Anatomy - CN VII-XII Flashcards Preview

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Flashcards in Anatomy - CN VII-XII Deck (43):

All general somatic sensory fibers synapse on ___

Cells of the trigeminal complex

Does not matter which Cranial Nerve they are in


All taste sensory fibers terminate in __

The rostrum half of the solitary nucleus


All general visceral sensory fibers terminate in ___

The caudal half of the solitary nucleus


Special sensory fibers serving audition and vestibular sense synapse on ___

Specific nuclei of he brainstem


Somatic motor neurons arise from ___

Discrete motor nuclei

Arranged in a rostral-caudal order within the brainstem


Preganglionic parasympathetic fibers are found in which nerves?

Facial n.
Glossopharyngeal n.
Vagus n.


The preganglionic parasympathetic sonata are in ___ nuclei

Pontine and



Facial n.
Muscles of facial expression


Somatic motor neurons of CN VII are in the facial motor nucleus of the __

General pathway?


Axons leave CN VII and course through the temporal bone and middle ear cavity (innervates stapedius here) before exiting the base of the skull

Innervates stylohyoid and p. belly of digastric as it exits the skull

Enters parotid gland and divides into 5 branches


CN VII is also a source of preganglionic and parasympathetic control of __

Glands in the head

Preganglionic cell bodies are in the superior salivatory nucleus of the medulla


Greater petrosal n.

Some fibers of CN VII diverge at geniculate ganglion

They pass anteriorly across middle cranial fossa
Enters pterygopalatine fossa
Synapse in pterygopalatine ganglion


Chorda tympani

Some CN VII fibers leave as it passes through the middle ear

Joins lingual n. in the infratemporal fossa


Preganglionic fibers of chorda tympani synapse in the ___

Submandibular ganglion


What do postganglionic parasympathetic fibers of chorda tympani do?

control secretion from submandibular and sublingual salivary glands


What supplies visceral sensation of taste to the anterior two-thirds of the tongue?

Where are these neurons located? Where do they synapse?

Sensory fibers in CN VII

Located in a ganglion in the temporal bone

synapse on rostral half of solitary nucleus in the brainstem


CN VII is also involved in somatic sensation to which three areas?

Where are these sensory cell bodies located?

external auditory canal
a small area in the oropharynx

Located in the geniculate ganglion, synapse on cells of the trigeminal sensory complex


CN VIII ? Receives input from? Where do central processes go?


Receives input from auditory and vestibular apparatuses

Central processes go into brainstem


CN IX functions


2 motor, 3 sensory


Which CN innervates stylopharyngeus?


somatic motor neurons in nucleus ambiguus


Preganglionic parasympathetic cells in the salivatory nucleus of the medulla send axons to which CN?



Which part of the tongue does CN IX supply? What kind of innervation? What else gets this kind from this nerve?

Posterior tongue

General somatic sensation
-also to oropharynx and middle ear cavity


Path of preganglionic parasympathetic fibers of CN IX

Diverge from CN IX at the base of the skull

Enter and pass through middle ear cavity

Exits middle ear cavity as lesser petrosal n.

Synapses on postganglionic cells in optic ganglion deep in the infratemporal fossa

Postganglionic axons join auriculotemporal n. and innervate parotid salivatory gland


Sensory cell bodies of CN IX are located where?

for somatic sensation to posterior tongue, oropharynx, and middle ear cavity

Superior ganglion near the base of the skull


Sensory cell bodies of CN IX are located where?

For taste sensation to posterior tongue

Inferior ganglion near the base of the skull


Central processes end where?

for somatic sensation to posterior tongue, oropharynx, and middle ear cavity

On the chief sensory nucleus and/or spinal nucleus of trigeminal


Central processes synapse where?

For taste to posterior tongue

Rostral half of solitary nucleus


CN IX conveys general visceral sensory information concerning blood oxygen levels and blood reassure from receptors in the___

Sensory cell bodies are found __
Central processes synapse__

Carotid a.

Sensory cell bodies are found in the inferior ganglion of IX

central processes synapse on caudal half of solitary nucleus


CN X functions

Vagus n.
2 motor, 3 sensory functions


List of CN VII functions

1. Somatic motor to muscles of facial expression

2. Preganglionic parasympathetic control of glands in the head

3. Visceral sensation of taste to anterior 2/3 of tongue

4. Limited somatic sensation to external auditory canal and small area of oropharynx


List of CN IX functions

1. Somatic motor to stylopharyngeus

2. Parotid salivary gland

3. Limited general somatic sensation to posterior tongue, oropharynx, and middle ear cavity

4. Taste sensation to posterior 1/3 of tongue

5. Visceral sensory info about blood oxygen levels and BP from carotid a.


List of CN X functions

1. Somatic motor to most of the muscles in the pharynx and larynx

2. Preganglionic parasympathetic to organs of thorax and abdomen to the level of the left colic flexure

3. General visceral afferents for functional status of thoracic and abdominal organ systems

4. General sensation and taste to small part of posterior tongue and pharyngeal wall


CN X cell bodies for preganglionic parasympathetic organ innervation are located ___

Dorsal motor nucleus of X in the medulla


Somatic motor neurons in nucleus ambiguus send axons in CN X to innervate ___

Most of the muscles of the pharynx and larynx


CN X sensory cell bodies for visceral afferents that convey functional info of thorax and abdomen are located ___

Where do centralbprocesses synapse?

Inferior ganglion of X near the base of the skull

Central processes synapse on the cells in the caudal solitary nucleus


CN X sensory cell bodies for taste are located ___ and central processes synapse ___

Superior and inferior vagal ganglia

Cells in the trigeminal spinal nucleus and solitary nucleus respectively


Patients with vagal dysfunction often present with__

Low and soft voice

Aspirating fluids or food

Asymmetrical elevation of soft palate


CN XI functions

Spinal Accessory n.

Strictly motor to trapezius and SCM


Somatic motor neurons of CN XI are located ___

Pathway __

Central horn at C1-C4 levels of the spinal cord

Axons exit the lateral surface of the cervical cord

Pass through foramen magnum INTO THE SKULL

Axons leave the skull through jugular foramen


CN XII function

Hypoglossal n.

Only one function: innervates all intrinsic and extrinsic muscles of the tongue EXCEPT palatoglossus (which is by CN X)


Pathway of CN XII

Axons arise from neuronal somata of the hypoglossal nucleus

Exit the brainstem

Pass through hypoglossal canal

Pass anteriorly to enter the deep floor of the mouth


How do you test CN VII?

Test contraction of superficial facial muscles from frontalis to platysma

Pt could also complain of:
dry eye
Loss of taste to anterior 2/3
loss of eye abduction

All ipsilateral


How do you test CN IX?

Stimulate oropharynx to elicit gag reflex
-could be false positive (facial and vagus nerves also in that area)

Touch and taste to posterior tongue


Glands that CN VII innervates

Mucous glands of nasal cavity
Submandibular salivary
Sublingual salivary