What is Sarolemma?
Sarolemma, also called myolemma, is a cell membrane of the muscle cell. Cells of all types of muscles in the human body - skeletal, heart and smooth muscle - all have sarcaremmy. The cell membrane or plasma membrane is an important structure of all cells. It is built of lipids, proteins and carbohydrates and is used to separate the interior of the cell from the external environment and selectively allows substances to and out of the cell. Sarolemma is a specialized type of cell membrane that solves the unique needs of muscle cells.
Sarolemma differs from other cell membranes in that it has two layers. The layer closest to the inside of the cell is the same as the other cell membranes, while the outer layer consists of polysaccharides with thin collagen fibers. In the skeletal muscles, at the end of each muscle fiber, the outer layer of sarcolemma with the tendon fibers is connected and provides the connection of the muscles to the skeleton through the tech.
In addition to protection functions and selective permeability common to all cell membrantsOna, sarcolemma also serves to accept and perform stimuli necessary for muscle contraction. In skeletal and heart muscles, sarcolemma tubules are deep inside the muscle cell known as transverse tubules or t-tubules, which allow chemical changes to polarity to quickly penetrate into the interior of the cell. These changes in polarity, called action potential, are what muscle contractions control.
In some forms of hereditary muscle disease, muscle dystrophy, progressive muscle weakness is caused by incorrectly functioning sarcolemma. In some forms of the disease, the patient lacks protein dystrophin, which exists in very small quantities in skeletal muscles in healthy individuals. This deficiency causes the cell membrane to be released by the cytoskeleton, an intracellular structure that maintains the shape of the cell. As a result, too many calcium channels open during muscle contractionů, causing the excess of the calcium to flood the cell. The excess of calcium ions activates the enzyme calpain, which spends proteins, causing a weaker muscle.