Which system is primarily responsible for fighting bacteria and infection?

The lymphatic system is primarily responsible for fighting bacteria and infections within the body. This system plays a critical role in the immune response by transporting lymph, a fluid that contains infection-fighting white blood cells, throughout the body. The lymphatic system includes a network of lymph nodes, lymph vessels, and organs such as the spleen and thymus, which are all involved in filtering out pathogens, such as bacteria and viruses, and mounting an immune response.

When the body encounters pathogens, lymphocytes (a type of white blood cell) are activated, proliferate, and help to identify and destroy the invading organisms. Additionally, the lymphatic system helps return excess interstitial fluid to the bloodstream, which is essential for maintaining fluid balance and supporting the function of immune cells.

In contrast, while the digestive system processes nutrients and the integumentary system provides a physical barrier against pathogens, they do not specifically target infections like the lymphatic system does. The urinary system primarily deals with the excretion of waste products and the regulation of body fluids, making it less involved in directly combating infections.