Question

How are substances exchanged between blood in the capillaries and the cells of the body.

Compare the structure and function of arteries, veins and capillaries.

Answer 1

Substances are exchange between blood inthe capillaries and body cells through diffusion. The substances exchanged are mainly oxygen , carbon dioxide, nutrients.

Arteries :-

1. Carry blood away from heart , oxygeneted ( except pulmonary artery)
2. Thick walled , muscular , elastic
3. Narrow lumen
4. High pressure

Capillaries :-

1. Carry blood away from heart, oxygeneted blood
2. Thin walled
3. Very narrow diameter, no elasticity
4. Low pressure

Veins :-

1. Carry blood towards the heart , deoxygenated (except pulmonary vein)
2. Ella thinner than artery, little elasticity
3. Wide lumen
4. Low pressure