What is the function of the lymphatic system in relation to the immune system?

The lymphatic system plays a critical role in the immune system, primarily through its function of filtering pathogens. Lymph, the fluid transported by the lymphatic system, carries immune cells, including lymphocytes, throughout the body. As lymph circulates, it passes through lymph nodes, which are small, bean-shaped structures that act as filters. These lymph nodes trap bacteria, viruses, and other foreign substances, allowing immune cells to identify and respond to potential threats.

This filtration process is essential for the immune response, as it enables the body to detect and attack pathogens before they can cause harm. The lymphatic system not only helps remove pathogens but also facilitates the activation and proliferation of immune cells, thereby playing a crucial part in maintaining the body’s defense mechanisms.

The other functions mentioned, such as transporting oxygen or storing energy, do not pertain to the lymphatic system's role in immunity. The circulation of antibodies is also part of the immune response, but it is not the primary function of the lymphatic system. Instead, it is focused on the identification and removal of pathogens, which is why filtering pathogens is the correct answer.