What is the main function of the spleen?

The main function of the spleen is to filter blood and help fight infections. This organ plays a crucial role in the immune system by identifying and removing old or damaged red blood cells from circulation, as well as serving as a site for the production and storage of white blood cells, which are vital for responding to infections. The spleen helps to filter out pathogens and contributes to the body's immune response by producing antibodies and activating lymphocytes, which are key components in defending against infection.

The other functions listed are performed by different organs in the body. Insulin production is the job of the pancreas, bile storage is conducted by the gallbladder, and blood pressure regulation is primarily managed by the heart and blood vessels. Understanding these functions helps clarify the specific and vital role the spleen plays in maintaining blood health and supporting the immune system.