muscle fiber

Answer 1

Muscle fibers are long, cylindrical cells that make up the muscle tissue in our bodies. They are responsible for contracting and relaxing to produce movement in our bodies. Each muscle fiber contains many myofibrils, which are the functional units of muscle contraction. Muscle fibers can be classified as either fast-twitch or slow-twitch, based on their ability to generate force and sustain activity. Fast-twitch fibers are better suited for quick, powerful movements, while slow-twitch fibers are better for endurance activities.