The lymphatic system and immunity are intricately linked in that the lymphatic system is an important part of the immune system. The immune system is a group of organs and associated structures that help protect the body from possible intruders. These intruders come in the form of foreign bodies, most typically referred to as antigens. The immune system also protects against viruses and any other threats to the health of an individual. The lymphatic system and immunity are correlated in these protective processes.
To best understand the relationship between the lymphatic system and immunity, it is important to develop an understanding of each system individually. The lymphatic system can be broken down into components. The involved structures include lymph nodes and trunks. When interstitial fluid needs to return to the heart, it must pass through these structures. The lymph system acts as a filter before the fluid is eventually returned to the heart. Additionally, this system produces lymphocytes.
Lymphocytes are the active part of the lymph nodes, which act to defend against the potentially dangerous microorganisms. If these organisms and foreign bodies manifest themselves in a person's blood or other fluid, it is eventually circulated through lymph nodes. This is the point at which lymphocytes act to rid the body of harmful agents before returning the filtered fluid to the heart for circulation. There are six primary node locations distributed throughout the body in a way that covers most regions evenly.
After fluid flows through the filtering nodes, it drains to larger lymphatic trunks before eventually finding one of two major ducts on its way to the great veins that lead to the heart. This draining sequence allows for potentially impure, adulterated fluid from all bodily regions to reach the central circulation system in a purified fashion.
Immunity is important to keeping humans alive. There exist in this universe an incredibly high number of harmful creatures and organisms, all focused on survival themselves. Their survival mechanisms sometimes target other beings, like humans, in the process, and this creates a dangerous environment from which humans need to be protected. Thankfully, the body has developed a number of ways to combat such potential harm. The lymphatic system and immunity work together in achieving the level of safety necessary to maximize the chance of survival for the human species.