Trigeminal nerve 1 Flashcards
What are the sensory functions of the trigeminal nerve
- skin of face
- oral mucosa
- nasal mucosa
- sinus mucosa
- teeth
what are the motor functions of the trigeminal nerve
- muscles of mastication
- 4 others
what functions of the trigeminal nerve are we particularly interested in
sensory functions (motor is more to be aware of incase of damage)
what cranial nerve is the trigeminal nerve
CNV
what are the 3 main branches of the trigeminal nerve
CNV1 - opthalmic
CNV2 - maxillary
CNV3 - mandibular
which main branches of the trigeminal nerve do we delivery anaesthesia to
maxillary and mandibular (opthalmic to be aware of as could affect others)
what are the 3 exit points of the trigeminal nerve
- supra-orbital notch (foramen)
- infra-orbital foramen
- mental foramen
what is the difference between a notch and a foramen
notch - semi-circular opening
foramen - hole
exit point of opthalmic branch
supra-orbital notch
exit point of maxillary branch
infra-orbital foramen
exit point of mandibular branch
mental foramen
what bones make up the hard palate
- palatine process of maxilla
- horizontal plate of palatine bone
what foramens are in the hard palate (know positions)
- incisive foramen (in between central incisors)
- greater palatine foramen (x2) (near posterior molars)
- lesser palatine foramen (x2) (near posterior molars)
what nerve passes through the mandibular foramen
inferior alveolar nerve
what foramen does the inferior alveolar nerve pass through
mandibular foramen
What landmarks on the mandible should I definitely know
body
- angle
- ramus
- condylar process
- head
- neck
- lingula
- mandibular foramen
- coronoid process
Where does the trigeminal nerve exit on the base of the brain and skull
the pons of the brainstem
What are the different nuclei and modalities of the trigeminal nerve
Special visceral efferent from the motor nucleus in the pons to the muscles of mastication
General somatic afferent to the mesencephalic (midbrain), chief sensory (pons) and spinal nuclei (medulla)
where does general somatic afferent (sensory) information come from regarding the trigeminal nerve
3 different brainstem nuclei (midbrain, pons and medulla). Spans the human brainstem. Fibres come together and exit at the pons. Different sensory info is processed at different points in the brain
What does the trigeminal motor nucleus control
muscles of mastication
What does the CNV mesencephalic nucleus control
proprioception
What does the CNV chief sensory nucleus control
discriminative touch
What does the CNV spinal nucleus control
pain and temperature for structures supplied by CNV as well as general conscious sensation for the viscera supplied by CN IX and X
what brainstem nuclei are we most interested in
- chief sensory nucleus (discriminative touch)
- spinal nucleus (pain and temperature)
(exit half way through pons)
When assessing the trigeminal nerve what must you do
test CNV1,2 and 3 individually
Where do the trigeminal nerve roots emerge from and go to
emerge from mid pons
pass forwards onto the apex of the petrous temporal bone where the trigeminal ganglion lies in a cave of dura mater (Meckel’s cave)
where does the trigeminal ganglion lie
Meckel’s cave (cave of dura mater)
where is Meckel’s cave
on the apex of the petrous temporal bone
After dividing from the trigeminal ganglion where does CNV1 pass
towards the superior orbital fissure
After dividing from the trigeminal ganglion where does CNV2 pass
through the foramen rotundum
After dividing from the trigeminal ganglion where does CNV3 pass
through the foramen ovale
If all 3 CNV divisions are affected, where must the lesion be
in the pons (i.e. a stroke) or at the cranial base (i.e. trauma or tumour)
What are the 3 main and 5 sensory branches of the opthalmic branch
- Frontal (supratrochlear, supra-orbital)
- Lacrimal
- Nasociliary (infratrochlear, external nasal)
What does the opthalmic divison carry
Parasympathetics via ciliary ganglion to eye for accomodation and pupil constriction, via pterygopalatine ganglion for lacrimal gland
Sympathetics via cavernous sinus to pupil for dilation
Where does the frontal nerve go
- divides into supra-orbital and supra trochlear
- skin of vertex
- upper eyelid/forehead
Where does the lacrimal nerve go
- lacrimal gland
- skin of lateral upper eyelid and forehead
Where does the nasociliary nerve go
- gives off long ciliary nerve(s), anterior and posterior ethmoidal nerves
- then continues as the infratrochlear nerve to skin of medial upper eyelid and root of nose (external nasal nerve)
What does the supratrochlear, supraorbital and lacrimal nerves supply
- the vertex
- forehead
- upper eyelids
What does the anterior ethmoidal nerve continue as
external nasal nerve to the skin at the tip of the nose
What does the infratrochlear nerve supply
the skin at the medial angle of the eye and adjacent root of the nose
What division of the trigeminal nerve can shingles affect
any!
what does shingles at the tip of the nose indicate, why?
a warning that the disease will also develop on the cornea
because the nasociliary nerve that innervates the tip of the nose also supplies the cornea and the conjunctiva (if you don’t treat could lose eyesight)
What nerves supply blinking
- CNV1 (first limb of coneal reflex)
2. facial nerve (actual blink)
Where does the maxillary division pass following the trigeminal ganglion
passes anteriorly in the lateral wall of the cavernous sinus and reaches pterygopalatine fossa via the foramen rotundum
What division of the trigeminal nerve enters through the foramen rotundum
maxillary division (CNV2)
what does the maxillary division reach after passing through the foramen rotundum
pterygopalatine fossa
where is the pterygopalatine fossa
lies just lateral to the upper aspect of the nasal cavity and nasopharynx behind the orbit and above the hard/soft palate
what is the opening of the pterygopalatine fossa called
pterygopalatine fissure
where is the sphenopalatine foramen
in medial wall of pterygopalatine fossa
what landmarks in the pterygopalatine fossa should we know
- sphenopalatine foramen
- foramen rotundum
- palatine canal
What are the main branches of the maxillary division
- Zygomatic (zygomatico-temporal, zygomatico-facial)
- infra-orbital
what sensory info does the maxillary division provide
- middle face
- palate
- sinuses
- nasopharynx
- nose
what does the maxillary division carry
Parasympathetics via pterygopalatine ganglion to lacrimal gland, mucous glands of nose, palate, nasopharnynx
taste - hard and soft palate
other important features of maxillary branch other than main branches
- nasopalatine to nasal cavity
- greater and lesser palatine to palate
- pharyngeal to nasopharnx
- alveolar to upper teeth
where does the infraorbital nerve emerge from
the infraorbital foramen
what does the infraorbital nerve supply
- the lower eyelid
- cheek
- nose
- upper lip
what does the zygomaticotemporal nerve supply
anterior temple
what does the zygomaticofacial nerve supply
zygoma
What happens to the nasopalatine nerve
- enters the nasal cavity via the sphenopalatine foramen
- to reach the nasal septum from where courses inferiorly and passes via the incisive canal to reach the anterior hard palate
what are the alveolar branches of maxillary and what nerve do they come from
come from infraorbital branch of maxillary (anterior and middle)
- anterior superior alveolar
- middle superior alveolar
- posterior superior alveolar (separate from infra-orbital)
What are the palatine branches of maxillary
- greater palatine
- lesser palatine
where are the palatine branches found
lateral nasal wall
What nerve supplies upper teeth 1-3
anterior superior alveolar nerve (from V2)
What nerve supplies upper teeth 4-5
middle superior alveolar nerve (from V2)
What nerve supplies upper teeth 6-8
posterior superior alveolar nerve (from V2)
What teeth does the anterior superior alveolar nerve supply
maxillary 1-3
What teeth does the middle superior alveolar nerve supply
maxillary 4-5
What teeth does the posterior superior alveolar nerve supply
maxillary 6-8
what part of the gingiva does the nasopalatine nerve supply
palatal side of maxillary 1-3
what part of the gingiva does the greater palatine nerve nerve supply
palatal side of maxillary 4-8
what does the lesser palatine nerve supply
soft palate and uvula
what part of the gingiva does the anterior superior alveolar nerve supply
buccal aspect of maxillary 1-3
what part of the gingiva does the middle superior alveolar nerve supply
buccal aspect of maxillary 4-5
what part of the gingiva does the posterior superior alveolar nerve supply
buccal aspect of maxillary 6-8
What nerve supplies upper palatal aspect of 1-3 gingiva
nasopalatine nerve
What nerve supplies upper palatal aspect of 4-8 gingiva
greater palatine nerve
What nerve supplies upper buccal aspect of 1-3 gingiva
anterior superior alveolar nerve
What nerve supplies upper buccal aspect of 4-5 gingiva
middle superior alveolar nerve
What nerve supplies upper buccal aspect of 6-8 gingiva
posterior superior alveolar nerve