The muscle membrane, also known as the sarcolemma, is a thin, flexible barrier that surrounds muscle fibers. It plays a crucial role in maintaining the integrity of the muscle cell and facilitating communication between the cell and its environment. The membrane is composed of a lipid bilayer, which helps regulate the movement of ions and nutrients in and out of the cell. In addition to its protective function, the muscle membrane is involved in the transmission of electrical signals. When a nerve impulse reaches a muscle, it triggers changes in the membrane's permeability, allowing ions to flow in and out. This process is essential for muscle contraction and overall muscle function.