Beinagrindarvöðva

Beinagrindarvöðva, known in English as skeletal muscle, is one of the three major muscle tissues in the body, alongside cardiac and smooth muscle. It is responsible for voluntary movement, allowing us to walk, run, lift, and perform countless other physical actions. Skeletal muscles are attached to bones by tendons, and their contraction and relaxation are controlled by the nervous system.

The structure of skeletal muscle is characterized by its striated appearance, meaning it has a striped or banded look. This striation is due to the arrangement of contractile proteins, actin and myosin, within the muscle fibers. These fibers are long, cylindrical cells that contain multiple nuclei. The coordinated action of these fibers allows for the generation of force and movement.

Skeletal muscles are essential for maintaining posture, stabilizing joints, and generating heat. They are also involved in breathing, as muscles like the diaphragm and intercostal muscles are skeletal. The body contains over 600 individual skeletal muscles, each with a specific function. Training and exercise can increase the size and strength of skeletal muscles, a process known as hypertrophy. Conversely, disuse can lead to atrophy, a reduction in muscle mass and strength.