Spleen (as a concept)

The spleen is an organ in the body, located in the upper left abdomen. It plays several important roles, including filtering blood, recycling iron from old red blood cells, and helping the immune system by producing white blood cells that fight infection. While it is not essential for survival, the spleen contributes to overall health by managing blood and fighting disease. In historical and literary contexts, "spleen" can also refer to a state of melancholy or irritability, reflecting a more emotional or psychological concept.