PNS Flashcards
Upper motor neuron lesions are located?
proximal to the anterior horn.
Lower motor neuron lesions are located?
Cell bodies or axons of lower motor neurons.
How many cranial nerves are there?
12
How many spinal nerves? Cervical? Thoracic? Lumbar? Sacral?
31 pair, 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygial
Signs of Upper motor neuron lesions?
Paralysis with spacticity, hyperflexia, +babinski, clonus (Rapid contraction and relaxation)
Signs of lower motor neuron lesions?
Flaccid paralysis, MM atrophy, fasciculations (twitch) and fibrillations (irreguloar spasm), hypoflexia
Reflex arc?
AFF N—-> spinal cord—-> back out to pns
Where do the thoracic nerves start?
below t-1
How many nerve roots at each level?
4
Why do the nerves split into root on each side of the vertebral column?
For protection (redundancy)
What info do posterior columns of the SC carry?
Proprioception, pressure, and vibration
Posterior horn carrys ____ impulses?
Sensory/afferent
Anterior horn carrys _____ impulses?
Motor/efferent
What does the brain stem control?
Ans/ breath/HR
What are the formations involved in the brachial plexus before the nerves become peripheral nerves? ie. Musculocutaneous, radial, ulnar, etc.
Roots, trunks, divisions, cords, and peripheral nerves. In that order.
