Trigeminal Nerve 1 [CN1/2] Flashcards
what is cranial nerve V called
trigeminal nerve
what does the sensory root of CN V supply
skin of face
oral nasal and sinus mucosa
teeth
what does the motor root of CN V supply
muscles of mastication tensor-tympani muscle tensor palati mylohyoid anterior belly of digastric
how many divisions does CN V have
3
- ophthalmic
- maxillary
- mandibular
what are the 3 exit points where the branches of CN V exits the skull
- supra-orbital notch / foramen
- infra-orbital foramen
- mental foramen
what is the hard palate made up of
palatine process of maxilla
and
horizontal plate of palatine bone
name the foramen found in the palatine process of maxilla
incisive foramen
name the 2 foramen found in the horizontal plate of palatine bone
greater palatine foramen
lesser palatine foramen
why is the foramina in the mandible
for the passage of neurovascular structures
name the parts of the mandible from the external view
condylar process ramus angle of mandible inferior border mental foramen body oblique line anterior border superior border
name the parts of the mandible from the internal view
head neck pterygoid bone mandibular notch coronoid process mandibular foramen lingula mylohyoid groove mylohyoid bone sublingual fossa roughening for attachment of medial pterygoid muscle angle
what is the condylar process part of
TMJ
can feel it when opening and closing the mouth
what is the temporalis muscle attached to
coronoid process
what passes through the mandibular foramen
inferior alveolar nerve
what is CN V covered by when on the base of the brain and skull
dura
where does the special visceral efferent axon come from and go to
comes from the motor nucleus in the pons to the muscles of mastication
where does the general somatic afferent go
to the
- mesencephalic in the midbrain
- chief sensory in the pons
- spinal nuclei in the medulla oblongata
what does the CN V mesencephalic nucleus do
its for proprioception
tells you where your head is in space
not overly important dentally
what does the CN V cheif sensory nucleus do
for discriminative touch
what does the CN V spinal nucleus do
pain and temperature sensation for structures supplied by CN V
as well as general conscious sensation for the viscera supplied by CN IX and X
when assessing CN V, what is it important to do when testing this nerve
to test the regions of CN V individually (3 branches)
where does CN V supply general somatic sensation to
face
head
associated orbital, nasal and oral cavities
which branch of CN V contains the motor root
CN V3 / mandibular division
for the muscles of mastication
where does the ophthalmic division exit
supraorbital notch / foramen
where does the maxillary division exit
infraorbital foramen
where does the mandibular division exit
mental foramen
where is the trigeminal ganglion found
in meckel’s cave which is part of the dura
creates a protective cave
all the fibres of the trigeminal nerve are still together - this is before they divide into branches
where does the nerve roots of CN V emerge from and go
emerge from the mid-pons
pass forwards onto the apex of the petrous temporal bone where the trigeminal ganglion lies in a cave of dura mater
where does CN V1 go when it leaves the trigeminal ganglion
passes anteriorly in the lateral wall of the cavernous sinus to reach the superior orbital fissure
passes inside the human orbit
passes laterally
divides into branches inside the orbit
where does CN V2 go when it leaves the trigeminal ganglion
passes anteriorly in the lateral wall of the cavernous sinus and reaches the pterygopalatine fossa via the foramen rotundum
what is the trigeminal ganglion close to
neurovascular sites
the cavernous sinus in particular
if all 3 CN V divisions are affected, where must the lesion be?
must be in the pons (ie stroke)
or at the cranial base (ie trauma or tumour)
where does CN V3 go when it leaves the trigeminal ganglion
foramen ovale
what artery is close to CN V1 and V2 and the cavernous sinus
internal carotid artery and its sympathetic plexus
if the divisions of CN V are affected in the cavernous sinus, what other nerves can evidence of an effect be seen too?
CN III
CN IV
do we ever block the branches of CN V1 for dental treatment
no
where does CN V1 supply sensory
scalp
eye
upper face
sinuses
what does CN V1 carry
○ Parasympathetic
§ Via ciliary ganglion to eye for accommodation and pupil constriction (10 short ciliary nerves) via pterygopalatine ganglion for the lacrimal gland
§ CN V carries all parasympathetic to their end organs
§ Don’t worry about this part as much
○ Sympathetic
§ Via cavernous sinus to pulp for dilation (2 long ciliary nerves)
§ Main focus on this part
what are the main branches of CN V1
lacrimal supratrochlear supraorbital infratrochlear external nasal
what does the frontal nerve divide into and what does it supply
supraorbital
supratrochlear
sensory sensation to the skin of vertex and upper eyelid and forehead
what does the lacrimal nerve supply
sensory sensation the lacrimal gland and skin of lateral upper eyelid and forehead
important for cryiing
what does the nasociliary nerve divide into
and what do they supply
- long ciliary nerve
- anterior ethmoidal
- posterior ethmoidal
- infratrochlear
skin of medial upper eyelid and root of nose
and the continuation of the anterior ethmoidal nerve into a branch called the external nasal nerve
supplies tip of the nose
what does the supratrochlear, supra orbital and lacrimal nerves supply
vertex
forehead
upper eye lids
what does the infratrochlear nerve supply
skin at the medial angle of the eye and adjacent root of nose
how is CN V1 important in detection of shingles
shingles is a virus you get when you have chicken pox but the virus lies dormant inside the trigeminal ganglion
if virus is reactivated = shingles, can be got in any division of the trigeminal nerve
if there is a painful tingy rash at the tip of the nose this is indication that shingles is in the external nasal nerve which is supplied by the anterior ethmoidal nerve which comes from the nasociliary nerve
this rash on the tip of the nose is an warning that the cornea will develop shingles which can cause loss of eye sight
dentist in good position to clinically recognise shingles
what nerves are involved in the corneal reflex
• CN V1 is the first limb of the corneal reflex (nasociliary nerve)
○ Stimulate the cornea to blink
§ First part of reflex is the nasociliary nerve (sensory)
§ The closing of the eye (blink) is mediated by the facial nerve (CN VII) (motor)
what do the ethmoidal nerves supply
ethmoidal sinuses
lateral wall of nasal cavity
nasal septum
what does CN V2 supply
substantial sensory supply to the maxilla, upper teeth and gingiva
what does CN V2 pass through to enter the pterygopalatine fossa
foramen rotundum
where is the pterygopalatine fossa found
Lies just lateral to the upper aspect of the nasal cavity and nasopharynx behind the orbit and above the hard / soft palate
what is in the medial wal of the pterygopalatine fossa
sphenopalatine foramen
where is the pterygomaxillary fissure found
leads to the pterygopalatine fossa
with spehnopalatine foramen medial to this fossa
diagrams
some havent got Qs about them so make sure to look at them so you can label them
where does CN V2 give sensory supply
middle face palate sinuses nasopharynx nose
what does CN V2 carry
○ Parasympathetic
Via pterygopalatine ganglion to lacrimal gland, mucous glands of nose, palate, nasopharynx
where does CN V2 supply taste sensation
hard and soft palate
name branches of CN V2
zygomaticotemporal zygomaticalfacial infraorbital anterior superior alveolar middle superior alveolar posterior superior alveolar lesser palatine greater palatine
what does the nasopalatine nerve supply
nasal cavity
what does the greater and lesser palatine nerves supply
palate
what does the pharyngeal nerve supply
nasopharynx
what does the alveolar nerve supply
upper teeth
what does the zygomatic nerve divide into
zygomaticotemporal
zygomaticofacial
the CN V2 divides to send zygomatic and infraorbital branches where
into the orbit
via the inferior orbital fissure
that then emergy through bony foramine to supply the skin
also supplies parts of the nasal cavity, nasopharynz, maxillary sinus, hard and soft palate, upper teeth and gums
describe the course and innervation of infraorbital nerve
emerges from the infraorbital foramen to supply the lower eyelid, cheek, nose and upper lip
describe the course and innervation of the nasopalatine nerve
enters the nasal cavity via the sphenopalatine foramen to reach the nasal septum
it then travels inferiorly and passes via the incisive canal to reach the anterior hard palate
what can be found on the lateral side of the pterygopalatine fossa
think of it as a box
there is an opening inside the nasal cavity on the lateral size of the box called the sphenopalatine foramen and the nasal nerve enters this opening to reach the nasal cavity
where does the anterior superior and middle superior nerve come from
infraorbital branch
where does the posterior superior nerve come from
maxilla division
nothing to do with infraorbitla branch
where does the palatine branch travel
palatine fossa palatine canal separates into greater and lesser then exit through corresponding foramen - greater palatine foramen - lesser palatine foramen
where is the palatine canal found
roof of oral cavity (palate)
explain the general sensory supply of the upper teeth
anterior superior alveolar nerve (CN V2) supplies anteriors = canines and incisors
middle superior alveolar nerve supplies premolars
posterior superior alveolar supplies molars
explain the general sensory supply of the upper gingiva
nasopalatine nerve supplies palatal gingiva
anterior superior alveolar supplies anterior labial gingiva
middlle superior alveolar supplies the (posterior / premolar) buccal gingival
posterior superior alveolar supplies the buccal gingiva of the molars
greater palatine nerve supplies palatine gingiva from premolars to molars
what is the lesser palatine nerve important for
sensory supply to the soft palate and uvula
