Trigeminal Nerve Flashcards
What branchial arch is supplied by the trigeminal nerve?
Branchial arch 1
What are the two roots of the trigeminal nerve?
The large sensory root and the small motor root
What is the name of the ganglion that contains all the sensory neuron cell bodies in the trigeminal nerve?
The Gasserian gangliion (or the trigeminal ganglion)
What are the three branches of the trigeminal?
V1 Ophthalmic
V2 Maxillary
V3 Mandibular
Through which ovale does the mandibular branch of the trigeminal leave the skull?
Through the foramen ovale, which is lateral to the cavernous sinus
What are the parasympathetic fibers that the trigeminal nerve has? Which do they carry?
The trigeminal has no parasympathetic branches of its own, but branches of V are carriers for the parasympathetics of cranial nerves III, VII, and IX
What are the 3 branches of the ophthalmic division of the trigeminal nerve?
- Frontal
- Lacrimal
- Nasociliary
What are the 2 branches that the frontal branch of the ophthalmic division branches into?
Supratrochlear branch (smaller, more medial branch) Supraorbital branch (larger, more lateral branch) Both nerves supply the scalp and send branches to upper eye
What is the path of the lacrimal branch of the ophthalmic division go through and what does it supply?
Passes through the lacrimal gland and gives off sensory twigs, ends in the palpebral branches of the upper eyelid
Where does the lacrimal branch receive parasympathetic fibers from? ***
Receives parasympathetic fibers from the pterygopalatine ganglion through the zygomatic branch of the maxillary nerve (V2)
What path does the nasociliary branch follow?
Follows the same path of the ophthalmic artery beween the superior rectus muscle and the optic nerve
What are the branches of the nasociliary branch of the ophthalmic division of the trigeminal nerve?
Long ciliary
Posterior ethmoidal
Anterior ethmoidal
Infratrochlear
What does the long ciliary nerve supply?
Major sensory nerve to eyeball and cornea.
What does the posterior ethmoidal nerve supply?
Enters posterior ethmoidal foramen and supplies sensory fibers to spheoidal air sinuses and posterior ethmoidal air cells
What does the anterior ethmoidal supply?
Is a larger branch, enters anterior ethmoidal foramen:
-where it supplies sensory fibers to the middle and anterior ethmoidal air cells
Enters cranial cavity at the side of the cribriform pate of ethmoid:
-where it sends sensory fibers to meninges
Next enters nasal cavity through nasal slit:
-gives sensory fibers to anterior part of nasal septum and anterior part of lateral walls
What does the anterior ethmoidal leave the nasal cavity as?
Leaves as the external nasal branch which supplies skin of the lower half of the nose
Where does the infratrochlear branch pass, and what does it supply?
Passes beneath trochlea, provides sensory fibers to the side of nose and medial corner of upper eyelid
What are the 3 roots of the ciliary ganglion?
Sensory root connects the nasociliary branch of the ophthalmic nerve to the ciliary ganglion
Sympathetic root which conveys postganglionic psympathetic fibers through it, and the motor (parasympathetic) root which contains preganglionci parasympathetic fibers which synapse in that ganglion
so, 1. sensory root, 2. sympathetic root, 3. parasympathetic root
Describe the path of the maxillary division of the trigeminal nerve.
It enters the lateral wall of cavernous sinus
Passes through foramen rotundum
enters pterygopalatine fossa
What is the trigeminal nerve connected to within the peterygopalaetine fossa?
It is connected to the pterygoplatine ganglion
-postganglionic parasympathetic fibers
And connected to nerve of the pterygoid canal
-Greater petrosal nerve (branch of facial) taste and pregang parasympth fibers
-Deep petrosal nerve (from internal carotid plexus, postgang sympth fibers)
What is the maxillary nerve called once it passes through the infraorbital canal?
Same nerve, but now called the infraorbital nerve, on floor of orbit
What branches arise from the pterygopalatine ganglion?
Greater and lesser palatine nerves
Posterior nasal branches and nasopalatine nerves
Pharyngeal branch
What are the 4 fiber types of the greater and lesser palatine nerves? ***
- General sensory fibers from V2 (Maxillary)
- Postganglionic parasympathetic fibers from pterygopalatine ganglion
- Taste fibers in greater petrosal branch of facial nerve for taste buds in roof of mouth
- Postganglionic sympathetic fibers from deep petrosal nerve
Through which foramen do the posteiror nasal and nasopalatine nerves of the pterygopalatine ganglion enter into the nasal cavity?
Through the sphenopalatine foramen
What types of fibers are contained in the posterior nasal branches and the nasopalatine nerves?
- General sensory fibers from V2 (Maxillary)
- Postganglionic parasympth from pterygopalatine ganglion
- Postgang sympath fibers from deep petrosal nerve
What do the nasopalatine nerves supply (branch of the pterygopalatine ganglion off of maxillary division of trigeminal)?
Supply the nasal septum
Through which foramen do nasopalatine nerves enter mouth (branch of pterygopalatine ganglion of maxillary division of trigeminal)?
Through the incisive foramen behind the upper incisor teeth and supply small anterior part of hard palate
What do the posterior nasal branches (branch of the pterygopalatine ganglion from V2 of trigeminal)?
They supply the posterior part of nasal septum and posterior wall of nasal cavity
What does the pharyngeal branch (branch of pterygopalatine ganglion from V2 of trigmeina) supply?
Supplies the mucosa and glands of nasopharynx**
What types of fibers are contained in the pharyngeal branch?
General sensory fibers from V2
Postganglionic parasympathetic fibers from pterygopalatine ganglion
Postganglionic sympathetic fibers from deep petrosal
What types of nerve fibers are associated with the deep petrosal nerve?
Postganglionic sympathetic fibers from internal carotid plexus
What are the 4 main branches arising from the main trunk of the maxillary nerve?
- Orbital branches
- Zygomatic branch
- Superior alveolar nerves (posterior, middle, and anterior)
- Infraorbital nerve
Which air sinuses do the orbital branches of the maxillary division supply?
Ethmoidal, sphenoidal, and frontal air sinuses
What are the 3 fiber types of the orbital branches of the maxillary division?
General sensory from V2 (maxillary nerve)
Postganglionic parasympth fibers from pterygopalatine ganglion
Postgang sympth from deep petrosal nerve
What are the two branches that split off of the zygomatic branch (branch of the maxillary nerve), and what areas do they supply?
Zygomaticofacial (sensory to zygomatic region of face)
Zygomaticotemporal (sensory to temporal region of face)
Describe the parasympathetic fibers in the zygomatic branch of the maxillary nerve.
Receives postganglionic parasympathetic fibers from pterygopalatine ganglion, and hands them off to the lacrimal nerve of V1
-therefore, zygomaticofacial and zygomaticotemporal do NOT have parasympathetic fibers
What are the 3 superior alveolar nerves and where specifically do they branch off of?
The posterior, middle and anterior
Posterior branches from main trunk of maxillary
The anterior and middle branches from the infraorbital nerve
What does the posterior superior alveolar nerve supply (branch of maxillary nerve)?
Supplies mucous membrane of maxillary sinuses and upper molar teeth
What does the middle superior alveolar nerve supply (branch of infraorbital nerve of maxillary)?
Supplies the mucous membrane of the maxillary sinuses and the upper premolar teeth
What does the anterior superior alveolar nerve supply (branch of the infraorbital nerve of maxillary)?
Supplies the mucous membrane of maxillary sinuses and the upper 3 anterior teeth
What is the dental plexus?
A plexus of the anterior, middle, and posterior alveolar nerves innervating the upper teeth
What are the fiber types contained in the superior alveolar nerves (hint: it’s the same for all 3 divisions)?
- General sensory fibers from V2
- Postganglionic parasympathetic fibers from pterygopalatine ganglion
- Postganglionic sympathetic fibers from the deep petrosal nerves
What is the terminal branch of the maxillary division?
The infraorbital nerve
What is supplied by the infraorbital nerve?
Supplies lower eyelid, side of the nose, upper lip, front of the cheek, and the nasal vestibule
What are the fiber types contained within the infraorbital nerve?
-General sensory fibers from V2
-Postgang Sympth fibers from deep petrosal nerve
(only 2! No parasympth innervation)
What are the 3 branches of the maxillary division of the trigeminal that innervate the skin? What is the consequence of these fibers regarding the fiber types they contain?
The zygomaticofacial branch
The zygomaticotemporal branch
The infraorbital nerve
- all 3 do NOT contain parasympathetic fibers, as parasympathetic fibers are not located in the skin
What branch of the trigeminal receives the entire motor root of the trigeminal?
The mandibular division of trigeminal (V3), though still majority sensory fibers in its content
Through what foramen does the mandibular division leave the skull? Which fossa does it enter? Which parasympathetic ganglion is it then connected to?
Leaves skull through foramen ovale, enters the infratemporal fossa, and joins with the otic ganglion
What muscles are supplied by the motor branch of the mandibular branch?
- Muscles of mastication
- Mylohyoid and anterior belly of the digastric muscle
- Tensor of the palate
- Tensor tympani
Which nerve carries the motor nerve to mylohyoid and anterior belly of digastric? When does it split off?
The inferior alveolar branch of the maxillary branch carries the nerve to the anterior belly of digastric and mylohyoid, and breaks off just before this nerve enters the mandibular foramen
What are the branches of the main trunk of the mandibular nerve?
Meningeal branch
Medial pterygoid nerve
What is the meningeal nerve a branch of, where does it enter the skull, and with what artery?
Meningeal nerve is a branch of the main trunk of the mandibular division, enters the skull through the foramen spinosum along with middle meningeal artery
What is supplied by the meningeal branch of the mandibular division?
Supplies part of the dura of middle cranial fossa and mastoid air cells
What is supplied by the medial pterygoid nerve? What is it a branch of?
Medial pterygoid nerve is a branch of the mandibular division
Supplies the medial pterygoid muscle
What 2 branches are given off by the medial pterygoid nerve of the mandibular division?
Gives off the nerve to the tensor tympani
Gives off the nerve to the tensor of the palate
What are the 4 branches of the anterior division of the mandibular branch? What type of fibers are these primarily?
Masseteric nerve
Deep temporal nerve (anterior and posterior)
Lateral pterygoid nerve
Long buccal nerve
Primarily motor fibers
What is the masseteric nerve a branch of, what is the muscle that it supplies, and where does it provide sensory fibers?
Masseteric nerve is a branch of the anterior division of the mandibular division V3 of trigeminal
It supplies the masseter muscle
Gives off a sensory twig to the temporomandibular joint
What are the deep temporal nerves (anterior and posterior) a branch of, what is the muscle that it supplies, and where does it provide sensory fibers?
Deep temporal nerve is a branch of the anterior division of the mandibular division V3 of trigeminal
Supplies the temporalis muscle
Gives a sensory twig to temporomandibular joint
What is the lateral pterygoid nerve a branch of, and what muscle does it supply?
Lateral pterygoid is a branch of the anterior division of mandibular and it supplies the lateral pterygoid muscle
What is the long buccal nerve a branch of, what type of fibers are contained in it, and where do those fibers go to/supply?
The long buccal nerve is a branch of the anterior division of the mandibular branch (V3) and it descends over the buccinator muscle and supplies the mucous membrane of the cheek and gums (molar area) and the skin of the overlying cheek
Is a purely sensory fiber
What are the branches of the posterior division of the mandibular branch V3?
- Auriculotemporal nerve
- Inferior alveolar nerve
- Lingual nerve
Largely sensory fibers except for the mylohyoid nerve
Describe the parasympathetic pathway through the auriculotemporal nerve.
The auriculotemporal nerve is a branch of the mandibular division of the trigeminal nerve, so it picks up parasympathetic fibers from the otic ganglion. The auriculotemporal nerve picks up nerve fibers from the otic ganglion to deliver them to the parotid gland
Describe the parasympathetic pathway starting with the glossopharyngeal nerve***
Glossopharyngeal nerve has parasympathetic fibers that get sent through the tympanic branch, which passes them off to the lesser petrosal nerve (carries preganglionic para fibers), which passes them off to the otic ganglion. Then, the auriculotemporal nerve of the posterior division of the mandibular nerve of the trigeminal passes it off to the parotid gland.
What nerve is the main supply of the temporomandibular joint (of sensory fibers, e.g. when there is TMJ pain)***? What are the smaller sensory supplies?
The main supply is from the auriculotemporal nerve of the posterior division of the mandibular branch
Receives small sensory twigs from the masseteric nerve and the deep temporal nerve (which are both branches of the anterior division of the mandibular branch)
What is the only branch of the posterior division that contains motor fibers?
Only the inferior alveolar nerve which contains the mylohyoid branch has motor fibers to the mylohyoid muscle (and the anterior belly of the digastric)
What are the two terminal branches of the inferior alveolar nerve after passing through the mandibular canal? What does it supply?
The two terminal branches are the mental nerve and the incisive nerve. Generally supplies the molar and second premolar teeth
- Mental nerve - supplies skin of lower lip and chin, mucous membrane of lower lip, and some of gingiva
- Incisive nerve - supplies the first premolar, lower canine, and incisor teeth
What sensory fibers do the lingual nerve supply?
The lingual nerve has general sensory for the anterior 2/3 of the tongue, the lingual gingiva, and the floor of the mouth
What nerve (and from which cranial nerve is it a branch of) joins with the lingual nerve? What is the purpose of this?***
The lingual nerve joins with the chorda tympani of the facial nerve (CN VII)
- Chorda tympani has pregang parasympth fibers AND taste fibers for the anterior 2/3 of the tongue (fungiform papillae)
- The lingual nerve itself is a purely sensory nerve!! but picks up pregang para sympth and taste fibers from chorda tympani
What is the path of the chorda tympani?
The chorda tympani leaves the facial nerve
- runs along lateral wall of tympanic cavity
- emerges through petrotympanic fissure where it joins lingual nerve
Where do the chorda tympani and lingual nerve join?
Join in the petrotympanic fissure
Describe the course of the lingual nerve
It is closely relate to the 3rd molar tooth
When it crosses the floor of the mouth, it is closely related to the submandibular tract
Where do the preganglionic parasympathetic fibers from the chorda tympani depart from the lingual nerve, and where do they synapse?
They depart from the lingual nerve at the submandibular ganglion and synapse in the submandibular ganglion
Where do the postganglionic parasympathetic fibers from the submandibular ganglion originate from, and where do they go to?
They originate from the chorda tympani which travels with the lingual nerve of the posterior division of the mandibular nerve V3.
They go to the submandibular gland or join the lingual nerve via communicating fibers to end in sublingual and lingual salivary glands (salivary glands are parasympathetically innervated)
What do lesions of the trigeminal nerve result in?
Loss of facial sensation
Deviation of the jaw to side of lesion due to weakness of muscles of masication
Trigeminal neuralgia (which most commonly affects maxillary division)
