Which is a primary function of the spleen?

The primary function of the spleen is the filtration of blood. The spleen acts as a crucial organ in the lymphatic system, where it filters out old and damaged red blood cells, removing them from circulation. This process helps to maintain healthy blood cell levels and contributes to recycling iron, which is essential for the production of new red blood cells.

Additionally, the spleen plays a role in the immune response by filtering out pathogens and presenting antigens to lymphocytes, leading to the activation of the immune response. While the production of lymphocytes, storage of blood, and regulation of blood pressure are also important physiological processes, they are not the primary functions of the spleen. The organ's primary role hinges significantly on its ability to filter and cleanse the blood, contributing to the overall homeostasis of the body.