Cranial Nerves And Compariso Flashcards
Cranial nerve attached to brainstem, uppermost spinal cord
At irregular intervals (unlike regular intervals that spinal nerve exit spinal cord in)
Describe cranial nerves
Bundled nerve fibers
Covered by myelin and connective tissue
Cranial nerves exit at
Brainstem through foramina of the skull
Serve muscles/organs of head, neck
Some motor only
Some sensory only
Some mixed
Some bilateral or contralateral innervation
Corticospinal vs corticobulbar start
Both start umn in primary motor cortex
Spinal versus bulbar where need up
Spinal- level of spinal cord whee desired muscle is
Bulbar- brainstem motor cranial nerve nuclei cns
Spinal vs bulbar next
Spinal- anterior horn/alpha motor neuron in the spinal cord
Bulbar- lower motor neuron in brainstem (cns)
Spinal vs bulbar next
Spinal- ventral root (motor) which exit, form spinal nerve (pns)
Bulbar- cranial nerve in pns
Spinal vs bulbar Innervate
Spinal- desired muscle on contralateral side
Bulbar- the desired muscle for speech- only those for lower half of face are contralateral
Describe reflex arc
Automatic “stimulus response” mechanism
Survival
Subconscious muscle control
Rapid response to potentially dangerous stimuli
Reflex arc works without having to send
Sensory info through afferent tracts all the way up to the cns to secure some kind of response
Reflex arc interneuron
Synapse with LMN and send info up to cns to process
Look at steps for reflex arc
Now