Question

State any five differences between artery, veins and capillaries.

Answer 1

Arteries:
Away from heart
Mainly carry oxygenated blood
High pressure
No valves 
Thick outer wall (pumps a lot more blood)
Thick inner layer of muscle and elastic fibres
Narrow central tube-small lumen(where the blood flows through)

Capillaries:
Wall only one cell thick-really thin -diffusion 
smallest blood vessel

Veins:
Blood into heart
Most carries de-oxygenated blood
Lower pressure 
Valves 
Thin outer walls
Thin inner layer 
Wide central tube -large lumen