Adrenal Physiology Flashcards Preview

Endocrine > Adrenal Physiology > Flashcards

Flashcards in Adrenal Physiology Deck (68):
1

3 layers of adrenal cortex

glomerulosa, fasciculata, reticularis

2

glomerulosa makes ___

aldosterone

3

fasciulata produces ____

glucocorticoids

4

reticularis produces ____

androgens

5

medulla produces _____

adrenaline

6

GFR salt sugar sex

mnemonic for adrenal cortex layers

7

Adrenocorticol hormones are produced where?

p450 in mitochondria and smooth ER of adrenal gland

8

Rate limiting step in steroidgenesis is ____

scc enzyme cleavage of cholesterol to pregnenolone by CYP11A1

9

Corticosterone is converted to aldosterone by

aldosterone synthase --> glomerulosa cells only

10

Aldosterone is released in response to (3) ____

increased: angiotensin 2, serum potassium, and ACTH

11

Cortisol is released in response to (2) ____

increased: ACTH and arginine vasopressin

12

Androgens are released in response to ____

increased ACTH

13

Norepi and epinephrine are released in response to _____ and its synthesis is dependent on high local concentrations of _____

sympathetic nervous system activation and cortisol

14

Aldosterone binds to ____ receptor to regulate ___ (2)

mineralocorticoid: blood volume and salt/water homeostasis

15

Cortisol binds to ____ receptor to regulate ____ (2)

glucocorticoid receptor: energy balance, cv, metabolic, immune homeostasis

16

Androgens bind ____ receptor and regulate ___

androgen: pubarche

17

norepi/epi bind ___ receptors to regulate ___ (2)

adrenergic: cv and bronchial dilation

18

______ senses blood volume, salt concentration in kidney

juxtaglomeruler cells

19

Renin is released in response to _____ (2)

decreased afferent arteriole volume (low renal perfusion) and decreased distal tubule sodium concentration (tubuloglomerular feedback)

20

Renin is decreased in response to ____ (2)

increased afferent arteriole volumea nd increased distal tubule sodium concentration

21

Potassium and angiotensin II sstimulate _____ in the zona glomerulosa

aldosterone synthetase

22

Renin

converts angiotensin to angiotensin I

23

ACE

converts angiotensin I to angiotensin II

24

Effect of aldosterone

increased Na reabsorption/water absorption, K+ and H+ secretion --> increase blood volume, decrease blood potassium concentration

25

Increased circulating K induce production of aldosterone which promotes Na reabsorption in exchange for K in the _______ of the nephron

distal tubule and collecting duct

26

- feedback for renin system

increase in BP turns off renin production and reduces production of vasoconstrictor angiotensin ii

27

T/F angiotensin ii induces production of aldosterone via direct effect on adrenal gland.

T

28

T/F cortisol has negative feedback on both ACTH and CRH

T

29

Stimulants of ACTH

CRH, vasopressin, inflammation

30

ACTH specific receptor is _______ on _____

melanocortin 2 receptor on adrenal tissue

31

ACTH receptor functions

increase LDL receptors to bring in more cholesterol for steroid hormones, activate CYP11A1 for cholersterol scc

32

T/F ACTH can function as melanocortin

T --> conserved sequence which allows it to activate melanocortin 1 receptor on melanocytes --> high ACTH can stimulate pigment production

33

T/F cortisol rapidly declines after awakening

T

34

At what time of day do we measure cortisol in order to determine adrenal insufficiency

7-8am

35

At what time of day do we measure cortisol in order to determine adrenal overactivity

midnight

36

Cortisol effect on: liver

gluconeogenesis, decrease glucose uptake

37

Cortisol effect on: skeletal muscle

release AA, insulin resistance (Blocks glucose uptake)

38

Cortisol effect on: immune

decrease macrophage, T cell, mast cell activity (antihistamine)

39

Cortisol effect on: bone

increase osteoclast, decrease calcium absorption --> osteoporosis

40

Cortisol effect on: adipose

release ffa and glycerol

41

Cortisol effect on: heart

increase bp via vasoconstriction, increase adrenergic receptor responsiveness

42

Cortisol effect on: vascular smooth muscle

vasomotor tone, responsiveness to vasoconstrictors

43

Cortisol effect on: adrenal medulla

epinephrine synthesis (PNMT activation)

44

T/F mineralocorticoid receptor has more affinity for cortisol than aldosterone

T

45

11beta HSD2

converts cortisol to cortisone (shunt) for mineralocorticoid rich tissue --> ensures aldosterone can have an effect in tissues like kidney

46

11betahsd1

reverses 11betahsd2 in tissues like liver to ensure cortisol has more impact

47

licorice moa

inhibits 11betahsd2 --> lots of cortisol --> hypertension, hypokalemia (psuedohyperalodsteronism)

48

adrenal androgens (3)

dhea, dheas, androstenedione

49

T/F increase in adrenal androgens with age

T

50

T/F andrenarche begins years before gonadarche

T

51

In peripheral tissues, androstendione is converted to ____ (2)

testosterone and estrone

52

main site of androgen production in women

adrenals

53

main site of androgen production in men

testes (adrenals are minor)

54

Adrenal medulla receives input form SNS through preganglionic fibers from _____ spinal cord

thoracic

55

T/F medulla lacks synapses from postganglionic fibers

T --> releases secretions directly into blood

56

Rate limiting step in catecholamine synthesis

tyrosine --> dopa via tyrosine hydroxylase

57

T/F cortisol promotes epinephrine synthesis

T --> upregulates PNMT for production of epinephrine from norepinephrine

58

epi/norepi production ratio in adrenal medulla

80/20

59

Metanephrines

not nuclear receptors--> surface membrane receptors

60

T/F catecholamines and metanephrines have a short half life in blood

T --> signal through second messenger systems --> not nuclear receptors

61

Location: alpha 1 adrenoceptor

arterial/venous vasculature: increase IP3 (vasoconstriction, increased bp)

62

Location: alpha 2 adrenoceptor

arterial/venous vasculature and nerve terminals: decrease cAMP

63

Location: beta 1 adrenoceptor

heart, juxtaglomerular apparatus: increase cAMP

64

Location: beta 2 adrenoceptor

heart, skeletal muscle vasculature, bronchial smooth muscle: increase cAMP --> bronchodilation, vasodilation)

65

__________ the principal mineralocorticoid, is produced in the ______ and released in response to ____ and ____ and acts on the collecting tubule to increase sodium reabsorption in exchange for _____ and ___ ion, therby restoring _____ and lowering serum ____ concentrations

Aldosterone, zona glomerulosa, hyperkalemia and angiotensin II/ACTH, +/H+, intravascular volume, and lowering serum potassium

66

______, the principal glucorticoid is produced in the _______ and is released in response to ____, acting to maintain serum ____ concentration, maintain vascular _____, and to attenuate ______

cortisol, fasciularis/reticulata, ACTH, serum glucose, vascular resistance, inflammatory/immune/wound repair response

67

____ (3) , the principal androgens from the adrenals are produced in ____ and released in response to ____ and ____ is converted in peripheral tissues to ____ and ____, sex hormones.

DHEA,DHEAS, and androstenedione, zona reticulata, ACTH, androstenedione to testoerone and estrone

68

_____ (2) are the principal catecholamines and produced in the ______ and released in response to ____ stimuli to produce _____ and _____. ___ also increases ___ production by stimulating PNMT.

norepi/epi in the medulla, SNS stimuli to produce bronchial dilation and vascular resistance, cortisol increases epinephrine production