Which system helps maintain fluid balance and contributes to immunity?

The lymphatic system plays a vital role in maintaining fluid balance in the body by transporting excess interstitial fluid back into the bloodstream, preventing edema and ensuring that tissues can retain their proper osmotic balance. Additionally, this system is integral to the immune response. It produces and transports lymph, which is rich in immune cells, such as lymphocytes, that identify and combat pathogens and foreign substances. The lymph nodes, part of the lymphatic system, filter lymph fluid and serve as sites where immune responses can be activated, thus directly contributing to the body’s ability to defend against infections.

The other systems, while important, do not primarily function to maintain fluid balance in conjunction with immune support. The endocrine system regulates hormones that influence various bodily functions, but it does not directly manage fluid balance in the same manner as the lymphatic system. The integumentary system, which includes the skin, protects the body but does not actively participate in fluid balance or immune defense at the level the lymphatic system does. The digestive system primarily focuses on nutrient absorption and waste elimination rather than fluid regulation or immunity. Thus, the lymphatic system is distinctly specialized for these crucial functions.