Peripheral Nerve Injuries Flashcards
Which cells form a thin cytoplasmic tube around peripheral nerves?
Schwann cells
What is the name of the membrane that coats the axon of the nerve?
Endoneurium
What is the name of the membrane that coats the fascicle of the nerve?
Perineurium
What is the name of the membrane that coats the nerve?
Epineurium
Nerve fascicles are bundles of what?
Axons
What does a bundle of fascicles form?
Nerve
What is the fiber category with the fastest conduction speed?
Aα
What is the thinnest fiber category?
C
Which nerve fiber category carries sharp pain, very light touch and temperature sensation?
Aδ
What type of sensations do category C nerve fibers carry?
Dull, aching, burning pain and temperature sensation
Which nerve fiber category carries touch, pressure, vibration and joint position sensory axons?
Aβ
What is neurapraxia?
Temporary loss of motor and sensory function due to blockage of nerve conduction, lasting six to eight weeks before full recovery - often from blunt trauma or shock injuries. Nerve remains intact.
What is axonotmesis?
Peripheral nerve injury in which the axons and their myelin sheath are damaged but the endoneurium, perineurium and epineurium remain intact. Usually the result of a more severe crush or contusion than neurapraxia, mainly follows a stretch injury.
What is neurotmesis?
Peripheral nerve injury in which both the nerve and nerve sheath are disrupted - partial recovery may occur but complete recovery is impossible.
What are three classical conditions of nerve compression?
Carpal tunnel syndrome (median nerve at wrist)
Sciatica (spinal root by intervertebral disc)
Morton’s neuroma (digital nerve in 2nd or 3rd web space of forefoot)