Unlike blood vessels, lymph vessels have one-way valves to ensure the lymph moves in only one direction.  True   False

Answer:

True

Explanation:

Lymph vessels, also known as lymphatic vessels, are designed to transport lymph fluid which is a clear fluid derived from interstitial fluid that helps to maintain fluid balance within the body. These vessels contain one-way valves that play a crucial role in ensuring that lymph moves in a single, unidirectional flow toward the lymph nodes and ultimately back to the bloodstream.

This mechanism prevents the backflow of lymph, similar to how veins function in the circulatory system. The valves are essential for the proper functioning of the lymphatic system, especially because lymph does not have a pump like the heart to assist its movement. Instead, lymph is propelled through the vessels by muscle contractions, as well as fluctuations in pressure within the thoracic cavity during breathing. This unique design helps to keep the lymphatic fluid circulating effectively, which is vital for immune function and maintaining tissue homeostasis.