Question

Which structures in the lymph vessels ensure that lymph flows in one direction? valves lymph nodes ducts lymphocytes

Answer 1

Answer:

Option A,  Valves

Explanation:

Lymphatic vessels are valved structures as they carry thin walled valves in it. Valves allow one way movement of lymph fluid. As the pressure inside a lymphangion increases, the semilunar valve opens and allows the movement of lymph fluid  into another lymphangion. This semilunar valve prevents the backward flow of the lymph fluid and thus a lymphatic system requires no central pump to operate efficiently.

Answer 2

The correct answer are valves. As lymphnodes become larger and deeper they turn into lymph vessels that develop one-way valves. These valves prevent the back flow of blood throughout the vessel and ensure that the lymph only flows in one direction.