Arteriolar blood pressure, vascular resistance and blood flow

Question 1

When does functional hyperaemia occur? (excess blood in vessels)

Answer 1

• Exercise
• Sweating
• Cardiac muscle
• Chewing (Salivary glands)
• Smooth muscle and glands when digesting

Question 2

What substances are released by the endothelium during vasoconstriction?

Answer 2

PGs and NO

Question 3

How is arteriolar resistance regulated?

Answer 3

• sympathetic noradrenergic nerve fibers supply the arterioles (release noradrenaline)
• increase stimulation of alpha adrenoreceptors on smooth muscle
• increase intracellular calcium
• this causes vasoconstriction

Question 4

What factors determine the level of arteriolar blood pressure?

Answer 4

Cardiac output (CO) and Total Peripheral Resistance (TPR)

Question 5

What happens to the composition of the aorta as you age?

Answer 5

Becomes stiffer (Less recoil from less elastin). This increases SP and decreases DP

Question 6

What happens to SP when the Stroke Volume (SV) increases?

Answer 6

It increases

Question 7

What happens to DP when the TPR increases?

Answer 7

Leads to increase DP