Arteries have thick walls rich in elastic fibres because they
- A. carry deoxygenated blood only
- B. must collapse when empty
- C. must withstand and smooth out the high pressure of blood from the heart
- D. need to store lymph between meals
Explanation
Each heartbeat stretches the elastic walls, which then recoil and keep blood moving between beats, converting a pulsatile flow into a steadier one. Veins work at low pressure and so have thinner walls.