S10 arterial blood flow Flashcards Preview

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

Epinephrine

A

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
Q

Serotonin (5-hydroxytryptamine)

A

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
Q

Histamine

A

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
Q

Arginine Vasopressin (AVP)

A

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

5
Q

Endothelins (ETs)

A

source: endothelial cells

receptors and function: ETa receptors on VSCMs, causing vasoconstriction

6
Q

Bradykinin (BK)

A

source: kininogens in plasma

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

7
Q

Aterial Natriuretic peptide (ANP)

A

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
Q

prostaglandins

A

source: many tissues synthesize these derivatives of arachidonic acid

9
Q

Nitric oxid (NO)

A

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

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

10
Q

Non vasoactive substances

A

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

11
Q

non Vasoactive substances signal kidney thru four effector pathways

A

reinin-ANG2- aldosterone axis

autonomic nervous system

posterior pituitary that res

atrial myocytes that release ANP

12
Q

ANP and Brain Natriuretic peptide (BNP)

A

systemic vasodilation

arterial hypotension

reduced venous pressure

reduced pulmonary capillary wedge pressure