trigeminal nerve Flashcards
How is trigeminal neuralgia treated?
Trigeminal neuralgia is treated with antiseizure meds
Identify nerve branch of trigeminal nerve and do a nerve block to prevent for procedures
What are the branches of the trigeminal nerve?
Opthalmic is the front part
Maxillary (most commonly affected by trigeminal neuralgia)
Mandibular nerve (learn to do a good block)
How does location of bundles of cell bodies of nerves affect what they are called?
Nuclei if they happen to be in central nervous system if they are outside the central nervous system they are called ganglia
What are the nuclei of the trigeminal nerve?
3 sensory nuclei + 1 motor nucleus
What are the functions of trigeminal nerve?
Sensory to face and scalp
Motor to muscles of mastication, tensor tympani, tensor veli pallatini, mylohyoid, and the anterior belly of the digastric
Where do the sensory roots originate from?
The 3 sensory nuclei:
V1, V2, and V3
Where does the motor root originate from?
The motor nucleus.
Where does V1 exit the skull?
Superior orbital fissure
Where does V2 exit the skull?
Lateral wall of the cavernous sinus -> Foramen rotundum
Where does V3 exit the skull?
Mandibular nerve through foramen ovale
What are the branches of the opthalmic nerve?
Lacrimal
Frontal
Nasociliary
Gives off these branches just before it reaches the superior orbital fissure
What does the opthalmic nerve do?
Sensory innervation to:
• The eye (including cornea and conjunctiva) • Skin of the upper eyelid, forehead, back of the nose, the nasal and paranasal mucosa.
Parasympathetic fibbers to:
• The lacrimal gland
What does the lacrimal nerve do?
It is the smallest branch and enters the orbit through the superior orbital fissure and moves forward through the lateral wall of the orbit and travels through the lacrimal gland to supply the conjunctiva and the skin of the lateral part of the upper lid.
What does the frontal nerve branch into?
Largest branch of opthalmic nerve, enters through superior orbital fissure , medial to lacrimal nerve, and branches into supraorbital (larger and leaves orbit through supraorbital foramen) and supratrochlear (skin and conjunctiva of the upper eyelid)
What does the nasocilliary branch do?
Connects with nasocilliary ganglion and supplies the iris and cornea
What are the branches of the maxillary nerve?
Sensory
Branches: • Pterygopalatine fossa – Zygomatic nerve – Infraorbital nerve – Nasopalatine nerve – Posterior superior alveolar nerve – Greater and lesser palatine nerves – Pharyngeal nerve • Infraorbital canal – Middle superior alveolar nerve – Anterior superior alveolar nerve
What are the main branches of the maxillary nerve?
Zygomatic nerve: Branches off the maxillary nerve close to lateral wall of orbit. Branches ito zyg
Infraorbtal nerve
What are the main branches of the maxillary nerve?
Zygomatic nerve: Branches off the maxillary nerve close to lateral wall of orbit. Branches ito zyg
Infraorbtal nerve
How should maxillary teeth be blocked?
Inject into root by putting needle through the alveolar bone 12mm up the tooth’s shape and numbing the root
What is the function of the mandibular nerve?
Mandibular nerve is the largest division of the trigeminal nerve
Function is mixed:
Sensory:
– Mandibular teeth and gingivae – The skin of temporal region – Lower lip and lower face – Mucosa of the anterior 2/3 tongue and floor of the oral cavity
Motor:
– Muscles of mastication
What are the branches of the mandibular nerve?
3 branches, meningeal, anterior and posterior
Why is buccal nerve sometimes blocked?
Buccal block to prevent sensory innervation from the buccal nerve of mandibular nerve.
What nerve does the posterior trunk of the mandibular nerve communicate with?
Communicates with facial nerve
Which of the opthalmic nerve branches is most lateral and which is most medial? Which is largest and which is smallest?
Lacrimal nerve is most lateral and is smallest
Frontal nerve is largest and medial to the lacrimal nerve but lateral to the nasocilliary nerve
Nasocilliary nerve is most medial and not as big as the frontal nerve nor as small as the lacrimal gland.
What is the function of the maxillary nerve?
It is sensory
What are the branches of the maxillary nerve that go through the pterygopalatine fossa?
Zygomatic nerve (IMPORTANT)
Infraorbital nerve (IMPORTANT)
Nasopalatine nerve
Posterior superior alveolar nerve
Greater and Lesser palatine nerves
Pharyngeal nerve
What are the branches of the maxillary nerve that go to the infraorbital canal?
Middle superior alveolar nerve
Anterior superior alveolar nerve
What are the branches of the zygomatic nerve?
Branches off the maxillary nerve close to the lateral wall of the orbit then branches into:
Zygomaticotemporal nerve (innervates the temple)
Zygomaticofacial nerve (Innervates the prominence of the cheek)
Where does the infraorbital nerve go to emerge on the face?
Through the infraorbital foramen
What does the mandibular branch of the trigeminal nerve do?
It is the largest division of the trigeminal nerve and has mixed sensory and motor function.
What are the sensory functions of the mandibular nerve?
Mandibular teeth and gingivae
The skin of the temporal region
Lower lip and lower face
Mucosa of the anterior 2/3rds of the tongue and the floor of the oral cavity
What are the motor functions of the mandibular nerve?
Muscles of mastication
Where does the mandibular nerve leave the brain through?
The foramen ovale; 4cm deep just anterior to the condyle and passes between tensor veli palatini and lateral pterygoid
What are the branches of the mandibular nerve?
Meningeal
Anterior
Posterior
What is the function of the anterior branch of the mandibular nerve?
Motor to muscles of mastication
Forms the buccal nerve which is sensory (Buccal nerve of mandibular nerve is the ideal nomenclature) to the cheek
What are the functions of the posterior branch of the mandibular nerve? (list branches and/or muscle innervations)
Sensory:
Branches into auriculotemporal lingual, and inferior alveolar nerve
Motor:
Myelohyoid and anterior belly of digastric muscles
What are the nerve branches of the anterior trunk that go to the muscles of mastication?
Masseter nerve (Masseter muscle with articular branches to the TMJ)
Deep temporal nerve (Anterior and posterior branches to the temporalis muscle)
Lateral pterygoid nerve (To lateral pterygoid muscle)
Where does the buccal nerve of the mandibular nerve go after branching off the anterior trunk of the mandibular nerve?
Goes through the two heads of lateral pterygoid and innervates the buccal mucosa + posterior buccal gingivae of 2nd and 3rd lower molars.
What are the branches of the posterior trunk of the mandibular nerve?
3 sensory branches: Auriculotemporal, lingual, and inferior alveolar nerve
Motor branches: Myelohyoid, and anterior belly of digastric
What is the function of the auriculotemporal nerve?
It is a branch of the posterior trunk of the mandibular nerve that is sensory and parasympathetic.
What is the route of the auriculotemporal nerve?
Passes behind the TMJ and upper parts of the parotid gland (communicates with facial nerve) before it branches into a cutaneous branch (tragus and posterior part of the temple) and a parasympathetic root that goes to the parotid gland
What is the function of the lingual division of the posterior trunk of the mandibular nerve?
Sensory:
Mucosa of anterior 2/3rds of the tongue
Floor of the mouth
Mandibular lingual gingivae
What joins the lingual division of the posterior trunk of the mandibular nerve?
Joined by chorda tympani from the facial nerve
What is the function of the inferior alveolar nerve?
It is sensory
What is the route of the inferior alveolar nerve after it branches away from the posterior trunk of the mandibular nerve?
It enters the mandible via the mandibular foramen (accompanied by inferior alveolar artery), and branches into the mental nerve and a main branch.
What are the branches of the inferior alveolar nerve and what do they do?
Mental nerve: Exits the mental foramen and provides innervation to skin of the lower lip, buccal gingiva of lower 6 to 6 and labial mucosa
Main branch: Supplies lower teeth and crosses the midline
