Catecholamines (cont) and Adrenergic receptors

Question 1

The flight or flight response is mediated by

Answer 1

Norepinephrine
produce and released by neurons

Question 2

No fight or flight response if we see the

Answer 2

HPA Axis
because it needs time (but fight or flight response is a quick response)

Question 3

The fight or flight response is not a response to cortisol

Answer 3

it is a response to stress
- cortisol stimulates EP synthesis and release and works to improve response

Question 4

Norepinephrine functions primarily as a neurotransmitter for

Answer 4

cardiac effects

Question 5

Both norepinephrine and epinephrine influence the

Answer 5

vascular tone
(vasoconstriction and dilation)

Question 6

epinephrine affects

Answer 6

metabolic processes such as carbohydrate metabolism

Question 7

stress hormone (happen quick)

Answer 7

• heart rate increases
• blood sugar levels increase
• blood pressure in arteries increase
• pupils dilate
• intestinal muscles relax
• breathing rate increase
• blood flow to skeletal muscles increase

Question 8

Actions of catecholamine

Answer 8

Norepinephrine
- increase heart rate and blood pressure and peripheral vasoconstriction

Epinephrine
- increase heart rate, blood pressure, peripheral vasoconstriction, increase lipid breakdown, coronary dilation, bronchial dilation, glycogen to glucose

Question 9

catecholamines are initiated through interaction with two different types of specific cell membrane receptors

Answer 9

alpha-adrenergic
- alpha 1
- alpha 2

Beta- adrenergic
- beta 1
- beta 2
- beta 3

Question 10

these receptors have different affinities for norepinephrine and epinephrine and can cause opposing physiological effects depending on …

Answer 10

location and concentration of the hormone

Question 11

at low plasma concentration, EP predominantly stimulates

Answer 11

beta- adrenergic receptors (causing vasodilation)

Question 12

at higher plasma concentration, EP stimulates

Answer 12

alpha receptors sufficiently to override vasodilation and cause vasoconstriction

Question 13

alpha 1

Answer 13

more affinity to NE
Gq&raquo_space;PKC&raquo_space; increase IP3, DAG, and Ca2+ (related to vasoconstriction)

Question 14

alpha 2

Answer 14

more affinity to NE
Gi&raquo_space; Adenylyl cyclase is inhibited = decrease cAMP

Question 15

beta 1

Answer 15

equal affinity to EP and NE
Gs&raquo_space; Adenylyl cyclase&raquo_space; increase cAMP

Question 16

beta 2

Answer 16

more affinity to EP
Gs&raquo_space; Adenylyl cyclase&raquo_space; increase cAMP

Question 16

beta 3

Answer 16

more affinity to NE
Gs&raquo_space; Adenylyl cyclase&raquo_space; increase cAMP

Question 17

effects of circulating epinephrine

Answer 17

• increased heart rate & inotropy (beta1) *depending on concentration alpha1
• vasoconstriction in most systemic arteries and veins (alpha 1)
• vasodilation in muscle and liver vasculatures at low concentrations (B2)
• vasoconstriction at high concentration (alpha1)
• cardiovascular response to low -to moderate circulating concentration of epinephrine includes increase cardiac output and redistribution of the cardiac output to muscular and liver circulations with only a small change in mean arterial pressure (not altered by levels of EP circulating)
• although cardiac output is increase, arterial pressure does not change because the systemic vascular resistance falls due to beta2 activations
• at high plasma concentration, EP increase arterial pressure b/c ninf to alpha 1 on blood vessels which offset B2

Question 18

although EPI and NE can bind to alpha and beta receptors, these are 2 main things that dictate the response

Answer 18

1. affinity for the receptor
2. concentration of the hormone in circulation
3. location of the receptors