Which organ is primarily responsible for filtering blood and producing lymphocytes?

The spleen is primarily responsible for filtering blood and producing lymphocytes, which are vital components of the immune system. Located in the upper left part of the abdomen, the spleen filters out old or damaged red blood cells from the bloodstream and helps recycle iron. Additionally, it plays a crucial role in the body's immune response by producing lymphocytes—specifically B cells and T cells—that help recognize and fight infections.

Understanding the spleen's dual functions highlights its significance in both blood filtration and immune defense, making it an essential organ in maintaining the body’s overall health. The focus on these functions aligns with the role of lymphocytes in identifying pathogens, indicating the spleen's pivotal place in immune system operations.