S10 arterial blood flow Flashcards Preview

Cardiovascular organ system > S10 arterial blood flow > Flashcards

Flashcards in S10 arterial blood flow Deck (12):
1

Epinephrine

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

2

Serotonin (5-hydroxytryptamine)

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)

3

Histamine

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)

4

Arginine Vasopressin (AVP)

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

5

Endothelins (ETs)

source: endothelial cells

receptors and function: ETa receptors on VSCMs, causing vasoconstriction

6

Bradykinin (BK)

source: kininogens in plasma

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

7

Aterial Natriuretic peptide (ANP)

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 .

8

prostaglandins

source: many tissues synthesize these derivatives of arachidonic acid

9

Nitric oxid (NO)

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

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

10

Non vasoactive substances

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

11

non Vasoactive substances signal kidney thru four effector pathways

reinin-ANG2- aldosterone axis

autonomic nervous system

posterior pituitary that res

atrial myocytes that release ANP

12

ANP and Brain Natriuretic peptide (BNP)

systemic vasodilation

arterial hypotension

reduced venous pressure

reduced pulmonary capillary wedge pressure