Blood Flow Regulation - Intrinsic Mechanisms

Question 1

What happens in exercise

Answer 1

CO increases

Proportional blood flow to heart and muscle/skin increases

Dec to others

Brain stays same

Question 2

How does body regulate flow

Answer 2

Changes diameter

Question 3

Acute blood lfow control

Answer 3

Rapid changes in local vasodilation/vasoconstriction of the arterioles, metarterioles, and precap sphincters…occurring within seconds to minutes

Question 4

Intrinsic mechs

Answer 4

Active hyperemia
Reactive hyperemia
Autoregulation
Flow-dep vasodilation

Question 5

Active hyperemia

Answer 5

When metabolic actiivty is increased, blood flow increases

Question 6

Things that lead to smooht muscle relaxation in active hyperemia

Answer 6

Dec O2 
Inc CO2
H+
Adenosine (breakdown of ATP)
K+ (from repeated hyperpolarization)
Eicosanoids (mmb PL product)
Osmolarity 
Bradykinin
NO

Question 7

Reactive hyperemia

Answer 7

Response of tissue blood flow following brief period of local ischemia

Will take longer and have less max in AS dz

Question 8

Autoregulation

Answer 8

Allows blood flow to remina constant in face of changes in perfusion pressure

(sitting to standing)

Question 9

What happens in posture change

Answer 9

IN brain - dec pressure triggers smooth muscle relaxation and dilation

In leg - inc pressure tirggers smooth muscle contraction and contrsitciton

Question 10

Myogenic mech

Answer 10

Vascular smooth muscle contracts in response to inc in pressure stretch and relaxes in response to dec in transmural pressure

Question 11

MEtabolic theroy

Answer 11

Accumulation of metabolites leads to smooht muscle relaxtion and artery dilation

Question 12

Mechs of BF auto reg

Answer 12

Myogenic - More pressure…more stretch…more vasoconstrciton…dec diameter

Metabolic - more pressure…more flow…dec metabolite conc….inc arteriole diameter

Question 13

Flow dependent vasdodilation

Answer 13

Vessel dilates in response ot inc flow

Endothelium dependent