Which organ system is responsible for regulating fluid volume and pressure in body tissues during exercise?

The organ system that plays a crucial role in regulating fluid volume and pressure in body tissues during exercise is the lymphatic system. This system is responsible for maintaining fluid balance in the body by managing the movement of interstitial fluid—fluid found in the spaces between cells. During exercise, physical activity increases blood flow and may cause fluid to accumulate in tissues due to increased permeability of blood vessels. The lymphatic system helps to return excess fluid from the tissues back to the bloodstream, preventing edema and ensuring optimal nutrient exchange and waste removal.

While the nervous system is involved in coordinating responses to exercise, it does not directly manage fluid balance. The endocrine system does play a role in regulating various body functions during exercise, such as hormone release that may influence water retention, but it does not directly regulate fluid volumes in tissues. The muscular system contributes to overall movement and metabolic demands during exercise but does not have a role in fluid regulation. Therefore, the lymphatic system’s essential function in managing interstitial fluid and maintaining proper fluid pressure in tissues makes it the correct answer.