ANS and the HEART

Question 1

B1 adrenergic receptor of the heart functions (4)

Answer 1

1. helps HCN channels open
2. helps t type Ca channels open
3. helps L type Ca channels open
4. hastens calcium uptake to get ready for next conduction

Question 2

what nt binds the B1 receptor and what branch of the ANS is it from?

Answer 2

NE…from sympathetic

Question 3

2 effects of NE binding the B1 receptor?

Answer 3

increase conduction velocity of Aps and increase heart rate

positive chronotropic and dromotropic effects

Question 4

chrontotropic effect definition

Answer 4

change in heart rate..if increase it is positive

Question 5

dromotropic effect definition

Answer 5

change in conduction velocity of APs…if faster is positive

Question 6

ACh binding a muscarinic channel in the heart causes what channel to open?

Answer 6

the potassium channel…hyperpolarizing the cells

Question 7

ACh has what effect on heart cells?

Answer 7

slows conduction velocity and decreased heart rate

negative dromotropic and chronotropic

Question 8

when there is a loss of blood volume, what happens to the baroreceptors in the carotid sinus and aortic arch?

Answer 8

they decrease their firing, which is noted by brainstem and ANS is activated

Question 9

two main roles of the B1 adrenergic receptor for arterial pressure

Answer 9

automaticity and myocardial contractility changes

increases heart rate

Question 10

if you give a drug that is an agonist of the B1 adrenergic receptor, what is the effect on the heart?

Answer 10

leads to increased cAMP that then increases Ca release and increases contraction force…so more stroke volume and higher CO

Question 11

which of epi and NE does not have affinity for the B2 receptor but does have it for the B1?

Answer 11

Nor Epi

Question 12

what is A1 adrenergic receptors main role and how does it do it?

Answer 12

increase smooth muscle contraction…by allowing more Ca to be released in the cell leading to more contraction

Question 13

if you give an antagonist of ACh what is the effect on the heart?

Answer 13

it will increase the heart rate since ACh normall slows it…

Question 14

what is the target of an agonist or antagonist of ACh and the para?

Answer 14

M receptors

Question 15

list the 6 receptors of the ANS

Answer 15

a1,a2,b1,b2,M2,M3

Question 16

main Parasympathetic receptor of heart

Answer 16

M2

Question 17

Main sympathetic receptor of heart

Answer 17

B1

Question 18

two drugs that are M2 antagonists and what is their effect on the heart?

Answer 18

atropine and glycopyrrolate

increase the heart rate

Question 19

B1 agonist drug and its effect on the heart

Answer 19

Dobutamine and increase heart rate

Question 20

D1 antagonist drugs (2) and effect on the heart

Answer 20

Metprolol, atenolol and decrease heart rate

Question 21

what are the two receptors that regulate the vessel constriction?

Answer 21

a1 and b2…but more so A1

Question 22

name the A1 antagonist and its function

Answer 22

prazosin…decreases the smooth muscle contraction…vasodilation…decrease BP

Question 23

Name the A1 agonist and its function

Answer 23

midodrine and phenlyephrine

they increase constriction of vessel muscle and increase BP

Question 24

post synaptic role of a2 receptor

Answer 24

smooth muscle contraction

Question 25

pre synaptic role of a2 receptor

Answer 25

negative feedback from NE that leads to decreased calcium so decreased NE release

Question 26

name an A2 agonist drug and give its function

Answer 26

clonidine...actually gives anti sympathetic effect because of the negative feedback

Question 27

what can clonidine treat?

Answer 27

hypertension

Question 28

where do indirect agonists of ach act?

Answer 28

AChesterase

Question 29

propanolol effectors

Answer 29

B1 B2 and B3

Question 30

carvedilol effectors

Answer 30

a1, b1 ,b2, b3