A nerve fascicle is enclosed by perineurium, a layer of fascial connective tissue.

[4][1][5] A main nerve trunk may contain a great many fascicles enclosing many thousands of axons.

[5] In the central nervous system a bundle of nerve fibers is called a nerve tract, and in neuroanatomy different tracts in the spinal cord are bundled into fasciculi such as the medial longitudinal fasciculus.

In the spinal cord fasciculi are bundled into columns called funiculi such as the anterior funiculus.

This article incorporates text in the public domain from page 728 of the 20th edition of Gray's Anatomy (1918) This neuroanatomy article is a stub.