blood vessels

Question 1

arteries

Answer 1

Carry oxygenated blood away from the heart. thick muscular walls. Have small passageways (internal lumen for blood (internal lumen). Contains blood under high pressure.

Question 2

veins

Answer 2

Carry deoxygenated blood to the heart. thin walls.

Have larger passageways for blood. Contain blood under low pressure. Have valves to prevent blood flowing backwards.

Question 3

capillaries

Answer 3

Found in the muscles and lungs. Microscopic – one cell thick. v low blood pressure. Where gas exchange takes place - oxygen passes through the capillary wall and into the tissues, while carbon dioxide passes from the tissues into the blood.