When the connective tissue at either end of amuscle narrows to attach the muscle to a bone, the connective tissue is calleda tendon. A tendon actually is continuous with the periosteum connective tissuethat is the outer layer of a bone. In this way, muscle connections to bone arevery strong. As its name infers, skeletal muscle isgenerally attached to bone, by means of tendons. Tendons are actually acontinuation of the connective tissue covering of a muscle with the connectivetissue covering of a bone.
Skeletal muscle comprises the familiar grossanatomic muscle organs.
Red andwhite muscle are subtypes of skeletal muscle, referring to the color of themuscle due to blood supply and also cellular amounts of myoglobin protein. Myoglobin binds oxygen very tightly, releasing the oxygen only when cell levelsof oxygen become very low. In this way myoglobin can be though of as a type ofcellular scuba tank. Fast twitchmuscle fibers are adapted for sprinting and strength, and also correspond towhite muscle. Slow twitch muscle fibers are adapted for endurance, andcorrespond to red muscle.