Adrenal Medulla: catecholamines

Question 1

what is catecholamine release associated with

Answer 1

cortisol

Question 2

what catecholamine is mostly in blood

Answer 2

norepinephrine

Question 3

what catecholamine is mostly in the adrenal medulla

Answer 3

epinephrine

Question 4

primary action of dopamine

Answer 4

neurotransmitter - very little in plasma

Question 5

how are catecholamines metabolized

Answer 5

adrenal medulla (recycled), CNS, liver, and kidneys

Question 6

4 stimuli of catecholamine

Answer 6

fight, flight, fear, reproduction

Question 7

how is epi released

Answer 7

sympathetic nerve stimulates adrenal medulla via Ach to release epi to act on distant target cells

Question 8

how is norepi released

Answer 8

sympathetic nerve stimulates Ach at the needed area to release norepi for action on target cells at point of release

Question 9

how is tyrosine made into L dopa

Answer 9

tyrosine hydroxylase with copper cofactor (O2, NADH tetrahydropteridine

Question 10

how is L dopa made into dopamine

Answer 10

L-aromatic AA decarboxylase and pyridoxal phosphate

Question 11

how is dopamine made into norepi

Answer 11

dopamine beta hydroxylase, O2, NADH or NADPH

Question 12

how is norepi made into epi

Answer 12

SAM and phenylethanolamine N methyltransferase

Question 13

what stimulates dopamine formation into norepi

Answer 13

sympathetic activity

Question 14

what stimulates norepi formation into epi

Answer 14

cortisol

Question 15

what inhibits tyrosine formation into L dopa

Answer 15

negative sympathetic feedback and small negative feedback from norepi

Question 16

where is epi made

Answer 16

cytoplasma of chromaffin cells

Question 17

how is catecholamine release acutely regulated

Answer 17

Ach binding to adrenal medulla chromaffin cell triggers Ca cascade which promotes exocytosis of epinephrine from secretory granules

Question 18

how is catecholamine release chronically regulated

Answer 18

stress triggers hypothalamus to release ACTH which releases cortisol. cortisol induces PNMT (enzyme) and SAM to convert norepi to epi. epi is packaged in neurosecretory granules and released

Question 19

what adrenergic receptor dilates pupil

Answer 19

alpha

Question 20

adrenergic receptor activates salivary glands

Answer 20

beta 1

Question 21

adrenergic receptor increases HR and contractility

Answer 21

beta 1

Question 22

adrenergic receptor dilates airways

Answer 22

beta2

Question 23

adrenergic receptor decreases motility

Answer 23

alpha2

Question 24

adrenergic receptor decreases motility

Answer 24

alpha 2 and beta 2

Question 25

adrenergic receptor increases sphincter contraction

Answer 25

alpha 1

Question 26

adrenergic receptor for ejaculation

Answer 26

alpha

Question 27

2nd msgr alpha 1 adrenergic

Answer 27

IP3

Question 28

2nd msg alpha 2 adrenergic

Answer 28

cAMP

Question 29

how do a1 and a2 receptors differ

Answer 29

if a1 is triggered, increase IP3 to increase Ca in the cell to cause smooth muscle contraction and gland cell secretion (cutaneous and GI vasoconstiction, urethral sphincter contraction) if a2 is triggered, cAMP reduces and inhibits the cell

Question 30

inhibitory or excitatory alpha receptros

Answer 30

usually excitatory

Question 31

inhibitory of excitatory beta receptors

Answer 31

inhibitory

Question 32

2nd msgr beta receptors

Answer 32

all act through cAMP through different effects and tissues

Question 33

what if beta1 receptor triggered

Answer 33

cardiac muscle stimulated and increased tissue metabolism

Question 34

beta2 receptor triggered

Answer 34

relaxation of muscle in respiratory passages and in blood vessels of skeletal muscle if camp increase, constriction of gut sphincter if decrease, muscle vessel dilation and detrusor relaxation

Question 35

beta 3 receptor triggered

Answer 35

release of FA by adipose tissue for metabolic use in other tissues

Question 36

what degrades catecholamines

Answer 36

monoamine oxidase and other stuff

Question 37

what is the final metabolic product of catecholamine breakdown?

Answer 37

regardless of degradation pathway, is vanillymandelic acid (VMA)

Question 38

plasma profile epinephrine

Answer 38

increase glucose, increase FFA, not much change of AA

Question 39

how is a2 receptor special

Answer 39

only one that inhibits (decrease cAMP and inhibit cell activity)