T Level Biology Practice Test

The lymphatic system primarily consists of lymphatic vessels and lymph nodes. Lymphatic vessels are a network of tubes that transport lymph, a fluid that contains infection-fighting white blood cells, throughout the body. These vessels play a critical role in maintaining fluid balance by returning excess interstitial fluid back to the bloodstream. Lymph nodes are small, bean-shaped structures that act as filters for lymph. They contain immune cells that can help the body fight infections and other diseases. When there is an infection, lymph nodes can become swollen as they work to filter pathogens from the lymph and produce more immune cells to combat the infection. Together, these components of the lymphatic system help to support the immune response and maintain fluid homeostasis in the body. Understanding this key role helps illustrate why the lymphatic system is essential for overall health and how it interacts with other bodily systems.