The structure indicated in this diagram is the epimysium.
Skeletal muscle fibres are organised into bundles, called fascicles
. Each fibre within the fascicle is surrounded by connective tissue called endomysium
. Surrounding each fascicle (bundle), is the perimysium
. Extensions of the perimysium project into the fascicles to blend with the endomysium. Surrounding the groups of fascicles is the epimysium
, which covers the outer surface of the muscle. The epimysium is composed of dense irregular connective tissue
. The epimysium can extend beyond the fleshy muscle fibres to form tendons or aponeuroses
, which then form attachments to the periosteum