Sphingomyelin is a type of phospholipid found in cell membranes, particularly in the membranes of nerve cells. It plays a crucial role in maintaining the structure and function of these membranes. Sphingomyelin is composed of a sphingosine backbone, a fatty acid, and a phosphate group, which contributes to its unique properties. This lipid is important for the formation of myelin, a protective sheath that surrounds nerve fibers, facilitating efficient signal transmission. Sphingomyelin is also involved in various cellular processes, including cell signaling and apoptosis, making it essential for overall cellular health and function.