant
3. palliative therapy for arthritis, arthrosis
4. replacement therapy for hypoadrenocorticism

54

what animals are most prone to hypoadrenocorticism?

older, female, small breed dogs

55

what is the common term for hyperadrenocorticism?

Cushing's-like syndrome

56

what causes cushing's disease?

secondary to pituitary release of excess ACTH
-pituitary dependent

57

what causes cushing's syndrome?

primary hyperadrenocorticism due to adrenal tumor
-adrenal dependent

58

what is cushings sydrome?

-excessive glucocorticoid synthesis
-secondary to excessive ACTH

59

what is the common name for hyperaldosteronism?

conn's syndrome

60

primary conn's syndrome is caused by what?

adrenal tumor
(adenoma)

61

secondary conn's syndrome is caused by what?

renovascular disease leading to ang II increase

62

what is PPID in horses?

-equine cushing's
- pituitary pars intermedia dysfunction

63

what is a key sign of hypoadrenocorticism?

- bradycardia/widened QRS complex

64

what causes hypoadrenocorticism?

deficiency of mineralocorticoids (aldosterone)

65

cells of the adrenal medulla are innervated by what type of nerve fibers?

pre-ganglionic sympathetic nerve fibers

66

cells of the adrenal medulla are modified by what type of nerve fibers?

post-ganglionic nerve fibers

67

what are the primary hormones synthesized by the adrenal medulla?

epinephrine and norepinephrine

68

what is the key precursor for catecholamine synthesis?

tyrosine

69

tyrosine is inhibited by what?

NE and EPI

70

the actions of catecholamines are mediated by?

alpha- and beta-adrenergic receptors

71

the actions of catecholamines by alpha-receptors are?

-vasoconstriction by NE
-liver glycogenolysis

72

the actions of catecholamines by beta-receptors are?

-increased heart rate/contractility
-bronchodilator
-adipose tissue lipolysis
-vasodilation by epinephrine

73

sympathetic tone is regulated by what?

baroreceptors

74

what is pheochromocytoma?

-means dusky tumor
-neoplasm (often adenoma) in adrenal medulla
-can release catecholamines