S10 arterial blood flow

Question 1

Epinephrine

Answer 1

source: adrenal medulla

receptors and functions:

• a1 receptors on VSMC causing Vasoconstriction
• B2 receptors on VSMC causing Vasodilation
• B1 receptors in heart increasing the heart rate and contracility

Question 2

Serotonin (5-hydroxytryptamine)

Answer 2

source:
- serotonergic nerves
- enterochromaffin cells
- adrenal chromatin cells
- platelets and mast cells

Receptors and functions:

• 5-HT2A or 5-HT2b receptors on VSMCs causing vasoconstriction
• particular important with vessel damage (hemostasis)

Question 3

Histamine

Answer 3

source:

• nerve terminals
• mast cells
• enterochromaffin cells

Receptors:
- H2 receptors on VSMCs, causing Vasodilation

Functions:

• histamine causes vascular smooth muscle to relax
• causes visceral smooth muscle (e.g., bronchial smooth muscle in asthma to contract)

Question 4

Arginine Vasopressin (AVP)

Answer 4

hemorrhagic shock causes enhanced AVP release and a vasoconstriction that contributes to a transient restoration of arterial pressure.

Question 5

Endothelins (ETs)

Answer 5

source: endothelial cells

receptors and function: ETa receptors on VSCMs, causing vasoconstriction

Question 6

Bradykinin (BK)

Answer 6

source: kininogens in plasma

receptors and functions: B2 receptors on endoethelial cells, causing release of NO and prostaglandins causing vasodilation.

Question 7

Aterial Natriuretic peptide (ANP)

Answer 7

Source: Atrial myocytes in response to stretch

Receptor: ANP receptor A (NPR1) on VSMCs, causing vasodilation

function: lowers blood pressure
- it has a powerful diuretic and natriuretic actio. it ultimately reduces pslasma contolvolume and there fore blood pressure .

Question 8

prostaglandins

Answer 8

source: many tissues synthesize these derivatives of arachidonic acid

Question 9

Nitric oxid (NO)

Answer 9

Source; Nitric oxide synthase (NOS) produces NO from argninin in endothelial cells

receptors: NO activates the soluble guanylyl cyclase in VSMCs, chains vasodilation.

Question 10

Non vasoactive substances

Answer 10

senses of effective circulating volume send signals to kidney to change the rate of Na_ excretion in the urine (NA+ homeostasis)

Question 11

non Vasoactive substances signal kidney thru four effector pathways

Answer 11

reinin-ANG2- aldosterone axis

autonomic nervous system

posterior pituitary that res

atrial myocytes that release ANP

Question 12

ANP and Brain Natriuretic peptide (BNP)

Answer 12

systemic vasodilation

arterial hypotension

reduced venous pressure

reduced pulmonary capillary wedge pressure