Sarcomere

A sarcomere is the basic structural and functional unit of a muscle, responsible for muscle contraction. It is a repeating segment within muscle fibers, composed of overlapping protein filaments called actin and myosin. When a muscle contracts, these filaments slide past each other, shortening the sarcomere. This coordinated shortening of many sarcomeres along a muscle fiber leads to overall muscle contraction. Think of sarcomeres as tiny repeating units that work together like a row of motors to produce movement and force in your muscles.