Perineurium

Definition

The perineurium is a protective sheath of connective tissue that surrounds bundles of nerve fibers (fascicles) within peripheral nerves. It acts as a barrier to protect the nerve fibers from physical and chemical damage.

Related terms

Endoneurium:

A delicate layer of connective tissue that individually encases each axon within a nerve, providing further protection and support.

Epineurium:

The outermost layer of connective tissue surrounding an entire peripheral nerve, offering additional protection and strength to the nerve structure.

Nerve fascicle: A bundle of nerve fibers (axons) enveloped by the perineurium within a peripheral nerve