3.1.2c) The structure and functions of arteries, arterioles, capillaries, venules & veins

Question 1

Arteries

Answer 1

Carries blood from the heart to the body
Thick, muscular walls & have elastic tissue
Elastic tissue - stretch & recoil to help maintain high pressure
Folded endothelium - allows for the artery to expand - maintain high pressure

Question 2

Arterioles

Answer 2

Have a layer of smooth muscle but have less elastic tissue
Smooth muscle - helps to control amount of blood flowing to tissues

Question 3

Capillaries

Answer 3

Where substances are exchanged
1 cell thick - efficient diffusion of substances

Question 4

Venules

Answer 4

Very thin walls that can contain some muscle cells

Question 5

Veins

Answer 5

Takes blood back to the heart under low pressure, very little elastic & muscle
Valves - prevents backflow
Blood flow helped by contraction of body muscles surrounding them