Gross Anatomy of the Trigeminal Nerve Flashcards
Trigeminal Nerve portions
V1 - Opthalmic nerve
V2 - Maxillary Nerve
V3 - Mandibular Nerve
CN-V emerges from the brain-stem as?
a large sensory GSA and a small motor SVE root
resident fobers of Cn-V
GSA and SVE
GSA
General somatic afferent
- general sensations from the face like pain, temperature, touch, proprioception
SVE
special visceral efferent
muscles of the first pharyngeal arch
acquired fibers of CN-V
SA -special afferent (taste)
GVE - general visceral efferent - like parasympathetic fibers to smooth muscles - constrictor of the pupil and glands - submandibular gland
Where does CN-V emerge
into the posterior cranial fossa –> courses anteriorly to reach the middle cranial fossa
If the trigeminal ganglion is a sensory ganglion - what cells are in it?
pseudounipolar neurons
where is the trigeminal ganglion located?
in the trigeminal impression/trigeminal cave or meckel’s cave
what emerges from the trigemnial ganglion?
V1 V2 and V3
course of V1 and V2
pass in the lateral wall of the cavernous sinus to reach the superior orbital fissure –> into orbit and the foramen rotundum –> pterygopalatine fossa, respectively
course of V3
takes a more anterior course –> to the foramen ovale –> infratemporal fossa
branches off of the opthlamic nerve (v1)
Meningeal branch
Lacrimal nerve
Frontal nerve (Suprs orbital and supra trochlear nerve)
Nasociliary nerve - a lot of branches
meningeal branch (tentorial nerve)
sensory branch that emerges from V1 BEFORE it traverses the superior orbital fissure
this is smaller nerve and passing back more posterior
Lacrimal nerve
branch from V1
travels along the lateral border of the orbit to reach the lacrimal gland and lateral eye
frontal nerve and branches
from V1
within the orbit, the frontal nerve branches into the supraorbital and supratrochlear nerves
- both of these branches will course anteriorly through the orbit and emerge superior to the eye along with same named arteries
Nasociliary nerve
origin and course
from v1 - opthalmic nerve
travels deep/inferior to the lacrimal and frontal nerves
branches of the nasociliary nerve
Sensory root --> CILIARY GANGLION--> short ciliary nerves long ciliary nerves Posterior ethmoidal nerve Anterior ethmoidal nerve Infratrochlear nerve
where is the location of the trigenminal ganglion?
middle temporal fossa
what fibers do the ciliary ganglion receive? general
sensory root
parasympathetic root
sympathetic root
where do the preganglionic parasympathetic fibers that reach the ciliary ganglion come from - be specific
these are PREGNAGLIONIC FIBERS that originate in the Edinger-Westphal nucleus. These fibers travel with CN III to the ciliary ganglion and WITHIN THE CG THEY SNAPASE W? PARASYMPATHETIC GANGLION CELLS
now the ganglion is where we have post ganglionic cell bodies (pre synapsing)
postganglionic parasympathetic fibers of the Ciliary ganlgion
these leave the CG via SHORT CILIARY NERVES and enter the globe and provide innervation to the constrictor of the pupil and ciliary muscle
what synapses and does not synapse in ciliary ganglion
sensory (GSA) from V1 and POSTGANGLIONIC sympathetic (GVE) do NOT synapse – parasympathetic fibers from EDW (from CN III) synapse here
Branches of the maxillary nerve (v2) prior to traversing the foramen rotundum
Meningeal branch - nervous meningeus medius
Branches of V2 in the prerygopalatine fossa (PPF)
Zygomatic nerve and branches
Communicating branch (2) with pterygopalatine ganglion (more to this
Posterior superior alveolar nerve
Infraorbital nerve - CONTINUATION OF THE MAXILLARY NERVE - plus its branches
Zygomatic Nerve
enters the orbit via the inferior orbital fissure and gives rise to the zygomaticofacial and zygomaticotemporal nerves which then leave the orbit through the same named formamen
what does the zygomaticotemporal nerve do?
gives off COMMUNICATING BRANCH to the lacrimal nerve of V1 - so we now have communication between V1 and V2
Communicating roots to PPG
aka pterygopalatine nerves
suspend the PPG in the PPF
primary GSA fibers
THESE PASS THROUGH THE PPG WITHOUT INTERRUPTION (NO SYNAPSE) and give off many branches
GSA fibers pass through PPG without interruption and the communicating roots to PPG give off what nerves
orbital branches Nasopalatine nerve medial posterior superior nasal nerve lateral posterior superior nasal nerve greater palatine nerve lesser palatine nerve pharyngeal nerve
group to orbit
3 to the nasal cavity
2 to palatine
1 to pharynx (nasopharynx)
orbital branches from PPG
traverse the inferior orbital fissure to reach the orbit
nerves from PPG that go to the nasal cavity
names and what they go through
Nasopalatine
medial posterior superior nasal
lateral posterior superior nasal
go through the sphenopalatine foramen to enter the nasal cavity
pharyngeal nerve
off of the PPG and descend through the palatovaginal canal to reach the nasopharynx
nerves from the PPG that go to the palate
Greater and lesser palatine nerves
go through the palatine(greater) canal to reach the hard and soft palate
pterygoid canal and contribution
NERVE of the PTERYGOID CANAL - which includes GVE and SA fibers from CN VII will course through the pterygoid canal (housing this nerve) to reach the PPG
CNVII contributing fibers to the PPG via this canal and nerve
posterior superior aveolar nerve
from the maxillary nerve just before it enters the inferior orbital fissure
- this leaves teh PPF through the pterygomaxillary fissure and enters the maxilla via the alveolar foramen/foramina
infraorbital nerve
CONTINUATION OF THE MAXILLARY NERVE -name change once it enters the orbit
nerve then courses through the infraorbital groove and canal before emerging on the face via the infraorbital foramen
branches from the infraorbital nerve
middle superior alveolar nerve
anterior superior alveolar nerve
supplying maxillary teeth (with the posterior superior alveolar nerve from the maxillary nerve)
how does the infraorbital nerve terminate? What are their distributions
as palpebral–> skin of lower eyelid, nasal–>lateral nose, anterior or nasal septum, and labial branches–> skin of cheeck and upper lip, labial mucosa, and labial/vestibular gingival tissue
superior dental plexus
formed by the nerves that carry sensory information from the MAXILLARY TEETH AND ADJACENT GINGIVAL TISSUE
posterior superior alveolar nerve (from maxillary nerve)
middle superior alveolar nerve
anterior superior alveolar nerve
middle and anterior are from the infraorbital nerve
middle superior alveolar nerve
part of the superior dental plexus
- this is inconsistent and if absent the area this supplies will be filled in either by the anterior superior alveolar nerve or the posterior superior alveolar nerve
innervation of the tooth via the dental plexus
dental pulp is innervated by A-delta and C fibers from CN V (GSA) as well as postganglionic sympathetic fibers from the superior cervical ganglion (GVE)
A delta fibers and C-fibers in dental tooth plexus
enter the root canal along with blood vessels and ramify a plexus
NERVE FIBERS MAY CONTINUE INTO THE ODONTOBLAST LAYER, AND ENTER THE DENTINAL TUBULES - one of the theories of pain as nerves can continue into the dentinal tubule and direct stimulation can cause pain
Theories of pain in the teeth
- DIRECT stimulation of nerve fibers in the dentin
- Odontoblasts as a mediator between the stimuli and the nerve fibers
- Hydrodynamic theory - fluid movement causes the pain in a closed area
clinical correlation with a posterior superior alveolar nerve block
close to the orbit
could have some paralysis to nerves that supply the eye/orbit
double vision
temporary blindness if reach fibers of CN II
Distribution of the posterior superior alveolar nerve
supplies the maxillary molars
EXCEPT THE MESIAL BUCCAL ROOTS
DISTRIBUTION of the middle superior alveolar nerve
mesial buccal roots of the first maxillary molar and the pre molars
maxillary sinus
distribution of the anterior superior alveolar nerve
the incisors and canines
- each also doing the buccal gingival tissue adjacent maxillary sinus
anterior also does the labial gingival tissue, lower lateral nasal wall and floor
distribution of the nasopalatine nerve
portion of the nasal septum, anterior hard palate and adjacent lingual gingival tissue of the maxillary incisors and canines
how does the lacrimal gland get parasympathetic innervation?
synapse in the PPG (ganglion) from the greater petrosal nerve –> nerve of the pterygoid palatine canal from CN VII and synapse here – then have post ganglionic fibers leaving the ganglion - distributed GVE fibers nowwithin V2 branches
GVE parasympathetic fibers of maxillary nerve distribution
maxillary sinus, nasal, palatine glands via the branches of V2
acquired GVE sympathetic fibers of V2
origin and distribution
Deep petrosal Nerve–> Nerve of the pterygoid canal –> and distibuted fibers to maxillary sinus, nasal, paltine glands via branches of V2
-cell bodies in the superior cervical ganglion
where is the cell body of the postganglionic sympathetic fibers
in the superior cervical ganglion
thus there is NO synapse in the PPG of these fibers - pass uninterupted to their respective V2 branches
SA fibers acquired in V2
origin and distribution
from nerve of the pterygoid canal in the pterygoid canal from CN VII and pass into the lesser palatine nerve - going to taste in soft palate
NO SYNAPSE IN THE GANGLION
zygomaticotemporal distribution
skin of the temporal area
zygomaticofacial distribution
skin over the zygomatic arch
orbital branches distribution
sphenoid sinus, post ethmoidal air cells, orbital periosteum
greater palatine distribution
hard palate and adjacent lingual gingival tissue - adjacent the maxillary pre molars and molars
summary of innervation of gingiva and tooth pulp
look at notes and picture drawn
know the gingiva and teeth
Immediate Branches of V3 - mandibular nerve
Meningeal branch (nervus spinosus) Nerve to the medial pterygoid
Nerve to the medial pterygoid distribution
Carries motor (SVE) and proprioceptive fibers (GSA) motor to medial pterygoid muscle, tensor veli palatini muscle, and tensor tympani muscle
Nervous spinosus
a recurrent meningeal branch which re-enters the cranial cavity via the foramen spinosum (travels with the middle meningeal artery) and carries GSA from the meninges of the anterior and middle cranial fossae
anterior division branches of V3
nerve to the lateral pterygoid
deep temporal nerves 2 (anterior and posterior)
masseteric nerve
Long buccal nerve (buccal nerve of V3)
Posterior Division of V3
Auricolotemporal nerve
Lingual nerve
Inferior alveolar nerve
location of the otic ganglion
infratemporal fossa
location of the submandibular ganglion
floor of oral cavity
lingual nerve of posterior division
receives chorda tympani (VII) and has communicating fibers with the submandibular ganglion
inferior alveolar nerve branches
nerve to mylohyoid
terminates as the mental nerve and incisive nerve
space medial to the mandible
infratemporal fossa
T/F the long buccal nerve does not supply the buccinator muscle
TRUE - it pierces it but it is not supplying it - it supplies the buccal mucosa and the gingival tissue adjacent to mandibular molars
Inferior alveolar nerve block - important to anesthetize?
important you also numb the long buccal nerve as this is supplying the buccal mucosa and also the buccal gingival tissue adjacent to the mandibular molars
long buccal nerve distribution
GSA - proprioception of skin of cheek, buccal mucosa, buccal gingival tissue adjacent to mandibular molars
lingual nerve distribution
GSA - proprioception to anterior 2/3 of tongue, floor of oral cavity, mandibular lingual gingival tissue
inferior alveolar nerve travels? distribution
in the mandibular canal and then enters the mandibular foramen – then GSA fibers for mandibular molars and 2nd pre molar, with few gingival branches
Mental nerve distribution
skin of chin and lower lip, labial mucosa, labial gingival tissue adjacent to premolars, canine and incisors
will go through the mental foramen
insicive nerve distribution
1st mandibular premolar, canine, and incisors
location of mental foramen
inferior to 2nd premolar
T/F the distribution of the long buccal nerve would not be anesthetized with an inferior alveolar nerve block
TRUE - long buccal nerve is supplying buccal gingiva of the mandibular molars
V3 is the only part of CN V that includes what type of resident fibers
SVE - going to muscles of mastication from the first pharyngeal arch
Parasympathetic acquired fibers for V3 - general
from lesser petrosal nerve (CN IX) and chorda tympani from (CN VII)
Course of lesser petrosal nerve (from CN IX) and its contributions
supplies GVE fibers for V3
Comes through foramen ovale –> to otic ganglion (synapse) and post ganglionic parasympathetic fibers join with the auriculotemporal nerve and supply GVE to the Parotid gland
Course of chorda tympani nerve (from CN VII) and its contributions
Fibers from chorda tympani from CN VII enter the lingual nerve
will go to the submandibular ganglion and SYNAPSE and supply the submandibular gland and some fibers go back into lingual nerve (stay here) and pass to the sublingual gland and glands of oral cavity
Sympathetic GVE fibers of V3
V3 acquires sympathetic GVE fibers from external carotid artery and its plexus to reach the partoid gland - more come from this than the auriculotemporal nerve that receives GVE vis the middle meningeal artery (more from ECA) and also facialartery contributign to GVE in the submandiular and sublingual glands
- will pass through the submandibular ganglion WITHOUT SYNAPSING
lesion of CN VII as it leaves brainste? what does this do for taste
you would lose taste to the anterior 2/3 of the tongue - because these fibers supply the SA fibers to the lingual nerve of V3 that is doing taste for anterior 2/3
WOULD NOT LOSE GENERAL SENSATION - GSA FIBERS TO THE TONGUE BECAUSE THIS IS FROM CN V
lesion to the lingual nerve WITHIN oral cavity
would still lose taste to the anterior 2/3 of the tongue - carrying the SA fibers from the chorda tympani of CN VII
AND GENERAL SENSATION - GSA FIBERS
lesion of CN V at the brainstem
patient can still taste - but loss of general sensation due to no GSA fibers
SA fibers are through CN VII - so can still taste
lesion to lingual once the lingual nerve has sa fibers
loss of taste
loss of general sensation
decrease of saliva production becuase lingual going to submandibular and sublingual
sympathetic GVE fibers associated with v3
acquired
most fibers reach the parotid gland via the external carotid artery and its branches, - few via the auriculotemporal nerve
- some that go to parotid are also from the middle meningeal artery
facial artery is contributing to the sublingual and submandibular sympathetic innervation
general rule with sympathetic fibers
GVE SYMPATHETIC - all those come from the superior cervical ganglion and TRAVEL ALONG SOME BLOOD VESSEL TO GET TO THEIR TARGET
PASSING TO THE REGION OF GLANDS
where are the taste fibers sacquired
in the infratemporal fossa
