Blood vessels

Question 1

What is the structure of an artery?

Answer 1

Thick muscular wall to carry blood at high pressures
Elastic layers for dilation
Narrow rigid lumen to maintain pressure

Question 2

What is the function of an arteriole?

Answer 2

Also known as resistance vessel.

Controls flow to tissue through influence of local factors and ANS.

Question 3

Describe the structure of a capillary.

Answer 3

A single layer of endothelium for maximum exchange.
Carry blood at low pressures of 35mmHg.
Have no elastin so do not dilate or constrict.

Question 4

Why do venules lack muscle in their walls?

Answer 4

To allow expansion for large volumes

Question 5

Describe the structure of a vein.

Answer 5

Also known as capacitance vessels due to thin walls that alter the amount of volume to be held. Wide lumen for low pressured blood.

Question 6

What is the purpose of a reservoir in the capacitance vessels?

Answer 6

Alters VR.