A muscle fascicle is a bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue.

[1] Fascicles are bundled together by epimysium connective tissue.

[2] In the heart, specialized cardiac muscle cells transmit electrical impulses from the atrioventricular node (AV node) to the Purkinje fibers – fascicles, also referred to as bundle branches.

[3] Muscle fascicle structure is a useful diagnostic tool for dermatomyositis.

Myocytes towards the edges of the muscle fascicle are typically narrower, while those at the centre of the muscle fascicle are a normal thickness.