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)