What are veins? What prevents the back flow of blood from veins?

Asked by Topperlearning User | 4th Jun, 2014, 01:23: PM

Expert Answer:

Veins are vessels which carry carbon dioxide-rich blood from all parts of the body back to the heart. There are valves present in veins which allow blood to flow only towards heart and thus prevents the back flow of blood from veins.

Answered by  | 4th Jun, 2014, 03:23: PM