Part 2/14:
In vertebrates, the muscular system integrates with the skeletal system to form the musculoskeletal or musculoskeletal system, essential for movement in animals. Skeletal muscles, often called muscles, are organs that attach predominantly to bones via tendons, facilitating voluntary actions such as lifting, walking, and precise movements. These muscles are characterized by long, multinucleated cells known as muscle fibers, which are striated—meaning they display a striped appearance due to their internal organization.