Question

In veins, valves are present to check backward flow of blood flowing at

• A. atmospheric pressure
• B. high pressure
• C. low pressure
• D. all of these.

Answer 1

Answer: (C)

Veins carry blood at low pressure as compared to blood carried by arteries. Arteries carry blood from the heart whose function is to pump blood at high pressure so that blood can reach each and every part of the body. Veins carry blood from tissues to the heart, so they carry blood at low pressure. Valves are present in the veins to prevent backflow of flood due to force of gravity.