Arteries, veins and capillaries are the components of the transport system in human beings.
1. Arteries: Arteries are the vessels which carry blood away from the heart to various organs of the body.
2. Veins: Veins collect the blood from different organs and bring it back to the heart under high pressure.
3. Capillaries: These are smallest vessels which have one cell thick. Exchange of material between the blood and surrounding cells takes place across this thin wall.