How many paris of spinal nerves are there compared to cranial nerves?
31 pairs of spinal nerves
12 pairs of cranial nerves
How do spinal nerves and cranial nerves differ in their fiber content?
1. spinal nerves are mixed - motor and sensory
2. cranial nerves can be mixed, only motor, or only sensory
What 2 cranial nerves are actually tracts because they don't have nuclei - they just stay in the brain?
Cranial nerves 1 and 2
What is the only CN that comes out the dorsal side of the brain?
What eye muscle is controlled by the trochlear nerve?
What eye muscle is controlled by the abducens nerve?
the lateral rectus - controls eye movement in a horizontal plane
How many nerves are associated with the forebrain, midbrain, pons, or medulla respectively?
2 with the forebrain (1 and 2)
2 with the midbrain (3 and 4)
4 with the pons (5-8)
4 with the medulla (9-12)
In general, how are nerves arranged based on embryological development?
the alar plate has sensory fibers and the basal blate as motor fibers
as the medulla upens up , the plates go with it so that the alar (sensory) is lateral while the basal (motor) is medial
These are separated by the sulcus limitans and viseral innervarion is located near the sulcus
WHat does the inferior colliculus do? How about the superior colliculus?
inferior = audition
superior = ocular revlexes
What do fibers do at the pyramidal decussation?
they cross over to the other side
What are pattern generators, and how can they occur?
It's an "autopilot" type of coordinated response which is activtated when a command domes down from the motor cortex to the brainstem neurons
It's possible because th eneurons are wired together in such a way that pools of neurons are activated in the right order and timing to make the response occur
(examples are chewing, swalowing, breathing, etc)
What ist he "packing material" of the cranial nerve nuclei?
the reticular formation
If the caudal medulla looks like a squished spinal cord, what is the "dorsal horn" area associated with?
the trigeminal nerve
WHat type of sensation if the medial lemniscus associated with?
proprioceptive, light touch, vibration
What types of touch are associated with the spinal thalamic tract?
pain and temperature
What is the corticospinal tract associated with? Where does it cross/
crosses at the pyramidal decussation