The endomysium, meaning within the muscle, is a wispy layer of areolar connective tissue that ensheaths each individual muscle fiber. It also contains capillaries and nerves. 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.