Trigeminal Nerve Flashcards
What are the skull exit points for each of the trigeminal branches?
ophthalmic = supra-orbital foramen (notch)
maxillary = infra-orbital foramen
mandibular = mental foramen
What foramen are found in the hard palate?
incisive (most anterior)
greater palatine
lesser palatine (most posterior)
What bones make up the hard palate?
Palatine bone (posterior part)
Maxilla - Palatine process (anterior part)
What are the roles of the mandible in relation to sites?
- Site for muscle attachments
- Foramina for passage of
neurovascular structures - Teeth in alveolar processes
What is the lingula and where is it?
a prominent bony ridge on the medial side of the mandible anterior to the mandibular foramen
Where in the brain stem does the special visceral efferent travel?
from the motor nucleus in the pons to the muscles of mastication
Where does the general somatic afferent travel to?
to the mesencephalic, chief sensory & spinal nuclei in the midbrain, pons & medulla oblongata
What are the 4 nuclei?
where are they in the brainstem
Mesencephalic Nucleus: - Midbrain
Principal (Cheif) Sensory Nucleus: - Pons
Motor Nucleus: - Pons
Spinal Trigeminal Nucleus: - Pons and Cervical levels of the spinal cord
Where does the trigeminal ganglion lie?
region and cavity
Region: Middle cranial fossa
Cavity: Meckel’s cave (trigeminal cave)
What is meckel’s cave and where is it?
cave of dura mater at apex of the petrous temporal bone
If all 3 divisions are affected by something, where is the lesion?
lesion
the lesion must be in the pons (i.e. stroke) or at the cranial base (i.e. trauma or tumour)
What divisions travel through the lateral wall of the cavernous sinus
Ophthalmic (V1) and maxillary (V2) branches of the trigeminal nerve
If divisions in the cavernous sinus are affected, what other cranial nerves might be affected?
vestibulocochlear (8)
trochlear nerve (4)
In the cavernous sinuses, what is close to the roots of the trigeminal nerve?
internal carotid artery & its sympathetic plexus
What does the opthalamic pass through (after the cavernous sinus) to give off it’s 3 branches?
superior orbital fissue
What are the 3 branches of ophthalmic division?
frontal
lacrimal
nasociliary
What branches does the frontal nerve give off?
supraorbital
supratrochlear
What sensory innervation does the lacrimal nerve give?
lacrimal gland & skin of lateral upper eyelid & forehead
What branches does the nasociliary nerve give off?
long ciliary nerve(s)
anterior & posterior ethmoidal nerves
infratrochlear nerve
What is the external nasal nerve a continuation of?
anterior ethmoidal nerve
What do the supratrochlear and supraorbital supply?
forehead, upper eyelids, and scalp
What does the external nasal nerve supply?
skin at the tip of the nose
What does the infratrochlear nerve supply?
skin at the medial angle of the eye and adjacent root of nose
In addition to the external nasal branch, what does the nasociliary nerve provide sensation to?
Why is that clinically relavant?
The nasociliary nerve also supplies sensation to the cornea of the eye via long ciliary nerves
Shingles at the tip of the nose may be a warning that the disease will also develop on the cornea
What branch of V1 brings about the corneal reflex?
nasociliary
What does V1 supply in the eye?
supply the skin of the upper eyelid, they also supply the underlying conjunctiva both on the eyelid & over the cornea
What do the ethmoidal nerves supply?
ethmoidal sinuses, lateral wall of nasal cavity & nasal septum (tip of the nose via external)
Where does V2 pass so it can give off it’s branches?
foramen rotundum
What does V2 reach after the foramen rotundum?
pterygopalatine fossa
What is medial to the pterygpalatine fossa?
sphenopalatine foramen
What are the main branches of V2?
zygomatic
infra-orbital
Apart from the main branches, what other branches does V2 have?
nasopalatine to nasal cavity
greater and lesser palatine to palate
alveolar (branches) to upper teeth
What does V2 supply in addition to the skin?
the nasal cavity, nasopharynx, maxillary sinus, hard & soft palate, upper teeth & gingiva
Where does the infraorbital nerve emerge and what does it supply?
merges from the infraorbital foramen to supply the lower eyelid, cheek, nose & upper lip
What are the branches of the zygomatic nerve?
zygomaticofacial nerve
zygomaticotemporal nerve
Where does the nasopalatine enter from and what is it’s course/destination?
enters the nasal cavity via the sphenopalatine foramen to reach the nasal septum passes via the incisive canal and finially reaches the anterior hard palate
What are the alveolar branches of the V2?
anterior superior
middle superior
posterior superior
What are the palatine branches of V2?
greater
lesser
What provides sensory supply to the teeth from V2?
anterior superior alveolar nerve
middle superior alveolar nerve
posterior superior alveolar nerve
What provides sensory supply to the gingivae from V2?
nasopalatine nerve
anterior superior alveolar nerve
middle superior alveolar nerve
posterior superior alveolar nerve
greater palatine nerve
What provides the palate with general sensation?
greater palatine nerve (hard palate)
lesser palatine nerve (soft palate)
nasopalataine nerve (hard palate)
What is the course of the mandibular division (V3) of the trigeminal nerve?
CN V3 passes through the foramen ovale & into the infratemporal fossa where it gives several branches
Where is the foramen ovale located?
middle cranial fossa
What is the skin over the angle of the mandile supplied by?
(not CV)
cervical plexus with the great auricular nerve (C2,3)
What are the trunks of V3?
main
posterior
anterior
What branches does the main trunk of CV3 give off?
before division
meningeal branch (sensory)
branch to tensor tympani
branch to medial pterygoid
branch to tensor veli palatini
What branch of the main trunk (CV3) is sensory?
All motor apart from the meningeal nerve that is sensory to the dura mater
What branches does the anterior trunk of CV3 give off?
deep temporal nerves
nerve to lateral pterygoid
buccal nerve (not facial branch)
massteteric nerve
What branch of the anterior trunk (CV3) is sensory?
all motor except buccal nerve which is sensory
What branches does the posterior trunk of CV3 give off?
lingual nerve
inferior alveolar
auriculotemporial
What branch of the posterior trunk (CV3) is motor?
All sensory apart from the inferior alveolar nerve that is mixed (sensory & motor)
What does V3 provide general sensation to?
the floor of the mouth along with the lower teeth & gums
the anterior 2/3rd of the tongue via the lingual nerve
What does the lingual nerve carry?
chorda tympani nerve which is a branch of CN VII
What is trigeminal neuralgia?
what distribution does it occur in
terrible pain usually in CN V3 & occasionally in CN V2 distribution
What branch provdes general sensation to the cheek and lateral gum?
buccal nerve
What branch/s provide general sensation to lower teeth, and the skin of chin and lower lip?
lower teeth = incisive nerve (branch of IAN) / main trunk of IAN
skin of chin and lower lip = mental nerve (branch of IAN)
What motor supply does the inferior alveolar nerve provide?
supplies the mylohyoid & anterior belly of digastric
After it’s motor branches, where does the IAN go?
enters the mandibular foramen to supply general sensation to the lower teeth
What branches provide general sensation to the gingivae?
lingual nerve
buccal nerve
mental nerve from IAN
From both V2 and V3, what nerves provide general sensation to the teeth?
anterior superior alveolar nerve
middle superior alveolar nerve
posterior superior alveolar nerve
incisive nerve
IAN in mandiular canal
What provides special sensation (taste) to the tongue?
facial nerve (chorda tympani branch)
What muscles does V3 provide motor innvervation to?
lateral/medial pterygoid
deep temporal
massesteric
(MOM)
tensor tympani (muscle in the middle ear)
tensor palati(the latter via the branch to medial pterygoid)
mylohyoid
anterior belly of digastric (via inferior alveolar branch)
What is reactivation of Varicella virus in trigeminal gangelion called ?
shingles
How does varicella present?
Cutaneous involvement in the distribution of CN V1
Erythematous, vesicular, crusting rash & burning
sensation
What is hutchinson’s sign?
cutaneous involvement of the tip of the nose (external nasal branch of nasociliary nerve)
What does a positive hutchinson’s sign increase?
A positive Hutchinson’s sign increases the likelihood of
ocular complications (nasociliary nerve)
Conjunctivitis, keratitis (cornea) & uveitis (anterior chamber of globe)
What does the facial nerve supply?
all the muscle of facial expression
What are the exit points of each trunk from the middle cranial fossa
Ophthalmic = superior orbital fissure
Maxillary = foramen rotundum
Mandibular = foramen ovale
