What is the primary function of the lymphatic system?

The primary function of the lymphatic system is to filter lymph fluid and support immune function. The lymphatic system consists of a network of vessels, lymph nodes, and organs such as the spleen and thymus that work together to maintain fluid balance in the body and facilitate the immune response.

When interstitial fluid accumulates in tissues, it is collected by lymphatic vessels and transported as lymph to the lymph nodes. These nodes are critical for filtering the lymph to remove pathogens, foreign particles, and cellular debris. Immune cells, such as lymphocytes, are produced and activated in the lymph nodes, playing a pivotal role in the body's defense mechanisms against infections.

This distinct role of the lymphatic system underscores its importance in both fluid homeostasis and immune surveillance for maintaining overall health. The other options do not align with the primary roles of the lymphatic system, focusing instead on functions carried out by other systems, such as the circulatory system, endocrine system, or digestive system.