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Cranial Nerves
Dr. Huitt
177
Other
Graduate
03/12/2011

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Term
Provide motor and sensory innervation for the head and neck including innervation of voluntary and involuntary muscles and both general and special sensation.
Definition
Cranial Nerves
Term
Nerves innervating muscles of the head derived from somites
Definition
General Somatic Efferents (Somatic Motor)
Term
Nerves innervating muscles derived from the branchial (pharyngeal arches)
Definition
Special Visceral Efferents (Branchial Motor)
Term
Nerves innervating the viscera, including glands and all smooth muscle.
Definition
General Visceral Efferents (Visceral Motor)
Term
Nerves related to the "special" senses of vision, hearing, and equilibrium.
Definition
Special Somatic Afferents (Special Sensory)
Term
Nerves which carry general sensation from skin, muscles, joints, mucosa of structures in the head and neck.
Definition
General Somatic Afferents (General Sensory)
Term
Nerves which carry sensation from viscera
Definition
General Visceral Afferents (Visceral Sensory)
Term
Nerves which carry sensation from the special senses of taste and smell.
Definition
Special Visceral Afferents (Special Sensory)
Term
Upper motor neurons that provide cortical innervation for motor nuclei of cranial nervs V, VII, X, XI, and XII
Definition
Corticobulbar fibers
Term
These fibers innervate muscles of the face and head (except UMN are located near the lateral fissure of the brain and their axons converge in the corona radiata to form the corticobulbar tract)
Definition
Corticobulbar fibers
Term
These axons descend within the genu of the internal capsule to the medial part of the cerebral peduncle.
Definition
Corticobulbar fibers
Term
The upper motor neuron axons travel with the corticospinal tract, then synapse on lower motor neurons of the cranial nerve nuclei which are located in the midbrain, pons, and medulla.
Definition
Corticobulbar fibers
Term
Axons that project contralaterally cross at the level of the nuclei.
Definition
Corticobulbar fibers
Term
Where does the hypoglossal nerve exit?
Definition
Hypoglossal canal
Term
Provides motor to all of the intrinsic and most of the extrinsic muscles of the tongue (genioglossus, hypoglossus, styloglossus and geniohyoid)
Definition
Hypoglossal
Term
What type of innervation does the hypoglossal nerve receive?
Definition
GSE (Somatic Motor)
Term
Where are the cell bodies of origin located for the Hypoglossal nerve?
Definition
In the hypoglossal nucleus from the rostral to caudal medulla just beneath the floor of the 4th ventricle and forms an elevation called the Hypoglossal Trigone. Located medial to the dorsal motor nucleus of vagus nerve roughly coextensive with the olive.
Term
Where are the lower motor neurons for the Hypoglossal Nerve?
Definition
The axons pass ventrally on the ipsilateral side along the lateral side of the medial lemniscus. Emerge ont he ventral surface of the brainstem between the olive and pyramid as a number of rootlets.
Term
Where are the upper motor neurons for the Hypoglossal Nerve?
Definition
Most corticobulbar fibers project bilaterally from the primary motor cortex to innervate the hypoglossal nuclei. These fibers run with corticospinal fibers and provide conscious control of muscles of the tongue.
Term
What is the 1 exception for the UMN of the hypoglossal nerve.
Definition
Cortical neurons that drive genioglossus muscle project ONLY contralaterally
Term
What occurs if you have a LMNL in the hypoglossus at below the level of the nucleus.
Definition
Flaccid paralysis of the tongue with fasciculations and atrophy of the tongue muscles on affected side (over time). Upon protrusion of the tongue, the tongue will deviate toward the side of weakness with is the SAME side as the lesion
Term
What occurs if you have a LMNL at the level of the nucleus of the hypoglossal nerve.
Definition
Usually results in bilateral loss of innervation to tongue muscles due to close proximity of the nuclei within the brainstem. It is rare to affect only 1 nucleus and not the other because they are so close at the midline.
Term
What occurs if you have an UMNL of the hypoglossal nerve? (Motor cortex and below to the level of the nucleus)
Definition
Minimal atrophy and no fasciculations of tongue muscles. Upon protrusion of the tongue, the tongue deviates toward the side of weakness, which is the side OPPOSITE the lesion (due to contralateral innervation of the genioglossus)
Term
Where does the accessory nerve exit?
Definition
Jugular Foramen
Term
What muscles does the accessory nerve innervate?
Definition
SCM and Trapezius
Term
What type of innervation does the accessory nerve receive?
Definition
SVE (Branchial Motor)
Term
Where are the cell bodies of origin for the accessory nerve?
Definition
Upper 5 cervical segments of spinal cord - Accessory Nucleus
Term
Does the SCM turn the head toward the same or opposite side?
Definition
Opposite
Term
Where are the LMN of the accessory nerve?
Definition
Axons emerge from the lateral white matter of the spinal cord as a series of rootlets to form the accessory nerve, which enters the cranium thru the foramen magnum.
Term
What muscle elevates the UE and shrugs the shoulders?
Definition
Trapezius
Term
Where are the UMN for the accessory nerve?
Definition
Corticobulbar fibers from the contralateral (traps) and ipsilateral (SCM) motor cortex traveling with the corticospinal pathway. Provide conscious control of SCM and upper traps
Term
With UMN, are traps under ipsilateral or contralateral control?
Definition
Contralateral
Term
What presents if you have a LMNL of the accessory nerve?
Definition
Nucleus and below will result in weakness of the SCM and upper trapezius muscle ipsilaterally. Patients have inability to shrug shoulder, weakness with upward rotation of scapula, weakness rotating head to opposite side.
Term
What presents if you have a UMNL of the accessory nerve?
Definition
Ipsilateral SCM weakness (patients head turned toward site of lesion) and contralateral upper traps weakness
Term
If you have weakness in the SCM, is this an Upper or Lower motor neuron lesion?
Definition
This is not enough information to tell
Term
With UMN, is SCM under ipsilateral or contralateral control?
Definition
Ipsilateral.
Term
If you have weakness in the SCM and traps on the same side, is this an upper or lower motor neuron lesion?
Definition
LMNL
Term
If you have weakness in the right SCM and left traps (so on opposite sides), is this an upper or lower motor neuron lesion?
Definition
UMNL
Term
Patient presents with their head tilted down to the right (so face up to the left) with a droopy left shoulder. Is this an upper or lower motor neuron lesion?
Definition
LMNL
Term
What nerve runs from the brain stem to the splenic flexure of the colon?
Definition
Vagus
Term
What are the 2 ganglia that are situated on the vagus nerve?
Definition
Superior and Inferior Vagal Ganglia
Term
What provides innervation to the vagus nerve?
Definition
SVE (Branchial Motor), GVE (Visceral Motor), GVA (Visceral Sensory), and GSA (General Sensory)
Term
What is the function of the Branchial Motor (SVE) portion of the vagus nerve?
Definition
Provides motor to most of the striated muscles of the larynx and pharynx (except stylopharyngeus (IX) and tensor veli palatini (V3))
Term
Where are the cell bodies or origin for the branchial motor portion of the vagus nerve?
Definition
Nucleus Ambiguus - in medulla - just dorsal to the inferior olive
Term
Where are the LMN located for the branchial motor portion of the vagus nerve?
Definition
Exits the medulla of the brainstem dorsal to the olive as 8-10 rootlets caudal to CNIX. Converge as the vagus nerve and exit the cranium via the jugular foramen. Travels inferiorly int he neck within the carotid sheath to give branches (pharyngeal, superior laryngeal, and recurrent laryngeal)
Term
Where are the upper motor neurons located for the branchial motor portion of the vagus nerve?
Definition
Corticobulbar fibers from the premotor and motor cortex descend through the internal capsule to synapse on motor neurons in the nucleus ambiguus bilaterally
Term
What would occur if you had a LMNL in the branchial motor portion of the vagus nerve?
Definition
Nucleus Ambiguus or vagus n - hoarseness (unilateral loss of function of intrinsic muscles of larynx) and difficulty swallowing due to inability to elevate the soft palate adequately. Performed by observing the post. pharynx at rest and during phonation. Unilateral lesion of CNX causes deviation of the uvula and soft palate to the unaffected side due to unopposed action of the paryngeal constrictors
Term
What would present if you had an UMNL of the branchial motor portion of the vagus nerve?
Definition
Minimal symptoms due to bilateral corticobulbar innervation of the nucleus ambiguus
Term
What would present if you had an UMNL of the branchial motor portion of the vagus nerve?
Definition
Minimal symptoms due to bilateral corticobulbar innervation of the nucleus ambiguus
Term
This component of the vagus nerve is the motor arm of the gag reflex
Definition
Branchial Motor
Term
What is the function of the GVE (Visceral Motor) portion of the vagus nerve?
Definition
Preganglionic Parasympathetic innervation to the thoracic and abdominal viscera. Stimulation results in decreased HR, bronchoconstriction, and increased peristalsis.
Term
Where are the CBOs located for the visceral motor portion of the vagus nerve?
Definition
Dorsal motor nucleus of vagus nerve and medial portion of the nucleus ambiguus. These are preganglionic parasympatheic neurons. Dorsal motor nucleus of vagus lcoated in the floor of the 4th ventricle lateral to hypoglossal nucleus.
Term
Where are the LMN for the visceral motor portion of the vagus nerve?
Definition
Preganglionic axons emerge from the lateral surface of the medulla and travel in the vagus nerve. Supply parasympathetic innervation from pharynx/larynx as far as left colic flexure.
Term
Goes to the smooth muscle and glands of pharynx, larynx, and thoracic and abdominal viscera.
Definition
Dorsal Vagal Motor
Term
Goes to cardiac muscle
Definition
Nucleus Ambiguus
Term
What is the function of the GVA (Visceral Sensory) of the vagus nerve?
Definition
Receives information regarding general sensation (stretch, pressure, etc.) from viscera above the left colic flexure (pharynx, larynx, bronchi, lungs, heart, stomach, small intestine, and part of colon). Not assoc with conscious level of awareness other than "feeling good/bad" - unlike visceral pain carried in SNS. Also receives information from baroreceptors (stretch- monitors BP) in the aortic arch and chemoreceptors (monitor O2 tension in blood) in the aortic body.
Term
Area of the brainstem where you have a circular region of axons with nucleus in the center for synapses.
Definition
Tractus Solitarus
Term
Where are the 1st order neurons for the visceral sensory portion of the vagus nerve?
Definition
Converge in plexuses surrounding target organs in the abdomen and thorax and ascend in the thorax as the right and left vagus nerves. Cell bodies are located in the inferior vagal ganglion (swelling of vagus nerve just external to jugular foramen). Processes of these nerves enter the medulla and descend in the tractus solitarius to enter the caudal portion of nucleus of the solitary tract.
Term
Where are the 2nd order neurons located for the visceral sensory portion of the vagus nerve?
Definition
Nucleus of solitary tract in medulla. Neurons from the nucleus solitarius synapse on 3rd order neurons in the dorsal motor nucleus of vagus, reticular formation and hypothalamus for reflexive control of cardiovascular, respiratory and GI functions.
Term
What is the function for the GSA (General Sensory) portion of the vagus nerve?
Definition
General sensation (touch, pain, temp) from skin of external ear, external auditory canal, external surface of tympanic membrane, larynx, pharynx, and meninges of posterior cranial fossa
Term
Where are the 1st order neurons of the general sensory portion of the vagus nerve?
Definition
They travel with the branches of the vagal nerve, and cell bodies are located in the superior vagal ganglion (within the jugular foramen). Processes enter the medulla and descend in the spinal trigeminal tract to synapse in the spinal nucleus of V
Term
Where are the 2nd order neurons located in the general sensory portion of the vagus nerve?
Definition
In the spinal nucleus of V and project their axons via the ventral trigeminothalamic tract to the contralateral VP of thalamus
Term
Where are the 3rd order neurons located in the general sensory portion of the vagus nerve?
Definition
3rd order thalamic neurons project through the internal capsule to sensory cortex of the cerebrum
Term
A huge sensory relay nucleus
Definition
VPL of thalamus
Term
This cranial nerve emerges from the medulla as most rostral of a series of rootlets that emerge between the olive and the inferior cerebellar peduncle.
Definition
Glossopharyngeal
Term
Where does the glossopharyngeal nerve exit the cranial fossa?
Definition
Jugular Foramen
Term
What are the 2 ganglia called that are situated on the glossopharyngeal nerve?
Definition
Superior and Inferior Glossopharyngeal ganglia
Term
Where all does the glossopharyngeal nerve receive innervation from?
Definition
SVE (Branchial Motor), GVE (Visceral Motor), GVA (Visceral Sensory), GSA (General Sensory), and SVA (Special Sensory)
Term
What is the function of the branchial motor component of the glossopharyngeal nerve?
Definition
Motor to the stylopharyngeus muscle to elevate the pharynx during swallowing and speech.
Term
Where are the CBOs for the branchial motor portion of the glossopharyngeal nerve?
Definition
Nucleus Ambiguus - (it contains motor neurons)
Term
Where is the LMN in the branchial portion of the glossopharyngeal nerve?
Definition
Exits medulla as 3-4 rootlets in the groove between the olive and cerebellar peduncle just rostral to CNX. Rootlets converge as the glossopharyngeal nerve and exit thru the jugular foramen. Gives off muscular branch deep to the styloid process to innervate the ipsilateral stylopharyngeus muscle.
Term
Where is the UMN for the branchial motor portion of the glossopharyngeal nerve?
Definition
Located in the primary motor cortex and send axons through the internal capsule and base of peduncles to synapse bilaterally on LMN in the rostral portion of nucleus ambiguus
Term
What is the function of the visceral motor portion of the glossopharyngeal nerve?
Definition
Parasympathetic innervation to the parotid gland. Activation leads to increased secretion from the parotid gland.
Term
Where are the CBOs for the visceral motor portion of the glossopharyngeal nerve?
Definition
Preganglionic parasympathetic neurons are located in the inferior salivatory nucleus. Influence by the hypothalamus (via dorsal longitudinal fasciculus) and olfactory system.
Term
Where are the UMN for the visceral motor portion of the glossopharyngeal nerve?
Definition
Axons from the CBOs join other components of CNIX and travel to inferior glossopharyngeal ganglion in the jugular foramen. Here, they separate from CNIX and travel thru the tympanic cavity. Emerge from the tympanic plexus as the lesser petrosal nerve and exit the cranial cavity to synapse in the otic ganglion
Term
Where is the LMN of the visceral motor portion of the glossopharyngeal nerve?
Definition
Postganglionic parasympathetic neurons are located in the otic ganglion and send axons with the auriculotemporal nerve (V3) to eventually supply secretomotor innervation to parotid gland
Term
Helps regulate blood gases
Definition
Carotid Body
Term
What is the function of the visceral sensory portion of the glossopharyngeal nerve?
Definition
Receive information from chemoreceptors in the carotid body to monitor O2 and CO2 tension in circulating blood and from baroreceptors (stretch receptors) in the carotid sinus - monito arterial BP
Term
Where are the 1st order neurons for the visceral sensory portion of the glossopharyngeal nerve?
Definition
GVA fibers fromt arget regions convey information to cell bodies located in the inferior glossopharyngeal ganglion. From here, central processes enter the medulla and tractus solitarious to synapse in the solitary nucleus
Term
Where are the 2nd order neurons for the visceral sensory portion of the glossopharyngeal nerve?
Definition
Processes project to reticular formation, hypothalamus and dorsal motor nucleus of X for appropriate reflex responses (DMNX - decrease HR and BP)
Term
Where are the CBOs for the visceral sensory portion of the glossopharyngeal nerve?
Definition
Inferior glossopharyngeal ganglion and solitary nucleus of medulla
Term
What is the function of the general sensory portion of the glossopharyngeal nerve?
Definition
Cutaneous sensation to skin posterior to ear and inner surface of tympanic membrane. Also recieves information regarding general sensation from the posterior 1/3 of tongue to entrance to the pharynx
Term
Where are the 1st order neurons for the general sensory portion of the glossopharyngeal nerve?
Definition
GSA fibers from target regions convey information to cell bodies located int he inferior glossopharyngeal ganglion. From here, central processes enter the medulla and descend within the spinal trigeminal tract to synapse in the middle third of the nucleus
Term
Where are the 2nd order neurons in the general sensory portion of the glossopharyngeal nerve?
Definition
Cross midline in the medulla and ascend to contralateral VP nucleus of thalamus
Term
Where are the 3rd order neurons of the general sensory portion of the glossopharyngeal nerve?
Definition
Project to the post-central sensory gyrus
Term
The sensory arm of the gag reflex
Definition
General sensory of glossopharyngeal nerve
Term
Where are the CBOs of the general sensory portion of the glossopharyngeal nerve?
Definition
Inferior glossopharyngeal ganglia and spinal nucleus of V
Term
If you had a lesion of CNIX what would you see?
Definition
No gag reflex
Term
What is the function of the special sensory division of the glossopharyngeal nerve?
Definition
Taste from the posterior 1/3 of the tongue
Term
Where are the 1st order neurons for the special sensory portion of the glossopharyngeal nerve?
Definition
SVA fibers from the posterior 1/3 of the tongue convey information to cell bodies located in the inferior glossopharyngeal ganglion. Central processes pass thru jugular foramen, enter medulla and ascend in tractus solitarius to synapse in the rostral nucleus
Term
Where are the 2nd order neurons for the special sensory portion of the glossopharyngeal nerve?
Definition
Cell bodies in the rostral nucleus solitarius (gustatory). Axons ascend int he central tegmental tract of brainstem to reach the ipsilateral VP nucleus of the thalamus
Term
Where are the 3rd order neurons of the special sensory portion of the glossopharyngeal nerve?
Definition
Ascend from the thalamus thru the posterior limb of the internal capsule to reach primary sensory cortex in the postcentral gyrus
Term
Where are the CBOs for the special sensory portion of the glossopharyngeal nerve?
Definition
Inferior glossopharyngeal ganglion and rostral part of nucleus solitarius - this part of the nucleus is termed the gustatory nucleus
Term
From Medial to Latera, name the motor to sensory nuclei of the cranial nerves.
Definition
GSE, SVE, GVE, GVA/SVA, GSA, and SSA
Term
Name the nucleus for the olfactory nerve.
Definition
Neurosensory cells of the olfactory epithelium
Term
Name the nucleus for the optic nerve
Definition
ganglion cells of retina
Term
Name the nucleus for the oculomotor nerve.
Definition
Oculomotor and Edinger-Westphal
Term
Name the nucleus for the trigeminal nerve.
Definition
Trigeminal (Spinal, Mesencephalic, Principal Sensory) and Motor Nucleus of V
Term
Name the nucleus for the abducens nerve
Definition
Abducens
Term
Name the nucleus for the facial nerve.
Definition
Spinal Trigeminal, Solitarius, Superior Salivatory, Facial
Term
Name the nucleus for the vestibulocochlear nerve.
Definition
Vestibular, Cochlear
Term
Name the nucleus for the Glossopharyngeal nerve?
Definition
Spinal Trigeminal, Solitarius, Ambiguus, Inferior Salivatory
Term
Name the nucleus for the Vagus nerve.
Definition
Spinal Trigeminal, Solitarius, Ambiguus, Dorsal motor nucleus of vagus
Term
Name the nucleus for the hypoglossal nerve
Definition
Hypoglossal
Term
Name the nucleus for the accessory nerve
Definition
Accessory
Term
What is the function of the neurosensory cells of the olfactory epithelium for the olfactory nerve?
Definition
Sense of smell
Term
What is the function of the ganglon cells of the retina for the optic nerve
Definition
Vision
Term
What is the function of the oculomotor nuclei in the oculomotor nerve?
Definition
Motor to levator palpebrae superioris and all extraocular eye muscles except sup. oblique, and lateral rectus
Term
What is the function of the Edinger-Westphal nucleus of the oculomotor nerve?
Definition
Parasympathetic supply to ciliary muscle, constrictor pupillae
Term
What is the function of the Spinal, Mesencephalic, and Principal sensory trigeminal nuclei for the trigeminal nerve?
Definition
Sensory from surface of head and neck, sinuses, meninges, and tympanic membrane (external surface)
Term
What is the function of motor nucleus of V for the trigeminal nerve?
Definition
Muscles of mastication
Term
What is the function of the abducens nuclei of the abducens nerve?
Definition
Motor to lateral rectus muscle
Term
What is the function of the spinal trigeminal nucleus of the facial nerve?
Definition
General sensation from part of the external ear, external surface of tympanic membrane
Term
What is the function of the Solitarius nucleus of the facial nerve?
Definition
Taste for the anterior 2/3 of the tongue and mucosa
Term
What is the function of the Superior Salivatory nucleus of the facial nerve?
Definition
Parasympathetic supply to lacrimal, submandibular, and sublingual glands
Term
What is the function of the facial nucleus for the facial nerve?
Definition
Motor to muscles of facial expression
Term
What is the function of the vestibular nucleus of the vestibulocochlear nerve?
Definition
Balance
Term
What is the function of the cochlear nucleus of the vestibulocochlear nerve?
Definition
Hearing
Term
What is the function of the spinal trigeminal nucleus of the glossopharyngeal nerve?
Definition
General sensation from posterior 1/3 of tongue and internal surface of the tympanic membrane
Term
What is the function of the solitarius nucleus of the glossopharyngeal nerve?
Definition
Visceral sensory from the carotid body and sinus. Taste for posterior 1/3 of tongue
Term
What is the function of the ambiguus nucleus of the glossopharyngeal nerve?
Definition
Motor to stylopharyngeus muscle
Term
What is the funcon of the inferior salivatory nucleus of the glossopharyngeal nerve?
Definition
Parasympathetic to parotid gland
Term
What is the function of the spinal trigeminal nucleus of the vagus nerve?
Definition
General sensation from part of external ear
Term
What is the function of the solitarius nucleus of the vagus nerve?
Definition
Visceral sensory from pharynx, larynx, viscera, and aorta
Term
What is the ambiguus nucleus of the vagus nerve?
Definition
Motor to muscles of the pharynx and larynx
Term
What is the function of the dorsal motor nucleus of the vagus?
Definition
Parasympathetic supply to thoracic and abdominal viscera
Term
Wat is the function of the accessory nucleus of the accessory nerve?
Definition
Motor to SCM and traps
Term
What is the function of the hypoglossal nucleus of the hypoglossal nerve?
Definition
Motor to intrinsic and extrinsic muscles of tongue (except palatoglossus)
Term
Name the innervations for the facial nerve.
Definition
SVE (Branchial Motor), GVE (Visceral Motor), GSA (General Sensory), SVA (Special Sensory)
Term
What is the function of the branchial motor portion of the facial nerve?
Definition
motor to muscles of facial expression, stapedius, stylohyoid, and posterior belly of the digastric
Term
Where are the CBOs of the branchial motor portion of the facial nerve?
Definition
LMN are located in the motor nucleus of CNVII in the pontine tegmentum
Term
Fibers ascend dorsomedially toward the floor of the 4th ventricle, hook around abducens nucleus (internal genu of CNVII) and exit from the brainstem on its ventral surface near the caudal border of the pons, at the cerebellopontine angle. Exits the cranial cavity via the internal auditory meatus, travels thru the facial canal, and exits via the stylomastoid foramen
Definition
Branchial Motor portion of the Facial Nerve
Term
Where are the UMN for the branchial motor portion of the facial nerve?
Definition
Corticobulbar fibers from the motor cortex project bilaterally to muscles of the forehead and contralaterally to muscles of the lower face
Term
What would present with a patient with an UMNL in the branchial motor portion of the facial nerve?
Definition
Involves corticobulbar fibers to facial nucleus - loss of voluntary control of lower muscles of facial expression contralateral to lesion; muscles of the forehead remain intact due to bilateral innervation by the corticobulbar fibers
Term
What would a LMNL look like in the branchial motor portion of the facial nerve?
Definition
Facial nucleus or nerve - loss of voluntary control of all muscles of facial expression (upper and lower) ipsilateral to lesion. Most common is injury to nerve - Bell's Palsy
Term
This is the component to the motor arm of the corneal reflex. Motor to orbicularis oculi muscle, touch cornea with cotton and the patient blinks, sensory arm is CNV
Definition
Branchial motor portion of the facial nerve
Term
What is the function of the visceral motor portion of the facial nerve?
Definition
Parasympathetic innervation of lacrimal gland, submandibular and sublingual glands
Term
Where are the CBOs of the visceral motor portion of the facial nerve?
Definition
Superior salivatory nucleus - these are preganglionic parasympathetic neurons. They are influenced primarily by the hypothalamus via the dorsal longitudinal fasciculus
Term
Efferent fibers travels in nervus intermedius - smaller component of the facial nerve and divide into 2 nerves at the genticulate ganglion: Greater Petrosal and Chorda Tympani
Definition
Visceral Motor portion of Facial Nerve
Term
Fibers synapse in the pterygopalatine ganglion. Postganglionic parasympathetic fibers travel with fibers of other CNs to supply the lacrimal and nasal glands
Definition
Greater Petrosal Nerve
Term
Fibers travel and join the lingual nerve and synapse in the submandibular ganglion. Postglanglionic parasympathetics are sent to the submandibular and sublingual glands
Definition
Chorda Tympani Nerve
Term
What is the function of the general sensory portion of the facial nerve?
Definition
General sensation (touch, pain, temp, etc) from external auditory meatus and skin posterior to ear. Fibers from these regions join the branchial motor axons at hte stylomastoid foramen and travel centrally
Term
Where are the CBOs of the general sensory portion of the facial nerve?
Definition
1st order neurons are located in the genticulate ganglion, send processes to the spinal nucleus of V. 2nd order axons are projected to the contralateral VP nucleus of the thalamus and 3rd order projections to the sensory cortex
Term
What is the function of the special sensory portion of the facial nerve?
Definition
Tast from the anterior 2/3 of the tongue
Term
Where are the CBOs of the special sensory portion of the facial nerve?
Definition
Sensory fibers from the taste buds travel with chorda tympani to their 1st order cell bodies located int he geniculate ganglion and synapse in the rostral part of hte solitary nucleus (gustatory nucleus)
Term
What are the 3 major division of the Trigeminal nerve?
Definition
Ophthalamic, Maxillary, and Mandibular
Term
What is the trigeminal nerve innervated by?
Definition
SVE (Branchial Motor) and GSA (General Sensory)
Term
What is the function of the branchial motor portion of the trigeminal nerve?
Definition
Motor to muscles of mastication, tensor tympani, tensor (velli) palatini, mylohyoid and anterior belly of digastric
Term
Where are the CBOs of the branchial motor portion of the trigeminal nerve?
Definition
Motor nucleus of trigeminal nerve in pons
Term
Where are the LMN of the branchial motor portion of the trigeminal nerve?
Definition
Axons from the masticator nucleus (motor nucleus of V) exit the pons as the motor root on the medial aspect of the sensory root on V3. Axons course thru the trigeminal nucleus, exit the cranium, and give motor branches
Term
Where are the UMN for the branchial motor portion of the Trigeminal nerve?
Definition
Bilateral innervation from the corticobulbar fibers, which send axons thru internal capsule to motor nucleus of trigeminal
Term
What would an UMNL of the branchial motor portion of the trigeminal look like?
Definition
Minimal symptoms due to bilateral corticobulbar innervation
Term
What would a LMNL look like in the branchial motor portion of the trigeminal nerve?
Definition
If motor nucleus of V, ipsilateral paralysis of muscles of mastication. If entire nerve, see sensory loss in face as well - GSA component
Term
What is the function of the general sensory portion of the trigeminal nerve?
Definition
Sensation from face and scalp, conjunctiva, mucous membranes of nasal and oral cavities including teeth, anterior 2/3 of tongue and part of external aspect of tympanic membrane
Term
Where are the CBOs of the general sensory portion of the trigeminal nerve?
Definition
Most of the 1st order sensory cell bodies reside in the trigeminal ganglion. Central processes enter the pons and synapse with the 2nd order neuron in the appropriate region of the trigeminal nucleus. Trigeminal nucleus is the largest CN nucleus and extends from midbrain to spinal cord as far as C2. Here, it becomes continuous with the dorsal horn of the spinal cord
Term
Receives pain and temperature sense from areas innervated by CNV. Axons of 2nd order neurons cross the midline and join the spinal lemniscus to travel to intralaminar and VP nuclei of the thalamus. 3rd order neurons project to sensory cortex
Definition
Spinal nucleus of V
Term
Tactile, pressure, and discriminative touch sensation from areas innervated by CNV. Axons cross the midline and join the medial lemniscus to travel to the VP nucleus of the thalamus. 3rd order thalamic neurons travel through internal capsule to the primary sensory cortex.
Definition
Principle Sensory Nucleus of V
Term
Pressure and kinesthesia from teeth, periodontium, hard palate, and joint capsules; proprioception from muscles of mastication. Central processes project primarily to the motor nucleus of V to provide reflex control of bite - concerned with mechanisms that control the force of the bite.
Definition
Mesencephalic Nucleus
Term
The componenet of the sensory arm of the corneal reflex
Definition
General sensory portion of trigeminal nerve
Term
Tap the patients chin - reflex contractions of masseter and temporalis muscles. Sensory arm is GSA component (mesencephalic nucleus) and the motor arm is the SVE component (motor nucleus of V)
Definition
Jaw Jerk Reflex
Term
What is the innervation of the abducens nerve?
Definition
Somatic MOtor
Term
What is the function of the abducens nerve?
Definition
innervates the lateral rectus
Term
What are the CBOs of the abducens nerve?
Definition
Abducens Nucleus - floor of 4th ventricle in pons, near the midline. Motor neurons and interneurons
Term
What nerve loops around the abducens nucleus in the facial genu to exit the pons?
Definition
Facial nerve
Term
Where are the LMN o the abducens nerve?
Definition
Axons emerge from the medial aspect of the abducens nucleus, pass ventrally thru pontine tegmentum, exit brainstem at caudal border of pons, lateral to corticospinal tract
Term
Interneurons of the abducens nerve
Definition
Send fribers to contralateral side of brain stem. These fibers ascend in contralateral MLF to innervate part of contralateral oculomotor nucleus, which innervates medial rectus of the opposite eye. One way which both eyes move together to produce conjugate gaze
Term
A fiber tract that interconnects the abducens, trochlear, and oculomotor nuclei. This allows for coordinated and simultaneous movement of both eyes.
Definition
Interneurons of abducens nerve
Term
What is the most frequently lesioned cranial nerve?
Definition
Abducens
Term
What occurs if you lesion the abducens nerve?
Definition
Paralysis of the ipsilateral lateral rectus - medial Strabismus
Term
Unopposed medial rectus muscle
Definition
Medial Strabismus
Term
What occurs when there is a lesion to the abducens nucleus?
Definition
Paralysis of lateral gaze to side of lesion. Lateral Gaze Paralysis
Term
Due to loss of neurons innervating ipsilateral lateral rectus and significant portion of neurons innervating contralateral medial rectus. Can also occur with damage to MLF
Definition
Lateral Gaze Paralysis
Term
The only nerve whose cell bodies originate from the contralateral nucleus
Definition
Trochlear
Term
The only cranial nerve to emerge on the dorsal surface of the brainstem, just caudal to the inferior colliculus
Definition
Trochlear
Term
What is the function of the trochlear nerve?
Definition
innervate superior oblique which turns eyes down and out and medially rotates the eyeball
Term
CBOs of the trochlear nerve?
Definition
trochlear nucleus - ventral border of PAG in midbrain - motor neurons
Term
LMN of trochlear nerve?
Definition
Crosses immediately to contralateral side in superior medullary velum - exits dorsal surface of brainstem caudal to inferior colliculus, then curves around brainstem to reach ventral surface
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