Nerve fascicle

A nerve fascicle or fasciculus is a small bundle of axons (nerve fibres), enclosed by the perineurium; if the nerve is of small size, it may consist only of a single fascicle; but if large, the fascicles are collected together into larger bundles or funiculi, which are bound together in a common membranous investment. A nerve fascicle refers to nerves in the peripheral nervous system, in the central nervous system this is known as a tract.