Question about lymphatic system.....!!!!?

Question

When comparing the flow of lymph in the lymphatic system with the flow of blood in the circulatory system, it can be said that the lymphatic system also ...

A. uses a pump
B. contains fluid that travels in only one direction
C. uses valves to prevent backward flow
D. contains fluid that travels in a closed circuit

Answer 1

C.
Lymph does not use a pump other than the pumping action of skeletal muscles as they move, nor does it have a closed circuit: lymph vessels are open-ended in tissues. The main lymph vessel in the thorax has valves to prevent the lymph from flowing backwards.