Trigeminal Nerve Flashcards
Name the 3 major divisions of the trigeminal nerve
opthalmic, maxillary and mandibular
Name function of opthalmic nerve and where does it exit?
somatic sensory, exits superorbital fissue
Name nerves that branch off the opthalmic nerve
Tentorial n
Nasociliary N
Frontal N
Lacramal N
What does the tentorial n innervate and where is it located?
in the middle cranial fossa, serves dura mater of tentorial cerebelli
How does the Nasociliary N branch? Where does it originate in?
sensory fibers to cilliary ganglion Long cilliary root Posterior ethmoid Anterior ethmoid Infratrochlear n
Sensory root of the cilliary ganglion route and function:
V1 -> nasocilliary -> sensory root ganglion - sensory fibers that pass through the cilliary ganglion to subserve structures within the eye.
Long cilliary root route and function:
- alt route for sensory fibers to eyeball
posterior ethmoid nerve route and function:
- from Nasociliary n -> transits small foramina on the media surface of the orbit (through frontal bone near its junction with the orbital plate of the ethmoid bone
- Subserves the ethmoidal aircells and sphenoid sinus
anterior ethmoidal nerve route and function
- from Nasociliary n -> transits small foramina on the media surface of the orbit (through frontal bone near its junction with the orbital plate of the ethmoid bone
- Subserves the ethmoidal aircells and sphenoid sinus
- Small branches transit through the ethmoid bone and subserve skinover the superior rim of nose (external branches of the anterior ethmoid nerve) and some subserve the dura mater (anterior meningeal branch of the anterior ethmoid nerve)
Descirbe the Frontal nerve
splits into supraorbital n and supratrochlear nerve from v1 after it passes through the superior orbital fissure
Supraorbital n
from v1 -> frontal n. originates in orbit. larger than supratrochlear n, subserves skin of the forehead; more lateral than supratrochlear
Supratrochlear n.
from v1-> frontal n. smaller than frontal n. near medial edge of orbital rim. subserves medial portions of the skin of the forehead. more medial than supraorbital n
Lacrimal n
originates in orbital fissure from v1. subserves lacrimal gland (sensory). located on lateral edge of orbital rim. subserves small patch of skin superior and lateral to the eye
Describe the maxillary nerve and route.
Entirely somatic sensory in function; exits the middle cranial fossa via the foramen rotundum.
What are the branches of the maxillary nerve?
A. Meningeal branch of the Maxillary Nerve
B. Zygomatic nerve – originates within the orbit
C. Ganglionic branches to the pterygopalatine ganglion
D. Posterior superior alveolar nerve
E. Middle superior alveolar nerve
F. Anterior superior alveolar nerve
G. Infraorbital nerve
Meningeal branch of the Maxillary Nerve originates from and does what?
- Originates within the middle cranial fossa
* Subserves the dura mater of medial portions of the anterior and middle cranial fossae.
Zygomatic nerve originates from where and does what?
– originates within the orbit
Gives off two branches:
1. Zygomaticotemporal nerve
2. Zygomaticofacial nerve
Zygomaticotemporal nerve route and function?
• Forms the “cummuncating branch of the zygomaticotemporal nerve” that carries hitchhiking post-ganglionic parasympathetic fibers to the
lacrimal nerve (which then innervate the glandular cells of the lacrimal gland)
• Transits the zygomaticotemporal foramen of the zygomatic bone to subserve the skin overlying the superior zygoma
Zygomaticofacial nerve route and function?
transits the zygomaticofacial foramen of the
zygomatic bone to subserve the skin overlying the inferior zygoma
Ganglionic branches to the pterygopalatine ganglion has what type of fibers and what branches off of it?
– contains sensory fibers that pass through the pterygopalatine ganglion to enter one of the
following nerves.
1. Greater palatine nerve
- Lesser palatine nerve
- Nasopalatine nerve
- Posterior superior lateral nasal branch of the maxillary nerve
Greater palatine nerve originates in and does what?
• Originates within the sphenopalatine fossa
• Gives rise to posterior inferior lateral nasal branch of the greater palatine nerve that subserves the inferior-lateral portions of the nasal cavities (i.e., the inferior nasal cocha)
• Transits through the greater palatine foramen (at the junction of the horizontal plate of the palatine bone and the maxillary bone) to enter the
oral cavity
• Subserves the oral mucosa of the hard palate on the roof of the mouth
• Communicates with the nasopalatine nerve through the incisive foramen of the maxillary bone
- Lesser palatine nerve originates in and does what?
- Originates within the sphenopalatine fossa
- Transits through the lesser palatine foramen on the horizontal plate of the palatine bone
- Subserves the oral mucosa of the soft palate on the roof of the mouth
Nasopalatine nerve originates in and does what?
- Originates from the pterygopalatine ganglion (or greater palatine nerve)
- Subserves the nasal mucosa of the nasal septum
- Communicates with the greater palatine neve through the incisive foramen of the maxillary bone
Posterior superior alveolar nerve originates in and does what?
- Originates within the sphenopalatine fossa
- Transits through the posterior superior alveolar foramen of the maxillary bone
- Subserves the nasal mucosa of the maxillary sinus and the upper teeth
- Communicates with the middle and anterior superior alveolar nerves within the maxillary bone
Middle superior alveolar nerve originates in and does what?
- Originates within the orbit
- Transits through the middle superior alveolar foramen of the maxillary bone
- Subserves the nasal mucosa of the maxillary sinus and the upper teeth
- Communicates with the posterior and anterior superior alveolar nerves
Anterior superior alveolar nerve originates in and does what?
- Originates within the infraorbital foramen
- Transits through the anterior superior alveolar foramen of the maxillary bone
- Subserves the nasal mucosa of the maxillary sinus and the upper teeth
- Communicates with the middle and posterior superior alveolar nerves
Infraorbital nerve originates in and does what?
– transits through the infraorbital foramen to subserve the skin on the lateral portions of the nose and anterior portions of the face from the lower eyelid inferior to the upper lip
Mandibular Nerve has what kind of fibers, and what is its route?
– Contains BOTH somatic (general) sensory and branchial motor fibers;
Route: exits the middle cranial fossa via the foramen ovale
What are the branches of the Mandibular nerve?
A. Meningeal branch of the mandibular nerve
B. Auriculotemporal nerve
C. Buccal nerve
D. Lingual nerve
E. Muscular branches of the mandibular nerve
F. Inferior alveolar nerve (and Mental Nerve)
Meningeal branch of the mandibular nerve originates in and does what?
• Originates just inferior to the foramen ovale
• Re-enters the middle cranial fossa via the foramen Spinosum (a.k.a. nervus
spinosum)
• Entirely sensory; subserves the dura mater of lateral portions of the middle
cranialfossa
Auriculotemporal nerve originates in and does what?
• Originates just inferior to the foramen ovale
• Subserves lateral portions of the head, just anterior to the external auditory
meatus
Buccal nerve originates in and does what?
- Originates inferior to the foramen ovale
- Contains only somatic sensory fibers
- Subserves BOTH the inner and outer walls of the cheek
Lingual nerve originates in and does what?
- Originates inferior to the foramen ovale
- Contains only somatic sensory fibers
- Subserves the floor of the oral cavity
Muscular branches of the mandibular nerve originates in and does what?
• Originate just inferior to the foramen ovale
• Contain both branchial motor fibers innervating the named nerve, as well as
somatic sensory fibers carrying proprioceptive feedback from those muscle to
the CNS.
1. Nerve to the masseter muscle
2. Deep temporal nerves (subserve the temporalis muscle)
3. Nerve to the medial pterygoid muscle
4. Nerve to the lateral pterygoid muscle
5. Nerve to the tensor veli palatini muscle
6. Nerve to the tensor tympani muscle
Inferior alveolar nerve (and Mental Nerve) originates in and does what?
• Originates inferior to the foramen ovale
• Contains both branchial motor fibers and somatic sensory fibers
• Splits to form the mylohyoid nerve just superior to the mandibular foramen – the portion that enters the mandibular foramen is still called the inferior
alveolar nerve that will transit through the mental foramen to become the mental nerve
Mylohyoid nerve originates in and does what?
–contains both branchial motor fibers innervating the named nerve, as well as somatic sensory fibers carrying proprioceptive
feedback from those muscles to the CNS.
a. Nerve to the mylohyoid muscle
b. Nerve to the anterior belly of the digastric muscle
Inferior Alveolar Nerve (continuation in the mandibular foramen) originates in and does what?
- Contains only somatic sensory fibers
- subserves the roots of the inferior teeth
- transits through the mental foramen at the anterior end of the mandibular canal to become the mental nerve; subserves the skin on the chin and superior to the lower lip.
Summarize the dermatomal innervations of each branch of the trigeminal nerve.
V1 - Frontonasal prominence
V2 - Maxillary prominence plus the lateral and medial olfactory prominences
V3 - Mandibular prominence
Summarize the muscles innervated by the mandibular N.
2+2+4 = 8
2 tensors
• tensor tympani
• tensor veli palatini (soft palate)
2 muscles associated with mylohyoid nerve
• mylohyoid muscle
• anterior belly of the digastric muscle
4 M&M’s= muscles of mastication • masseter muscle • temporalis muscle • medial pterygoid muscle • lateral pterygoid muscle
