What is the main purpose of the lymphatic system?

The main purpose of the lymphatic system is multifaceted, playing crucial roles in both fluid balance and immune function. It helps to balance fluids in the body by collecting excess fluid that leaks into tissues from the blood and returning it to the bloodstream, thus preventing the accumulation of fluid known as edema. This fluid balancing is vital for maintaining homeostasis, ensuring that tissues receive the proper amount of fluid and nutrients while waste products are efficiently removed.

Additionally, the lymphatic system is integral to the immune response. It produces and transports lymph, a fluid that contains immune cells such as lymphocytes, which are essential for fighting infections. The lymph nodes, distributed throughout the lymphatic system, act as filtration points where immune cells can detect and respond to pathogens, thereby helping to protect the body from infections.

Given its dual functions of fluid regulation and immune support, the most comprehensive answer is that the lymphatic system's main purpose encompasses both balancing fluids in the body and assisting in infection defense.