4.5 Overview of anatomy of arteries and veins

Question 1

What are the three layers of blood vessels and what are they made of?

Answer 1

Tunica externa - collagen and elastic fibres
Tunica media - smooth muscle
Tunica interna - endothelium and basement membrane

Question 2

how is blood flow modulated in vessels?

Answer 2

The smooth muscle of the tunica media contracts or relaxes to alter the diameter of the lumen

Question 3

What is the role of the pre capillary sphincters?

Answer 3

restricts flow to the meta-arteriole when there is sufficient blood but will open up and allow blood into the capillary bed when the tissue is suffering

Question 4

What are the three mechanisms of venous return?

Answer 4

vein constriction
skeletal muscle pump
respiratory pump

Question 5

how does the muscle pump work?

Answer 5

muscle contraction forces the blood flow through the vein and the valves ensure only one way flow

Question 6

where do the intercostal arteries branch off?

Answer 6

aorta but 1 and 2 from subclavian