What is the main function of the lymphatic system?

The primary function of the lymphatic system revolves around two critical roles: supporting the immune system and facilitating the return of excess interstitial fluid to the bloodstream. The lymphatic system comprises lymph nodes, lymphatic vessels, and lymphoid organs, which work collectively to filter and transport lymph—a fluid containing infection-fighting white blood cells, as well as other substances.

In terms of immune support, the lymphatic system plays a vital role in detecting and responding to pathogens. Lymph nodes act as immune checkpoints, where lymph is filtered, and pathogens are identified and attacked by lymphocytes. This surveillance system is essential for maintaining the body's defense against infections and diseases.

Furthermore, the lymphatic system ensures that excess fluid, which can accumulate in tissues due to capillary leakage or other factors, is returned to the circulatory system. This not only helps maintain fluid homeostasis within the body but also prevents edema (swelling) which can occur when excess fluid builds up in the tissues.

The other options reflect functions that are associated with different systems in the body. The respiratory system is primarily responsible for oxygen supply to the blood, the digestive system handles nutrient absorption, and the liver and kidney systems are primarily involved in detoxification processes. Thus, the role of the