Which system is a complex network providing protection and fluid balance in the body?

The lymphatic system is essential for maintaining fluid balance and providing protection in the body. It is responsible for transporting lymph, a fluid containing infection-fighting white blood cells, throughout the body. This system plays a crucial role in immune function by filtering pathogens and foreign substances through lymph nodes, where immune cells can identify and respond to potential threats.

In addition to its role in immunity, the lymphatic system helps regulate the body's fluid levels by collecting excess interstitial fluid from tissues and returning it to the bloodstream. This ensures that the body's tissues remain properly hydrated and that fluid balance is maintained. The interconnection of lymphatic vessels forms a complex network that is integral to both protecting the body from disease and managing fluid levels within the body's tissue environments.

Other systems listed do not specifically provide this dual function of protection and fluid regulation in the same direct manner as the lymphatic system. For example, the circulatory system is primarily responsible for the transport of blood, nutrients, and gases throughout the body, while the nervous system coordinates voluntary and involuntary responses. The respiratory system focuses on gas exchange, supplying oxygen and removing carbon dioxide, which does not encompass the roles of fluid balance and immune defense. Hence, the lymphatic system stands out for its unique contributions to