Vasc 3

Question 1

Organ blood flow is determined by?

Answer 1

perfusion pressure and vascular resistance

Question 2

Local (intrinsic) control mechanisms for vascular resistance include:

Answer 2

metabolic control
local hormone signals
myogenic factors

Question 3

Metabolic control

Answer 3

Important in matching metabolic needs (blood flow) in working muscle and other critical tissues
Works by means of chemical changes in tissue related to metabolism (occur in absence of BP change)

Question 4

Metabolism related signaling molecules include

Answer 4

CO- dilates
O2-constricts
K-D
Adenosine-D
Lactic acid-D

Question 5

Metabolic control mechanisms also account for ?

Answer 5

blood flow autoregulation

• most prominent in critical tissues
• fails at very high/low perfusion pressures

Question 6

Myogenic factors

Answer 6

stretch receptors in the VSM sense and respond to distending pressure by producing contraction

• arterioles typically show the greatest myogenic contractions compared to larger arteries or the venous system
• skeletal muscle arterioles&raquo_space;> mesenteric artieroles

Question 7

What affects do the following local hormones have :
endothelin-1
NO
Thromboxane
Prostacyclin
Histamine
Bradykinin

Answer 7

endothelin-1
-endothelium, VSM (constricts)
NO
-endothelium, VSM(dilates)
Thromboxane
-endothelium,VSM (constricts)
-platelets,VSM (constricts)
Prostacyclin
-endothelium, VSM dilates
Histamine
-mast cell, VSM(dilates)
Bradykinin
-globulins (blood), VSM(dilates)
-globulins (tissue), VSM(dilates)

Question 8

Cholinergic neurons

Answer 8

synthesize and release ACh
include all pre-ganglionic efferent neurons of both PNS and SNS
post ganglionic of PNS

Question 9

Adrenergic neurons

Answer 9

synthesize NE and Epi(adrenal medulla)
includes post-ganglionic neurons of SNS
adrenal medulla

Question 10

Alpha adrenergic receptors

Answer 10

• Found on VSM membranes of arterioles of all organs and most veins; are innervated by sympathetics
• Activation- vasoconstriction and decreased blood flow in most organs
• increased vasoconstriction in several major organs (increase TPR and increase in systemic BP)

Question 11

Beta-2 adrenergic receptors

Answer 11

found on the coronary arterioles and skeletal muscle arterioles
-not innervated by sympathetics rely on circulating EPI and NE

Question 12

M3 cholinergic receptors are found on?

Answer 12

Arteries and arterioles of most organs

Question 13

Which 3 tissues contain M3 receptors of vascular endothelial cells that are innervated

Answer 13

Coronary arteries/artierioles (PSNS)
External genital organs (PSNS)
Skeletal muscle has M3 innervated by SNS cholinergic nerves to release NO

Question 14

Arterial BP is monitored by?

Answer 14

Baroreceptors

Volume receptors

Question 15

Baroreceptors

Answer 15

Specialized nerve endings found mainly in the walls of the carotid arteries and aortic arch