Anatomy - CN VII-XII Flashcards
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
Medullary
CN VII
Facial n.
Muscles of facial expression
Somatic motor neurons of CN VII are in the facial motor nucleus of the __
General pathway?
Pons
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
ear
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?
Auditory/Vestibulocochlear
Receives input from auditory and vestibular apparatuses
Central processes go into brainstem
CN IX functions
Glossopharyngeal
2 motor, 3 sensory
Which CN innervates stylopharyngeus?
CN IX
somatic motor neurons in nucleus ambiguus
Preganglionic parasympathetic cells in the salivatory nucleus of the medulla send axons to which CN?
CN IX
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
- Somatic motor to muscles of facial expression
- Preganglionic parasympathetic control of glands in the head
- Visceral sensation of taste to anterior 2/3 of tongue
- Limited somatic sensation to external auditory canal and small area of oropharynx
List of CN IX functions
- Somatic motor to stylopharyngeus
- Parotid salivary gland
- Limited general somatic sensation to posterior tongue, oropharynx, and middle ear cavity
- Taste sensation to posterior 1/3 of tongue
- Visceral sensory info about blood oxygen levels and BP from carotid a.
List of CN X functions
- Somatic motor to most of the muscles in the pharynx and larynx
- Preganglionic parasympathetic to organs of thorax and abdomen to the level of the left colic flexure
- General visceral afferents for functional status of thoracic and abdominal organ systems
- 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
Lacrimal
Mucous glands of nasal cavity
Submandibular salivary
Sublingual salivary
