Endomysium

The endomysium, meaning within the muscle, is a layer of connective tissue that ensheaths a muscle fiber and is composed mostly from reticular fibers. It also contains capillaries, nerves, and lymphatics. It overlies the muscle fiber's cell membrane: the Sarcolemma.

The term cardiac skeleton is sometimes considered synonymous with endomysium, but sometimes cardiac skeleton refers to the combination of the endomysium and perimysium.

Anti-endomysial antibodies (EMA) are present in celiac disease. They do not cause any direct symptoms to muscles, but detection of EMA is useful in the diagnosis of the disease.