The Musculoskeletal System

The musculoskeletal system has many functions to it because it is actually two systems that are put together; muscular and skeletal. The organs that are in these systems are skeletal muscles, bones (joints, tendons, and ligaments). By dividing the two systems into different sections, it will make it easier for you, the reader, to understand and make sense of the information. The muscular system functions are to provide movement, protects organs, and production of heat. There are many muscles that do different functions. Before I go into all of the muscular functions, I will give an overview of all the muscle structure. Fascia, which is a fibrous connective tissue, separates an individual skeletal muscle from adjacent muscles and then holds it into position. Fascia surrounds each muscle and protects beyond the end of its muscle fibers to form a tendon. The aponeuroses tissues are the forms broad fibrous sheets that attach to the coverings of adjacent muscles. The epimysium lies beneath the fascia, the perimysium extends into the structure of the muscle, where muscle cells separate into fascicles. Endomysium separates individual muscles fibers. Skeletal muscle fibers contract in response to stimulation and then relax when the stimulation ends. Threadlike structures called myofibrils run lengthwise throughout the muscle fiber. The myofibrils are composed of two types of even tinier structure, the myofilaments. The thick myofilaments called myosin filaments consist mainly of the protein myosin. The actin filaments consist of the protein actin. Myosin and actin filaments are arranged lengthwise in the muscle fibers so that they overlap. During muscle contaction, the actin filaments are pulled inward between the myosin filaments. As that occurs; a nerve cell that stimulates a muscle releases a compound known as acetylcholine. The acetylcholine goes across the muscle-nerve and combines with receptors on the surface of the muscle cell. Then the electrical current