Physiology and Pharmacology: Circulation + anatomy of blood vessels

Question 1

3 structural layers of blood vessels?

- proportions in each different category of vessel?

Answer 1

• Connective tissue adventitia
• smooth muscle layer
• endothelium

Aorta -> large arteries, more elastic tissue to respond to stretching via heart beat

Arterioles -> Less elastic tissue much more smooth muscle (major site of resistance to flow)

Capillaries made from endothelial cells (1 thick)

Veins and venules - walls only slightly thicker that capillaries, relatively little smooth muscle

Question 2

Purpose of valves in veins?

Answer 2

Prevent backflow of de-oxygenated blood (ensures unidirectional flow)