neuroanatomy 4

Question 1

CN I modality

Answer 1

purely sensory

Question 2

CN III

Answer 2

motor + para symp

Question 3

trigemnial nerve (V) function

Answer 3

somatosensation of face, proprioception associated with chewing, motor control (muscles of mastication, tensor tympani, mylohyoid, ant belly of digastric, tensor veli palatini)

Question 4

name the trigeminal sensory nuclei

Answer 4

mesencephalic nucleus (proprioception info from chewing 
muscles), pontine trigeminal nucelus (discriminitve touch, vibration), spinal nucleus (pain +temp). 
they form a long column of neurons that stretch from midbrain to upper 2 segments of cervical spine

Question 5

what is unusual about the mesencephalic nucleus

Answer 5

only site in the CNS where the cell bodies of the primary afferent neurons live inside the CNS. it is a retained sensory ganglion

Question 6

in the ventral trigeminal tract where do most fibres cross

Answer 6

midline, but some dont which mean bilateral representation of vibration, touch in cortex

Question 7

what is the only CN to exit posteriorly

Answer 7

trochlear

Question 8

where does the abducens exit

Answer 8

caudal pons

Question 9

where does hypoglossal exit

Answer 9

medulla

Question 10

why do 3,4,6,12 emerge close to the midline

Answer 10

reflects the location of their nuclei

Question 11

what CN nerves share the solitary nucleus + where is it

Answer 11

7,9,10. upper and lower medulla

Question 12

which CN nerves share the sup and inf salivatory nuclei

Answer 12

7,9.

Question 13

which CN nerves share the nucleus ambiguus + where is it

Answer 13

9,10. lower pons/upper medulla

Question 14

what is the corticobulbar tract

Answer 14

part of the pyramidal tract that is motor to cranial nerves

Question 15

what does the facial nerve do

Answer 15

motor - muscles of facial expression
para innervation to pterygopalatine and submandibular ganglia
taste (ant 2/3 tongue via c.tympani)

Question 16

what does glosso do

Answer 16

tactile sense, pain, temp from the post tongue pharangotympanic tube and upper pharynx
motor - one muscle - stylopharyngeus

Question 17

what does vagus do

Answer 17

tactile sense, pain, temp from pharynx, larynx, trachea, oesophagus, thoracic and abdominal viscera
taste (epiglottis)
para to ganglia serving thoracic and abdo viscera
motor - striated muscle of pharynx and larynx