Exam 1: Unit III: CN V; Trigeminal Nerve Flashcards
What CN is known as the “Great Sensory Nerve of the Face”?
Trigeminal N (CN V)
What is the largest CN?
Trigeminal N (CN V)
What type of fibers does the Trigeminal N carry?
Mixed nerve; carries mostly (general) sensory fibers, but also carries motor fibers
What are the three nuclei of termination associated with the Trigeminal Nerve?
- Main sensory nucleus
- Spinal Nucleus
- Trigeminal mesencephalic nucleus
How many nuclei of origin does the Trigeminal have?
One; called Trigeminal motor nucleus
What is the peripheral ganglion ass. with the Trigeminal Nerve called? What type of cell bodies does it contain?
Trigeminal (semilunar) ganglion; contains cell bodies of 1st order sensory neurons
(similar to DRG of a spinal N)
The Trigeminal gets its name from what?
Its three peripheral branches:
- Ophthalmic (V1)
- Maxillary (V2)
- Mandibular (V3)
Where do the three peripheral branches of the Trigeminal Nerve come off?
come off Trigeminal Ganglion, located in PNS (NOT off CNS)
Where do the sensory pathways of the Trigeminal Nerve go?
to the nuclei of termination (main, spinal, mesencephalic)
Where are the cell bodies of the main sensory nucleus and spinal nucleus of the Trigeminal nerve located?
cell bodies located in trigeminal ganglion
For the sensory pathway of the trigeminal nerve, the _______ processes come from the ______ to the ______ ______. Then the _____ processes from there enter the CNS and go to either main or spinal nuclei.
peripheral processes; face to the trigeminal ganglion; central processes (axons)
What type of sensory information is carried to the main trigeminal nucleus?
touch, vibration, joint proprioception (TMJ)
What type of sensory information is carried to the spinal nucleus of the trigeminal nerve?
pain and temperature
What are the cord pathways that would be analogous to info carried to the spinal nucleus of trigeminal nerve?
lateral spinothalamic tract carries pain and temp
(3 neuron pathway)
- 1st neuron enter cord and cross immediately
- 2nd neuron ascends up cord and synapses in thalamus
- 3 neuron goes from thalamus to cerebral cortex
What are the cord pathways that would be analogous to info carried to the main trigeminal nucleus?
Gracilis and Cuneatus carry —–
Anterior spinothalamic tract carries —
???????
What is unique about the neurons going to the trigeminal mesencephalic nucleus?
dendrites from periphery pass THROUGH the trigeminal ganglion, enter CNS, and ascend to nucleus
–there are the ONLY primary sensory neurons that have cell bodies located in the CNS
What type of information is carried to the trigeminal mesencephalic nucleus?
proprioception info form muscles of mastication
What type of neurons are in the motor pathway for the trigmeinal nerve?
since going out into PNS, but be LMNs
What is the only branch of the trigeminal nerve that carries motor fibers?
mandibular branch
Describe the pathway of the axons leaving the motor nucleus of the trigeminal nerve.
Axons from motor nucleus leave CNS and travel THROUGH trigeminal ganglion to be carried in the mandibular branch to supply 8 muscles
What 6 areas does the motor nucleus of the trigeminal nerve receive information from?
- cerebral cortex (both hemispheres)
- reticular formation
- red nucleus
- tectum
- medial longitudinal fasciculus (MLF)
- mesencephalic nucleus (monosynaptic reflex)
Where is the apparent origin of the trigeminal nerve?
lateral aspect of pons
The trigeminal nerve travels _________ over the _____ ___ of the ____ bone, and enters a pouch of dura called the ____ ____.
anteriorward; petrous part of the temporal bone; trigeminal (Meckel’s) cave.
Where is the trigeminal ganglion found?
in a pouch of dura called the trigeminal (Meckel’s) cave
After passing through the trigeminal cave (where trigeminal ganglion is found) the trigeminal nerve moves further into the periphery and then what?
three banches/divisions arise (Ophthalmic, maxillary, mandibular)
What structure does the ophthalmic division enter the orbit through?
superior orbital fissure (same as III, IV, VI)
What type of function does the ophthalmic division (V1) have?
sensory function ONLY
Where does the ophthalmic division (V1) carries sensational information from?
- skin over nose, forehead, and scalp
- mucous membranes in frontal and sphenoid sinuses
- membranes covering nasal septum
What are the 4 branches that the ophthalmic division (V1) gives rise to?
- meningeal nerve, or tentorial branch
- lacrimal nerve
- Frontal nerve
- Nasociliary nerve
(2-4 = the three main ones)
When is the meningeal nerve (or tentorial branch) of the V1 given off? What does it supply?
give off BEFORE opthalmic division leaves the superior orbital fissure
- supplies dura mater lining middle cranial fossa
Which is the smallest of the three main branches of the Ophthalmic nerve?
lacrimal nerve
Describe the path the lacrimal branch of V1 takes.
- travels along superior aspect of lateral rectus
- passes THROUGH lacrimal gland (and supplies it)
- and reaches the skin of the upper eyelid
The lacrimal nerve of V1 carries ______ ______ fibers to the lacrimal gland. These fibers originate in the _______ _____. These fibers reach the lacrimal nerve via the ________ nerve.
postganglionic parasympathetic (secretory) fibers
pterygopalatine ganglion (CN VII)
zygomatic nerve (CN V2)
List in order the path of how the postganglionic parasympathetic fibers reach the lacrimal gland.
- Pterygopalatine ganglion (CN VII)
- zygomatic nerve (V2)
- lacrimal nerve
- lacrimal gland
Which is the largest branch of the ophthalmic division (V1) out of the three main branches?
Frontal nerve
How many branches does the Frontal Nerve (branch of V1) branch into? What are they?
- Supratrochlear nerve
2. Supraorbital nerve
What area does the Supratrochlear nerve (branch of Frontal Nerve of V1) convey sensation from?
medial corner of the eye
What area does the Supraorbital nerve (branch of Frontal Nerve of V1) convey sensation from?
- conjunctiva
- upper eyelid
- forehead
- mucous membrane lining frontal sinus
Which of the main branches of the ophthalmic nerve (V1) gives off the most branches? How many?
Nasociliary nerve
- 3 branches before dividing into 2 terminal branches
(5 total branches)
What are the 3 branches the Nasociliary nerve (branch of V1) give off? What are the 2 terminal branches?
- communicating branch
- long ciliary nerve
- posterior ethmoid nerve
Terminal:
- Anterior ethmoid nerve
- Infratrochlear nerve
Where does the communicating branch of the nasociliary nerve (branch of V1) go to?
ciliary ganglion (corneal reflex)
What does the long ciliary nerve, branch of the nasociliary nerve (branch of V1), supply?
supplies the eyeball
What does the Posterior ethmoid nerve, branch of nasociliary nerve (branch of V1), carry sensory info from?
from sphenoidal and ethmoidal sinuses
What are the two terminal branches of the nasociliary nerve?
Anterior ethmoid nerve
Infratrochlear nerve
What does the anterior ethmoid nerve supply sensory info from? (branch of nasociliary nerve, branch of V1)
External nasal nerve — skin over the nose
Internal nasal nerve – mucous membrane covering anterior part of the nasal septum
What does the Infratrochlear nerve supply sensory info from? (branch of nasociliary nerve, branch of V1)
medial corner of the eye, including the lacrimal sac
What kind of nerve fibers does the maxillary division (V2) carry? And what does it supply?
sensory only
- skin b/w eyes and mouth,
- over cheeks and temples,
- mucosa lining maxillary sinuses, nasal conchae, palate, and gingiva (of maxialla)
Where does the Maxillary division enter and vie what structure?
enters the pterygopalatine fossa through the foramen rotundum (round foramen)
How many branches does the Maxillary Division have of the Trigeminal nerve? What are they?
Four:
- Middle meningeal nerve
- Zygomatic Nerve
- Ganglionic Branches (2-3)
- Infraorbital nerve
When does the middle meningeal nerve branch off of Maxillary division? What does it supply?
before the division exits the foramen rotundum (round foramen)
supplies the meninges of the middle cranial fossa
How many branches come off the zygomatic branch of the maxillary division?
Three:
- Communicating branch
- Zygomaticotemporal nerve
- Zygomaticofacial nerve
What does the zygomatic nerve go through to enter the orbit?
the inferior orbital fissure
What type of fibers does the communicating branch of the zygomatic nerve of V2 carry?
postganglionic parasympathetic fibers from the pterygopalatine ganglion to the lacrimal gland
What does the zygomaticotemporal nerve supply sensory info from?
(branch of zygomatic nerve of V2)
skin over the temple
What does the zygomaticofacial nerve supply sensory info from?
(branch of zygomatic nerve of V2)
skin over the cheek
Where do the ganglionic branches of the maxillary division carry sensory information from? How does it get to the maxillary division?
upper pharynx, nasal cavity, and palate THROUGH the pterygopalatine ganglion to the maxillary division
What does the infraorbital nerve travel through to enter/leave the orbit?
through the inferior orbital fissure (infraorbital fissure) and infraorbital canal
What branches does the infraorbital nerve have and when are they given off?
give off before entering the infraorbital canal, they are:
Posterior superior alveolar nerve
Middle superior alveolar nerve
Anterior superior alveolar nerve
What sensory info do the superior alveolar nerves carry? (branch of infraorbital nerve, of V2)
Overall: sensory info from teeth of maxilla
Posterior — from molars
Middle – from premolars (canines too)
Anterior– from incisors (canines too)
What sensory information does the infraorbital nerve carry info from?
- lower eyelid
- skin over upper jaw
- maxillary sinus
- teeth of maxilla (from its P,M,A superior alveolar branches)
What do the posterior, middle, and anterior superior alveolar branches form that is just above the alveoli?
superior dental plexus
Branches of the maxillary division of the trigeminal nerve (sensory) are used to distribute what type of fibers from the pterygopalatine ganglion?
postganglionic parasympathetic fibers (communicating branch of the zygomatic nerve of V2)
How do preganglionic parasympathetic fibers reach the pterygopalatine ganglion from the facial nerve?
via the greater petrosal nerve
What type of fibers from the superior cervical ganglion pass THROUGH the pterygopalatine ganglion?
postganglionic sympathetic fibers
How does the mandibular division exit the cranial vault?
via the foramen ovale (oval foramen)
What type of fibers does the mandibular division of the trigeminal nerve carry?
sensory and motor
A ______ sensory root and a ____ motor root combine in the ______ ____ to form the mandibular division after exiting the foramen ovale.
large sensory root, and small motor root; combine in the infratemporal fossa
What structures does the mandibular division carry sensory information from?
- skin over the mandible, posterior cheek, posterior temple
- mucosa of the lower oral cavity and cheeks
What motor innervation does the mandibular division carry?
8 muscles, including muscle of mastication:
- masseter
- medial pterygoid
- lateral pterygoid
- temporalis
Where are the Recurrent meningeal branch (nervus spinosum) and the medial pterygoid nerve given off from the mandibular division?
in the infratemporal fossa
What two branches of the mandibular division are given off in the infratemporal fossa?
- recurrent meningeal branch (nervus spinosum)
- medial pterygoid nerve
What is the route of the recurrent meningeal branch of V3 and what information does it carry?
given off in the infratemporal fossa –> reenters the cranium via the foramen spinosum
- carries sensory information from dura of middle cranial fossa, anterior cranial fossa, and calvarium (supratentorial dura)
What does the medial pterygoid nerve (branch of V3) supply?
motor–
- for medial pterygoid muscle
- some fibers pass THROUGH otic ganglion and supply tensor veli palatine and tensor tympani
After the mandibular division gave off its two branches in the infratemporal fossa, what does the nerve do?
it divides into predominantly motor anterior division and a predominantly sensory posterior division
What does the Anterior division of the mandibular division give rise to? (4)
- Masseter nerve (M,S)
- Deep temporal nerve (M)
- Lateral pterygoid nerve (M)
- Buccal nerve (S)
What does the masseter nerve supply?
- motor innervation to masseter
- sensory info from TMJ
What are the branches of the deep temporal nerve and what do they supply?
anterior and posterior branch; supply temporalis muscle
What does the lateral pterygoid nerve supply?
(branch of Anterior division of V3)
- supplies lateral pterygoid muscle
What is the major sensory branch of the anterior division of the mandibular division? What does it supply?
Buccal Nerve: supplies:
- cheek (both skin and mucosal surface)
- buccal gingivae of molars
What branches does the Posterior division of the mandibular nerve give rise to?
(mostly sensory)
- Auriculotemporal nerve (S)
- Lingual nerve (S)
- Inferior alveolar nerve (S and M)
Is the anterior or posterior division of the mandibular nerve larger?
posterior division is larger
What type of fibers does the auriculotemporal nerve carry and what does it supply?
(V3 branch)
sensory info from skin of temple and ear
also carriers postganglionic parasympathetic fibers from the otic ganglion
What is the path the auriculotemporal nerve takes?
passes THROUGH parotid gland, posterior to TMJ, and into the infratemporal fossa
(V3) branch
What sensory info does the lingual nerve carry and what branch does it combine with and where does that occur?
carries sensory info from mucosa of oral cavity
combines with chorda tympani branch of CN VII
in infratemporal fossa
(V3 branch)
What type of info does the inferior alveolar nerve carry? Does it have any branches, if so what?
carries info from lower teeth and chin Two branches: - Incisive branch - Mental Nerve (motor nerves come off too)
(V3 branch)
What does the incisive branch of the inferior alveolar nerve of V3 supply?
incisors, canines, and 1st premolars and adjacent gingiae (of mandible)
What does the mental nerve (branch inferior alveolar nerve of V3) supply?
labial gingivae adjacent to incisors and the skin of lower lip and chin
When do the motor branches of the inferior alveolar nerve diverge from it? What does it supply?
prior to it passing through mandibular foramen; supplies mylohyoid and anterior belly of digastric muscle
What are the four ganglion associated with the trigeminal nerve?
- ciliary ganglion
- pterygopalatine ganglion
- otic ganglion
- submandibular ganglion
What are the two autonomic ganglion that communicate with the mandibular division of trigeminal?
- submanidbular ganglion
2. otic ganglion
The otic ganglion sends ____ ____ fibers to the ____ _____ by the way of the ______ _____.
postganglionic parasympathetic; parotid gland; via auriculotemporal nerve
The submandibular ganglion receives some preganglionic parasympathetic fibers from CN ____ by the way of the ____ ____, (branch of V3) after it combines with the ____ _____.
preganglionic fibers; CN VII; lingual nerve; chorda tympani
If someone comes into your office with the worst pain imaginable covering one side of their face, what are you thinking? Can you help them?
Trigeminal Neuralgia (Tic doloreoux) - no, it just needs to run its course
What dental considerations come to mind when talking about the Trigeminal nerve?
If teeth on mandible need to be worked on, the whole side will be numb due to only one inferior alveolar nerve
The dentist will be able to pinpoint better for the teeth of the maxilla (b/c Ant, Middle, and Post. superior alveolar nerves)
