Trigeminal Nerve Anatomy Flashcards
What are the different branches of the trigeminal nerve?
V1 - ophthalmic branch (sensory)
V2 - maxillary branch (sensory)
V3 - mandibular branch (sensory and motor)
Where do the branches of the trigeminal exit the skull?
V1 - supraorbital notch
V2 - infraorbital foramen
V3 - mental foramen
What level of the brain does the trigeminal nerve emerge from?
- mid pons
Where is the motor nucleus of the trigeminal?
- mid pons
What are the 3 trigeminal sensory nuclei and where are they located?
- mesencephalic nucleus, proprioception, located in the mid brain
- chief sensory, discriminative touch, located in the pons
- spinal nucleus, pain and temperature, located in the medulla
Where does the trigeminal ganglion lie?
- meckels cave
Where does the trigeminal ganglion exit meckels cave?
- ophthalmic (V1) via the superior orbital fissure
- maxillary (V2) via the foramen rotundum
- mandibular (V3) via the foramen ovale
What are the three main branches of the ophthalmic nerve?
- frontal
- lacrimal
- nasocilliary
What does the ophthalmic nerve innervate?
- forehead
- cornea
- top of nose etc
Where does the maxillary division of the trigeminal branch?
- pterygopalatine fossa
What are the three main branches of the maxillary nerve?
- zygomatic
- infraorbital
- pterygopalatine ganglion
Where does the superior alveolar nerve branch from?
- infraorbital branch of CN V2
Describe the course of the nasopalatine nerve.
- part of CN V2, therefore leaves meckels cave via foramen rotundum
- branches at the pterygopalatine fossa into the pterygopalatine ganglion
- leaves the pterygopalatine fossa via the sphenopalatine foramen
- passes via the incisive canal to reach the anterior hard palate
What does the nasopalatine nerve innervate?
- supplies palatal structures around the 6 anterior maxillary teeth
Describe the course of the greater palatine nerve.
- part of CN V2, therefore leaves meckels cave via foramen rotundum
- branches at the pterygopalatine fossa into the pterygopalatine ganglion
- leaves the pterygopalantine fossa via the palatine canal
- enters the oral cavity via greater palatine foramen
What does the greater palatine nerve innervate?
- posterior hard palate
Describe the course of the lesser palatine nerve.
- part of CN V2, therefore leaves meckels cave via foramen rotundum
- branches at the pterygopalatine fossa into the pterygopalatine ganglion
- leaves the pterygopalatien fossa via the palatine canal
- enters the oral cavity via lesser palatine foramen
What does the lesser palatine nerve innervate?
- soft palate
Describe the course of the posterior superior alveolar nerve.
- part of CN V2, therefore leaves meckels cave via the foramen rotundum
- branches at the pterygopalatine fossa into the three different superior alveolar branches
- the posterior superior alveolar nerve leaves the pterygopalatine fossa via the pterygopalatine fissure
Describe the course of the middle superior alveolar nerve.
- part of CN V2, therefore leaves meckels cave via the foramen rotundum
- branches at the pterygopalatine fossa into the three different superior alveolar branches
- the middle superior alveolar nerve leaves the pterygopalatine fossa via the inferior orbital fissure
Describe the course of the anterior superior alveolar nerve.
- part of CN V2, therefore leaves meckels cave via the foramen rotundum
- branches at the pterygopalatine fossa into the three different superior alveolar branches
- the anterior superior alveolar nerve leaves the pterygopalatine fossa via the inferior orbital fissure
What do the superior alveolar nerves innervate?
- maxillary teeth and the associated buccal gingiva
- posterior = molars
- middle = premolars
- anterior = anteriors
- the nerves loop back to form the dental plexus
- the nerves enter the tooth pulp via the apical foramen
What are the three trunks of the mandibular division?
- main trunk (1 motor, 1 sensory)
- anterior (mostly motor)
- posterior (mostly sensory)
Describe the main trunk of CN V3.
- 2 branches
- sensory branch known as nervus spinosus or the meningeal nerve, this innervates the dura
- motor branch known as the nerve to the medial pterygoid and some muscles in the middle ear
What are the branches of the anterior trunk of CN V3?
Motor - deep temporal nerves - nerve to lateral pterygoid - masseteric nerve Sensory - buccal nerve
What are the branches of the posterior trunk of CN V3?
Sensory - lingual - auriculotemporal Sensory and motor - inferior alveolar nerve
What does the buccal nerve innervate?
- sensory
- buccal gingiva of upper molars
- cheek mucosa
What does the lingual nerve supply?
- sensory
- anterior 2/3 of the tongue
- floor of mouth
- lingual gingiva
Describe the course of the inferior alveolar nerve.
- part of CN V3, therefore leaves meckels cave via the foramen ovale
- enters the infratemporal fossa where it branches into the posterior trunk of CN V3
- before CN V3 enters the mandible it branches to give the lingual, IAN and auricuoltemporal
- the IAN enters the mandible at the mandibular foramen, just before this the nerve to the mylohyoid branches off
- the IAN then branches into the mental and incisive nerve
- the incisive nerve does not leave the mandible
- the mental nerve exits the mandible via the mental foramen
What does the inferior alveolar nerve innervate?
- sensory
- mandibular teeth
- associated buccal gingiva
What does the nerve to the mylohyoid innervate?
- motor
- mylohyoid muscle
- anterior belly of the digastric muscle
What does the incisive nerve innervate?
- sensory
- canines and incisors of the mandibular arch
What does the mental nerve innervate?
- sensory
- chin
- lower lip
- buccal gingiva of teh mandibular anteriors and premolars
What does the auriculotemporal nerve innervate?
- sensory
- TMJ
- elements of the ear
What bones make up the hard palate?
- maxilla
- palatine
What is the lingula?
- bony triangular process next to the mandibular foramen
What divides the tongue into the anterior 2/3 and the posterior 1/3?
- terminal sulcus
What nerve supplies general and special sensory to the posterior 1/3 of the tongue?
- glossopharyngeal (CN IX)
What nerve supplies general sensory to the anterior 2/3 of the tongue?
- lingual nerve
What nerve supplies the tongue muscle?
- hypoglossal (CN XII) supplies all except for the palatoglossal muscle which is innervated by the vagus nerve (CN X)
What relationship does the chorda tympani nerve have with the trigeminal nerve?
- branch of the facial nerve
- supplies special sensation to the anterior 2/3 of the tongue
- joins the lingual nerve as a “piggyback”
