Lymphology Association of North America (LANA) Practice Exam

What is the purpose of the bicuspid valves in the lymphatic collectors?

1. To prevent the collector from dilating

2. To increase propulsion

3. To prevent lymphatic leakage

4. To prevent retrograde flow

The correct answer is: To prevent retrograde flow

The purpose of the bicuspid valves in the lymphatic collectors is primarily to prevent retrograde flow. These valves facilitate unidirectional movement of lymph fluid, ensuring it moves toward the lymph nodes and ultimately into the venous system. By preventing backflow, the bicuspid valves maintain efferent flow and prevent any pooling of lymph at various points within the collectors. This is crucial for the efficient drainage of the interstitial fluid and metabolic wastes from tissues, as well as for preserving the homeostasis of lymphatic circulation. While other options may reflect aspects of lymphatic function, they do not encapsulate the primary role of bicuspid valves, which is to ensure that lymph flows in one direction. For instance, while preventing leakage does relate to overall lymphatic function, it is not the specific purpose served by the bicuspid valves. Similarly, although increased propulsion is a critical function of the lymphatic system as a whole, it is not the direct role of the valves themselves. Valves prevent collector dilation indirectly by contributing to efficient flow, but their main responsibility is to block any backward movement of lymph fluid.