Cranial Nerves (Sensory)

Question 1

Which types of fibers are closest to the sulcus limitans in the brainstem and spinal cord?

Answer 1

Visceral Fibers

SVE/SVA in brainstem and GVE/GVA in spinal cord

Question 2

Where are sensory fibers located in the brainstem?

Answer 2

lateral (alar plate opens up)

Question 3

Where are sensory fibers located in the spinal cord?

Answer 3

posterior to the sulcus limitans

Question 4

How does sensory information from the nose reach the brain structures?

Answer 4

Send fine axons through cribriform plate to synapse in the olfactory bulb → axons of projection neurons in bulb travel as olfactory tract to synapse in olfactory cortex, amygdala, and related forebrain structures

Question 5

Axons of what cell type make up the optic nerve?

Answer 5

retinal ganglion cells

Question 6

What percent of optic nerve fibers cross over int he optic chiasm?

Answer 6

50%

Question 7

What are the two paths of the Optic Tract?

Answer 7

• Lateral geniculate body (visual thalamus) which projects to the primary visual cortex (around the calcarine fissure)
• Brachium of the superior colliculus to synapse there for startle reflexes

Question 8

Where is the chief sensory nucleus of V?

Answer 8

rostral pons

Question 9

What fibers feed into the chief sensory nucleus of V?

Answer 9

V, VII, IX

Question 10

What type of sensation is brought back to the chief sensory nucleus of V?

Answer 10

Epicritic = fine touch/ vibration sensations

Question 11

CN V afferent fibers feeding in to the chief sensory nucleus of V are from what ganglion?

Answer 11

Trigeminal Ganglion

Question 12

CN VII afferent fibers feeding in to the chief sensory nucleus of V are from what ganglion?

Answer 12

Geniculate Ganglion

Question 13

CN IX afferent fibers feeding in to the chief sensory nucleus of V are from what ganglion?

Answer 13

Inferior and Superior Glossopharyngeal Ganglion

Question 14

What happens after fibers from V, VII, and IX synpase int he chief sensory nucleus of V?

Answer 14

secondary neurons travel to the contralateral Trigeminal Leminiscus to the VPM of Thalamus→ Primary somatosensory cortex

Question 15

CN V carries epicritic information from where to the chief sensory nucleus?

Answer 15

face

Question 16

CN VII carries epicritic information from where to the chief sensory nucleus?

Answer 16

around the ext. auditory meatus

Question 17

CN IX carries epicritic information from where to the chief sensory nucleus?

Answer 17

Posterior 1/3 tongue, pharynx, tonisls, tympanum, and small area of external ear

Question 18

What is the only instance in which primary sensory neurons (pseudounipolar) reside within the CNS instead of a peripheral ganglion?

Answer 18

Mesencephalic Nucleus

Question 19

What information is passed to the mesencephalic nucleus?

Answer 19

Proprioceptive information from muscles of mastication

Question 20

What does the mesencephalic information do with the proprioceptive information?

Answer 20

Passes it to the reticular formation, cerebellum, and motor nucleus of V (stretch reflexes).

Question 21

Where is the spinal nucleus of V?

Answer 21

extends from mesencephalon to spinal cord to be continuous with substantia gelatinosa

Question 22

What information is carried to the spinal nucleus of V?

Answer 22

Pain and temperature afferents (protopathic)

Question 23

What fibers synapse at the spinal nucleus of V? What somatotopy?

Answer 23

Afferents from V1 (anterior)
Afferents from V2
Afferents from V3
Afferents from VII, IX, and X (posterior)

Question 24

CN V afferent fibers feeding in to the spinal nucleus of V are from what ganglion?

Answer 24

Trigeminal Ganglion

Question 25

CN VII afferent fibers feeding in to the spinal nucleus of V are from what ganglion?

Answer 25

Geniculate Ganglion

Question 26

CN IX afferent fibers feeding in to the spinal nucleus of V are from what ganglion?

Answer 26

Inferior and Superior Glossopharyngeal

Question 27

CN X afferent fibers feeding in to the spinal nucleus of V are from what ganglion?

Answer 27

Inferior and Superior Vagal

Question 28

What happens with fibers after synpasing at the spinal nucleus of V?

Answer 28

secondary fibers pass the contralateral Trigeminothalamic tract to the VPM of Thalamus→ Primary somatosensory cortex

Question 29

CN V carries protopathic information from where to the spinal nucleus of V?

Answer 29

face

Question 30

CN VII carries protopathic information from where to the spinal nucleus of V?

Answer 30

around the ext. auditory meatus

Question 31

CN IX carries protopathic information from where to the spinal nucleus of V?

Answer 31

posterior 1/3 tongue, pharynx, tonsils, tympanum, small bit of external ear

Question 32

CN X carries protopathic information from where to the spinal nucleus of V?

Answer 32

small bit of external ear

Question 33

Which CN ganglia is responsibe for receiving taste afferents?

Answer 33

Gustatory Nucleus (rostral Nucleus Solitarius in medulla)

Question 34

What CN fibers feed in to the Gustatory Nucleus?

Answer 34

CN VII, IX, and X

Question 35

CN VII carries taste information from where to the gustatory nucleus?

Answer 35

anterior 2/3 of tongue

Question 36

CN IX carries taste information from where to the gustatory nucleus?

Answer 36

posterior 1/3 of tongue

Question 37

CN X carries taste information from where to the gustatory nucleus?

Answer 37

pharynx and epiglottis

Question 38

CN VII afferent fibers feeding in to the gustatory nucleus are from what ganglion?

Answer 38

geniculate

Question 39

Where do secondary fibers go after synapsing in the gustatory nucleus?

Answer 39

Go to the ipsilateral VPM→ somatosensory cortex for taste

Question 40

What CN nucleus is responsible for chemo- and baro-reception sensing?

Answer 40

Cardiorespiratory Nucleus (caudal Nucleus Solitarius)

Question 41

What CN fibers feed to the Cardiorespiratory Nucleus?

Answer 41

CN IX and X

Question 42

CN IX carries visceral information from where to the cardiorespiratory nucleus?

Answer 42

Carotid Body (chemoreceptors) and Carotid Sinus (baroreceptors)

Question 43

CN X carries visceral information from where to the cardiorespiratory nucleus?

Answer 43

Aortic Arch (stretch receptors) and Aortic Bodies (chemoreceptors)

Question 44

Where do secondary fibers go after synpase int he cardiorespiratory nucleus?

Answer 44

Reticular formation and hypothalamus for reflex responses

Question 45

What nucleus receives input from inferior and superior vagal ganglion neurons that carry sensation from pharynx and larynx?

Answer 45

spinal nucleus of V

Question 46

Where is the vestibular nuclei?

Answer 46

pons and rostral medulla—near floor of the 4th ventricle

Question 47

Where are the afferents going to the vestibular nuclei located?

Answer 47

Hair Cells in saccule, utricle & 3 semiciruclar canals which synapse on cells in the vestibular (Scarpa’s) ganglion

Question 48

How many vestibular nuclei are there?

Answer 48

4: Lateral, Medial, Inferior, and Superior

Question 49

Fibers from which vestibular nuclei make up the Lateral Vestibulospinal tract?

Answer 49

lateral

Question 50

Fibers from which vestibular nuclei make up the Medial Vestibulospinal tract?

Answer 50

medial and inferior

Question 51

Fibers from which vestibular nuclei make up the MLF?

Answer 51

medial and superior

Question 52

The lateral vestibulospinal tract carries what information?

Answer 52

Balance and Extensor tone

Question 53

The medial vestibulospinal tract carries what information?

Answer 53

Control of head and neck position

Question 54

The MLF carries information for what?

Answer 54

coordinating eye movements

Question 55

Where is the cochlear ganglia?

Answer 55

pons

Question 56

Where are the afferents going to the cochlear nuclei located?

Answer 56

Hair Cells in the Organ of Corti (cochlea= inner ear) with body in the spiral ganglion.

Question 57

Where do secondary fibers from the cochlear nuclei go?

Answer 57

Auditory pathways ascend bilaterally to inferior colliculus → medial geniculate → Heschel’s gyrus (superior temporal lobe) for hearing