Regulation of Arteriole resistance

Question 1

Arteriole radius and what can be said to linked

Answer 1

mean arterial pressure

Question 2

To keep the blood flow to each vascular bed sufficient, and keep mean arterial pressure in the right range, you have to engage in some resistance juggling.

How is this achieved

Answer 2

by 2 levels of control over the smooth muscle surrounding the arterioles

Question 3

what are intrinsic mechanisms concerned with

Answer 3

meeting the selfish needs of each muscle tissue

Question 4

what are extrinsic mechanisms concerned with

Answer 4

ensuring that total peripheral resistance of the whole body stays at the right level

Question 5

describe extrinsic control by sympathetic nerves

Answer 5

Sympathetic nerves
release norepinephrine
binds to a1-receptors
causes arteriolar constriction

Question 6

describe extrinsic control by parasympathetic nerves

Answer 6

usually no effect

Question 7

describe extrinsic control by hormones

Answer 7

Epinephrine
released from adrenal medulla
binds to a1-receptors
causes arteriolar constriction

Question 8

what other receptor can epinephrine activate in skeletal and cardiac muscle which in turn results in arteriole dilation

Answer 8

B2 receptors, therefore this will increase flow but decrease TPR

Question 9

what is Angiotensin II produced in response to

Answer 9

low blood volume

Question 10

what is the effect of Angiotensin II

Answer 10

causes arteriolar constriction

Question 11

what type of hormone is vasopressin

Answer 11

an antidiuretic hormone

Question 12

what is vasopressin produced in response to

Answer 12

low blood volume

Question 13

what is the effect of vasopressin

Answer 13

causes arteriolar constriction

Question 14

what are Atrial natriuretic peptide & Brain natriuretic peptide released in response to

Answer 14

in response to high blood volume

Question 15

what are the effects of Atrial natriuretic peptide & Brain natriuretic peptide

Answer 15

cause arteriolar dilation

Question 16

what is active (metabolic) hyperaemia

Answer 16

Active hyperemia is the increase in organ blood flow (hyperemia) that is associated with increased metabolic activity of an organ or tissue.

Question 17

what is reactive hyperaemia

Answer 17

Reactive hyperemia is the transient increase in organ blood flow that occurs following a brief period of ischemia (e.g., arterial occlusion).

Question 18

the coronary circulation shows what type of hyperaemia

Answer 18

active

Question 19

in pulmonary circulation what happens to arterioles when O2 decreases and why

Answer 19

arteriolar constriction, this ensures that blood is directed to the best ventilated part of the lungs

Question 20

there are “special areas” in relation to regulation of arteriolar resistance. These areas have specific properties that correlate with their function, what are these areas

Answer 20

cerebral circulation
renal circulation
pulmonary circulation
coronary circulation

Question 21

what does epinephrine bind to

Answer 21

a1 receptors

Question 22

what is the effect of epinephrine

Answer 22

causes arteriolar constriction