20.5: Skeletal Muscle Anatomy
Skeletal muscles—striated tissues under the voluntary control of the somatic nervous system—are attached to bones through collagenous fibers called tendons. They are enclosed in a connective tissue called epimysium, which distinguishes the muscle from surrounding structures.
Within each skeletal muscle, like the biceps brachii, are numerous cell bundles—fibers called fascicles—that are also surrounded by connective fascia, perimysium.
Each fascicle contains multiple muscle cells, which are individually enclosed in a plasma membrane known as the sarcolemma.
A single muscle cell can be further broken down into myofibrils—filaments composed of actin and myosin—the functional unit referred to as the sarcomere.