Lecture 7, Cranial Nerves

Question 1

Cervicomedullary junction

Answer 1

foramen magnum and pyramidal decussation
caudal limit of brainstem

Question 2

Midbrain-diencephalic junction

Answer 2

brainstem meets the thalamus and hypothalamus at the level of the tentorium cerebelli

Question 3

Hypoglossal trigone/vagal trigone

Answer 3

formed by the hypoglossal nucleus and dorsal motor nucleus of vagus

Question 4

Facial colliculi

Answer 4

formed by the abducens nuclei and fibers of the facial nerve

Question 5

The pons is attached to the cerebellum by

Answer 5

large white matter tracts called superior, middle, and inferior cerebellar peduncles

Question 6

Motor cranial nerve nuclei are located

Answer 6

more ventrally

Question 7

Sensory cranial nerve nuclei are located

Answer 7

more dorsally

Question 8

Somatic motor nuclei

Answer 8

CN 3, 4, 6, 12
derived from occipital somites
extraocular muscles, intrinsic tongue muscles

Question 9

Visceral motor nuclei

Answer 9

made up of branchial motor nuclei and parasympathetic nuclei

Question 10

Branchial motor nuclei

Answer 10

CN 5, CN 7, 9, 10, 11
innervate striated muscles
muscles of mastication, facial expression, middle ear, pharynx, larynx, SCM, traps

Question 11

Parasympathetic motor nuclei

Answer 11

CN 3, 7, 9, 10
do not innervate striated muscle, but innervate glands, smooth muscle, cardiac muscle

Question 12

Visceral sensory column

Answer 12

made of 2 parts
rostral nucleus solitarius
caudal nucleus solitarius

Question 13

Rostral nucleus solitarius

Answer 13

receives taste inputs primarily from CN 7, 9, 10

Question 14

Caudal nucleus solitarius

Answer 14

receives inpt to regulate cardiac, respiratory, and GI function from 9 and 10

Question 15

General somatosensory nuclei/trigeminal

Answer 15

mediate touch, pain, temp, poisition and vibration sense for the face, sinuses, and meninges. Mostly CN 5 (7, 9, 10)

Question 16

Special somatic sensory

Answer 16

olfaction, vision, hearing, vestibular sensation
CN 8

Question 17

Special senses

Answer 17

olfaction, vision, hearing, vestibular sense, taste

olfaction and vision do not have their primary sensory nuclei in brainstem

Question 18

Olfactory Nerve

Answer 18

specialized chemoreceptors on bipolar primary sensory neurons

axons travel via olfactory nerves, synapse in olfactory bulbs, and travel through tracts. ends in temporal lobe

Question 19

Optic Nerve

Answer 19

carries visual info from retina to LGN nucleus of the thalamus

visual info travels in optic nerve from orbit to intracranial cavity via optic canal

Question 20

Edinger-Westphal

Answer 20

nucleus in the midbrain
these synapse on ciliary ganglion located in the orbit
postganglionic neurons then go to pupillary constrictor and ciliary muscles

Question 21

Mesencephalic nucleus

Answer 21

carry proprioceptive input from the muscles of mastication, tongue, and extraocular muscles

Question 22

Main/chief trigeminal sensory nucleus

Answer 22

provude sensory for the face and head that are analogous to posterior columns (DCML)

Question 23

Spinal trigeminal

Answer 23

provide sensory for the face and head that are analogous to the ALS

Question 24

Trigeminal Lemniscus pathway

Answer 24

Trigeminal ganglion–> main trigeminal sensory nucleus–> 2nd order decussates and ascends in trigeminal lemniscus –> syanpses on VPM in thalamus –> 3rd order leaves VPM –> internal capsule __> corona radiata –> S1

Question 25

Trigeminothalamic Pathway

Answer 25

Trigeminal ganglion--> spinal trigeminal tract__> spinal trigeminal nucleus--> trigeminothalamic tract --> VPM --> internal capsule --> corona radiata --> S1

Question 26

Mesencephalic Trigeminal Tract

Answer 26

Mesencephalic nucleus --> mesencephalic trigeminal tract --> main trigeminal sensory nucleus --> trigeminal lemniscus --> VPM --> internal capsule --> corona radiata --> S1

Question 27

Facial Nerve categories

Answer 27

Brancial motor parasympathetic visceral sensory, special somatic sensory

Question 28

Branchial Motor CN VII

Answer 28

muscles of facial expresion

Question 29

Parasympathetic CN VII

Answer 29

lacrimal glands, sublingual, submandibular, salivary glands besides parotid

Question 30

Visceral sensory CN VII

Answer 30

taste from 2/3 tongue

Question 31

General Somatic Sensory

Answer 31

sensation from samll region near ear

Question 32

Preganglionic Parasympathethic Fibers of CN VII

Answer 32

originate in superior salivatory nucleus

Question 33

CN VIII

Answer 33

special somatic sensory for hearing

Question 34

Summary of sound

Answer 34

sound enter the external auditory meatus, transmitted mechanically by middle ear to cochlea, transduced by hair cells to neural signals carried by cochlear nerve

Question 35

Dorsal Cochlear Nuclei

Answer 35

Spiral ganglion--> DCN--> crosses--> trap body--> inf colliculus--> MGN --> A1

Question 36

Ventral Cochlear Nuclei

Answer 36

Spiral ganglion--> VCN--> splits into 2 separate paths at pons 1. superior olivary--> inf colliculus--> MGN--> A1 2. Trapezoid body--> inf colliculus -->MGN--> A1