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Flashcards in Endocrine: Adrenal Deck (80)
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1
Q

Arterial blood supply to kidneys?

A

superior, middle, inferior suprarenal

2
Q

Which vein returns blood from kidney?

A

suprerenal v.

3
Q

The sinusoid system of blood flow in the kidney allows what to be modulated?

A

enzymatic activity in medulla

4
Q

Which zone of adrenal gland?

aldosterone synth

A

zona glomerulosa

5
Q

Which zone of adrenal gland?

cortisol synth

A

zona fasciculata

6
Q

Which zone of adrenal gland?

DHEA synth

A

zona reticularis

7
Q

Which zone of adrenal gland?

catecholamine synth

A

medulla

8
Q

The order of zonate structures in the adrenal from superficial to deep…

A

ZG
ZF
ZR

9
Q

Synthesis of these two hormones is under pituitary ACTH control…

A

Cortisol and androgens

10
Q

Synthesis of this hormone is under pituitary ACTH and RAAS control

A

aldo

11
Q

Synthesis of medullae are under control of…

A

SNS

12
Q

What is the basis of steroid synthesis throughout the layers of the adrenal gland?

A

absence or presence of enzymes

13
Q

1st step of steroid hormone biosynthesis… catalyzed by…

A

cholesterol to pregnenolone

via cholesterol desmolase

14
Q

What is the rate limiting step of steroid hormone synthesis?

A

cholesterol to pregnenolone

15
Q

Cholesterol desmolase is dependent on the action of which protein, and what hormone?

A

StaR transport to inner mito

ACTH stimulation

16
Q

Thee methods of cholesterol liberation…

A

LDL

hydrolysis of cholesterol esters

de novo by ACoA

17
Q

Progression from cholesterol to aldosterone…

A

Cholesterol

to

pregnenolone

to

progesterone

to

11-deoxycorticosterone

to

corticosterone

to

aldosterone

18
Q

Enzyme for…

pregnenolone to progesterone

A

3B-HSD

19
Q

Enzyme for…

progesterone to 11-deoxycorticosterone

A

21B-Hydroxylase

20
Q

Enzyme for…

11-deoxycorticosterone to corticosterone

A

11B-Hydroxylase

21
Q

Enzyme for…

Corticosterone to aldosterone

A

aldosterone synthase (+ ATII)

22
Q

The zona glomerulosa lacks which enzyme, ensuring pregnenolone can only be converted to progesterone…

A

17-a-hydroxylase

23
Q

What substances stimulate aldosterone secretion, and rank them in order…

A

ANG II > Increase K > ACTH

24
Q

Aldosterone binds to ______ which can then bind to ______ to stimulate sodium reabsorption, potasium/H+ secretion

A

binds to MR1

MR1 binds to MRE

25
Q

A patient presents with…


Increased Na reabsorption: hypernatremia, fluid retention and
hypertension

Increased K + secretion: hypokalemia

Increased H secretion: metabolic alkalosis

Low renin levels
A

Conn’s syndrome

26
Q

Deficiency in 17-a-hydroxylase leads to…

A

increased 11-deoxycorticosterone and corticosterone

no androgens, GC

27
Q

Why is aldosterone level low in 17-a-hydroxylase deficiency?

A

corticosterone excess leads to HTN

28
Q

Three signs of 17-a-hydroxylase deficiency…

A

HTN, hypokalemia, metabolic alkalosis

29
Q

The Z. fasciculata converts cholesterol to…

A

cortisol and corticosterone

30
Q

Which enzyme?

pregnenolone to 17-hydroxypregnenolone

A

17-a-hydroxylase

31
Q

which enzyme?

progesterone to 17-hydroxyprogesterone

A

17-a-hydroxylase

32
Q

which enzyme?

17-hydroxypregnenolone to
17-hydroxyprogesterone

A

3B-HSD

33
Q

Z. Reticularis has which enzymes? (4)

A

Cholesterol desmolase

3B-HSD (vertical)

17-a-hydroxylase (horizontal)

17,20-lyase (horizontal )

34
Q

Z. Fasciculata has which enzymes? (5)

A

Cholesterol desmolase

17-a-hydroxylase (horizontal)

3B-HSD (vertical)

21B-hydroxylase (vertical)

11B-hydroxylase (Vertical)

35
Q

which 2 enzymes does Z. Fasciculata lack? meaning what can’t be produced?

A

aldo. synthase: no aldo

17,20-lyase: no androgens

36
Q

In cortisol synthesis, 17-hydroxypregnenolone is converted to…

A

17-hydroxyprogesterone (3B-HSD)

37
Q

In cortisol synth, 17-hydroxyprogesterone is converted to…

A

11-deoxycortisol (21B-hydroxylase)

38
Q

in cortisol synth, 11-deoxycortisol is converted to…

A

cortisol (11B-hydroxylase)

39
Q

Rows of Enzymes in Adrenal Hormone Synthesis (5 rows)

A

Row 1: desmolase

Row 2: 3B-HSD

Row 3: 21B-hydroxylase

Row 4: 11B-hydroxylase

Row 5: aldo synthase

40
Q

Columns of Enzymes in adrenal hormone synthesis (2 columns)

A

Column 1: 17-a-hydroxylase

Column 2: 17,20-lyase

41
Q

In androgen synthesis, cholesterol is converted to…

A

dehydroepiandrosterone (DHEA)

androstenedione

42
Q

In androgen synthesis, 17-hydroxypregnenolone is converted to…

A

DHEA (17,20-lyase)

43
Q

in androgen synthesis, 17-hydroxyprogesterone is converted

A

androstendione (17,20-lyase)

44
Q

Cortisol has what effect on CRH?

A

direct inhibition

inhibits CRH on corticotrophs

45
Q

ACTH release is…

A

circadian and pulsitile

46
Q

CORT secretion occurs ____ and drops ____

A

high in morning, drops throughout day

47
Q

In times of stress, ACTH secretion is enhanced by…

A

increased amplitude, not frequency

48
Q

Describe the actions of cortisol on glucose…

A

decreased glucose utilization in fat and liver

decreased insulin sensitivity

49
Q

Cortisol has what effect on protein catabolism and lipolysis?

A

increased

50
Q

Cortisol effect on bone…

A

inhibit bone formation

51
Q

anti-inflammatory/immune effects of cortisol

A

inhibits IL-2

inhibits lipocortin, decreased PGs and LTs

52
Q

In the CV system, cortisol up-regulates what receptor?

A

alpha-1

53
Q

In addition to the GR receptor, cortisol can bind ___ because it is closely related to aldosterone…

A

MR receptor

54
Q

11B-HSD Type II has what effect on cortisol?

A

cortisol to cortisone: inactivation

55
Q

What are three factors that enhance specificity of MR to aldosterone instead of cortisol?

A

cortisol binding to albumin, CBG

11B-HSD Type II

Slow aldo dissociation from MR

56
Q

11B-HSD Type I does what?

A

cortisone to cortisol: activation

57
Q

Where is 11B-HSD Type I expressed? What effect does this have on insulin?

A

adipose tissue, can lead to insulin resistance

58
Q

Which condition?

Decreased cortisol, aldo, androgens

hyperpigmentation on elbows, knees, nipples, scars

A

Addison’s, Primary adrenocortical insufficiency

59
Q

What three are compounds are responsible for the skin pigmentation in addison’s?

A

y-MSH, a-MSH, B-MSH via increased POMC/ACTH

60
Q

Which condition:

low ACTH
normal aldo
no hyperpigmentation

A

secondary/tertiary adrenal cortical insufficiency

61
Q

Cushing syndrome is caused by _____ while disease is caused by _____

A

syndrome: adrenal hyperplasia

Disease: excess ACTH

62
Q

Cushings, ACTH is ___ while cortisol is___

A

low ACTH, high cortisol

63
Q

Which condition?

masculinization: penis-like clitoris, scrotum-like labia

sodium loss, hypoglycemia

no GC or MC

A

21B-hydroxylase deficiency

64
Q

Why are ACTH levels high in 21B-hydroxylase deficiency?

A

no cortisol neg feedback on ACTH

65
Q

Synthesis of catecholamines occurs in what cell type?

A

chromaffin cells of medulla

66
Q

What is the pathway of compounds for catecholamine synth?

A

tyrosine

to

DOPA

to

DA

to

NE

to

Epi

67
Q

Which step of catecholamine synthesis occurs in granules?

A

DA to NE

68
Q

Epi is produced in cytosol and stored…

A

in granules

69
Q

Rate limiting step of catecholamine synthesis?

A

Tyr to DOPA (via tyrosine hydroxylase)

70
Q

Enzyme for DOPA to DA

A

amino acid decarboxylase

71
Q

enzyme for DA to NE

A

dopamine-B-hydroxylase

72
Q

Enzyme for NE to Epi

A

phyneylethanolamine-N-methyltransferase

73
Q

Acute stimulation has what effect on tyrosine hydroxylase?

A

increased activity

74
Q

chronic stimulation of tyrosine hydroxylase has what effect…

A

increased expression and concentration

75
Q

What role does cortisol play in catecholamine synthesis?

A

activates phenylethanolamine-N-methyltransferase

76
Q

What degrades NE? where?

A

MAO, neuronal cytopalsm

77
Q

What degrades Epi?

A

COMT, heart/liver/kidney

78
Q

MAO and COMT convert catecholamines to…

A

MHPG

79
Q

MHPG is converted to ____ which can be excreted in the urine.

A

VMA

80
Q

____ is an index of SNS activity/pathology

A

VMA