Trigeminal Nerve 1 Flashcards
What cranial nerve is the trigeminal
5
Does the trigeminal nerve have sensory or motor routes
both
What are the 3 divisions of the trigeminal nerve
ophthalmic nerve
maxillary nerve
mandibular nerve
What divisions of the trigmeninal are targeted by the local anesthesia
maxillary and mandibular
What is the osteology that needs to be known when looking at the skull anteriorly
supraorbital notch (foramen)
zygomatic bone
mental foramen
What exits through the supra orbital notch/foramen
the supra orbital nerve
What is the supra orbital nerve
a continuation of the frontal nerve (ophthalmic)
What passes through the infraorbital foramen
the infra orbital nerve
What is the infra orbital nerve
a branch of the maxillary nerve
What passes through the mental foramen
it transmits the terminal branches of the inferior alveolar nerve (and the mental artery)
When looking at the osteology of the hard palate what should you be able to identify
should be able to differentiate between the maxilla and the palatine bone
incisive foramen
greater palatine foramen
lesser palatine foramen
What passes through the incisive foramen
the nasopalatine nerve
What passes through the greater palatine foramen
greater palatine nerve
What passes through the lesser palatine foramen
lesser palatine nerve
What are the key features of the mandible
it is the site of attachment for several muscles
it has foramina for the passage of neuromuscular structures
it has teeth in the alveolar processes
What do you need to be able to identify on the mandible
condylar process
coronoid process
mental foramen
What is the condylar process
forms part of the TMJ
can be felt when asking patient to open and close their mouth
What is the coronoid process
site of attachment for the temporals
What should you be able to identify on the medial site of the mandible
lingula
mandibular foramen
Why is the lingula significant
it can be felt easily
What is the mandibular foramen for
it allows the passage of the inferior alveolar nerve
Where does the trigeminal nerve exit
at the mid pons
What are the 2 components in terms of information that the trigeminal transmits from the periphery to the brainstem
special visceral efferent
general somatic afferent
What is the special visceral efferent
it is efferent because it is motor information comes from the motor nucleus
Where is the motor nucleus of the trigeminal
at the level of the pons
What is the special visceral efferent information to
predominantly the muscles of mastication
What are the 3 different brainstem nuclei that information that general somatic afferent info is sent to
mesencephalic nuclei
chief sensory nuclei
spinal nuclei
Where is the mesencephalic nuclei found
in the mid brain
What is the mesencephalic nuclei for
proprioception
What is the chief sensory nuclei found
in the pons
What is the chief sensory nuclei for
discriminative touch
Where is the spinal nucleus found
founding the medulla oblongata
What is the spinal nucleus for
For pain and temperature for structures supplied by the trigeminal as well as general conscious sensation for the viscera supplied by cranial nerves 9 and 10
What is a ganglion
w A ganglion is when all the fibres of the trigeminal nerve are together and before the trigeminal nerve divides into it’s 3 divisions
What is the cavity in the dura mater that the trigeminal ganglion occupies called
MECKELS CAVE
Describe the course of the trigeminal nerve as it approaches the ganglion
The nerve roots of CN V emerge from the mid pons and pass forwards onto the apex of the petrous temporal bone where the trigeminal ganglion lies in a cave of dura mater (Meckel’s cave)
What does the first division of the trigeminal nerve pass through
superior orbital fissure
What does the second division of the trigeminal nerve pass through
foramen rotundum
What does the third division of the trigeminal nerve pass through
foramen ovale
What is the trigeminal ganglion close to
the cavernous sinus
What branches of the trigeminal nerve pass through the cavernous sinus
V1 and V2 pass anteriorly in the lateral wall fo the cavernous sinus to reach the superior orbital fissure and foramen rotunda respectively
If a patient has an injury that effects all 3 divisions of the trigeminal nerve what is it likely to be
injury somewhere in the pons e.g stroke
injury at the cranial base e.g trauma or tumor
In the cavernous sinus, what is the trigeminal nerve close to
the internal carotid artery and its sympathetic plexus
What is the significance of the trigeminal nerves close proximity to the internal carotid artery
a clot forming in this artery can result in compression of the nerve
If the divisions of the trigeminal nerve are affected in the cavernous sinus then what is usually also effected
the other nerves present
Cn3, 4 and 6
usually severe issues seen in the eye
What is the course of the ophthalmic nerve
passes anteriorly in the lateral wall of the cavernous sinus to reach the superior orbital fissure
once inside the orbit it divides into the different divisions
What does the ophthalmic division provide sensorial innervation to
scalp, eye, upper face and sinuses
What are the main branches of the ophthalmic branch
frontal
lacrimal
nasociliary
What does the frontal nerve branch into
supraorbital
supratrochlear
What does the terminal branches nasociliary nerve branch into
infratrochlear
external nasal
What are the TERMINAL branches of the ophthalmic nerve
supraorbital supratrochlear lacrimal infratrochlear external nasal
What do the supraorbital and supratrochlear nerve provide sensation to
different parts of the forehead
provide sensation to the skin of the vertex (the scalp) and the upper eyelid/forehead
What does the lacrimal nerve supply
Lacrimal nerve innervates the lacrimal gland and skin of the lateral and upper eyelid and forehead
What is the external nasal nerve a continuation of
the external nasal nerve is a CONTINUATION of the anterior ethmoidal nerve which comes off the nasociliary nerve
What does the external nasal nerve supply
tip of the nose
What does the infratrochlear nerve supply
the skin at the medial angle of the eye and adjacent root of nose
What is the significance of the nasociliary supplying both the tip of the nose and the cornea
Should the shingles appear at the tip of the nose then this may be a warning that the disease will also develop on the cornea which could result in loss of sight
What is shingles
Shingles is due to the virus that causes chickenpox (varicella-zoster virus) which sits dormant on the trigeminal ganglion but when it reactivates it is known as shingles which can present on any division of the trigeminal nerve
What does CN V1 supply in relation to the eye
the skin of the upper eyelid, underlying conjuctiva both on the eyelid and over the cornea
What part does Cn V1 play in the corneal reflex
the sensorial part of the reflex is the nasociliary nerve
motor part is the facial nerve
What do the ethmoidal nerves (anterior and posterior) supply
ethmoidal sinuses, lateral wall of the nasal cavity and nasal septum)
What is the course of the maxillary division
N V2 passes anteriorly in the lateral wall of the cavernous sinus and reaches the PTERYGOPALATINE FOSSA via the foramen rotundum
What is the foramen rotunda also called
the middle cranial fossa
What is the foramen rotundum hidden in
the pterygopalatine fossa
Where does the pterygopalatine fossa lie
just lateral to the upper aspect of the nasal cavity & nasopharynx behind the orbit and above the hard/soft palate
What does the pterygomaxillary fissure do
w The pterygomaxillary fissure gives entry to the pterygopalatine fossa
Where can the sphenopalatine foramen be found
in the medial wall of the pterygopalatine fossa
What are the 2 main branches of the maxillary division
zygomatic
infra orbital
What are the other important branches of the maxillary division
nasopalatine
greater and lesser palatine to the palate
alveolar to the upper teeth
What does the zygomatic nerve branch into
○ Zygomaticotemporal (to the temple)
Zygomaticofacial (further down the face)
What does the infraorbital go down to
upper lip
What do the anterior superior alveolar nerve and middle superior alveolar nerves branch from
the infraorbital
Does the posterior superior alveolar branch from the infraorbital?
No
it is its own branch
What does the palatine nerve go through
the palatine canal
gives off the greater and lesser palatine nerves
Where does the nasal nerve go
disappears in the sphenopalatine foramen
What does CNV2 send the zygomatic and infraorbital branches
into the orbit via the INFERIOR ORBITAL FISSURE
Where does the infraorbital branch exit
through the intra orbital foramen
Where does the zygomatic branch exit
The zygomatic branch divides into the zygomaticotemporal and zygomaticofacial nerve which then exit the orbit using identically named foramina.
What does CNV2 supply
parts of the nasal cavity, nasopharynx, maxillary sinus, hard and soft palate, upper teeth and gums
Describe the course of the nasopalatine nerve
Trigeminal nerve exits at the pons > second division exits through the foramen rotundum > goes through the pterygopalatine fossa > goes through the sphenopalatine foramen (foramen in the pterygopalatine fossa) to reach the nasal cavity, into the septum and passes inferiorly to reach the anterior hard palate and exits through the incisive foramen
What does the nasopalatine nerve enter the hard palate through
INCISIVE CANAL
What are the 3 alveolar branches
anterior superior alveolar
middle superior alveolar
posterior superior alveolar
What is the course of the posterior superior alveolar
The pterygomaxillary fissure connects the infratemporal fossa with the pterygopalatine fossa which transmits the posterior superior alveolar nerve. It exits through the fissure into the temporal fossa
What are the 2 palatine branches
○ Greater palatine
Lesser palatine
What is the course of the palatine nerves
They pass through the palatine fossa, go through the palatine canal and exit through the corresponding foramen (greater palatine foramen and lesser palatine foramen) that are found on the hard palate
Where are the palatine nerves found
They are found on the lateral wall of the nasal cavity unlike the nasopalatine
What are the upper teeth innervated by
Anterior superior alveolar nerve
Middle superior alveolar nerve
Posterior superior alveolar nerve
What is the upper labial gingiva innervated by
by the same nerve that supplies the tooth
What does the nasopalatine nerve innervate regarding the gingiva
innervates the mucosa surrounding the incisive papilla and the palatal gingival margins of the anterior teeth
What does the greater palatine nerve innervate regarding the gingiva
innervates the palatal tissues and the palatal gingiva posterior to the canines after passing through the greater palatine foramen
What do the greater palatine nerve and nasopalatine supply in regards to the hard palate
they overlap in their innervation of it
What does the lesser palatine nerve supply
the soft palate and uvula
