Which of the following organs is part of the lymphatic system?

The spleen is part of the lymphatic system, which plays a crucial role in the immune response and the maintenance of bodily fluid levels. Specifically, the spleen filters blood, removing old or damaged red blood cells and pathogens, which helps to protect the body from infection. It stores white blood cells and other immune cells, enabling the body to respond quickly to infections. In contrast, the brain, liver, and lungs do not have this specific function within the lymphatic system; they are part of other systems in the body, such as the nervous system, digestive system, and respiratory system, respectively. Understanding the role of the spleen enhances comprehension of the lymphatic system's importance in overall health and immune function.