Trigeminal Nerve Anatomy

Question 1

What are the different branches of the trigeminal nerve?

Answer 1

V1 - ophthalmic branch (sensory)
V2 - maxillary branch (sensory)
V3 - mandibular branch (sensory and motor)

Question 2

Where do the branches of the trigeminal exit the skull?

Answer 2

V1 - supraorbital notch
V2 - infraorbital foramen
V3 - mental foramen

Question 3

What level of the brain does the trigeminal nerve emerge from?

Answer 3

• mid pons

Question 4

Where is the motor nucleus of the trigeminal?

Answer 4

• mid pons

Question 5

What are the 3 trigeminal sensory nuclei and where are they located?

Answer 5

• 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

Question 6

Where does the trigeminal ganglion lie?

Answer 6

• meckels cave

Question 7

Where does the trigeminal ganglion exit meckels cave?

Answer 7

• ophthalmic (V1) via the superior orbital fissure
• maxillary (V2) via the foramen rotundum
• mandibular (V3) via the foramen ovale

Question 8

What are the three main branches of the ophthalmic nerve?

Answer 8

• frontal
• lacrimal
• nasocilliary

Question 9

What does the ophthalmic nerve innervate?

Answer 9

• forehead
• cornea
• top of nose etc

Question 10

Where does the maxillary division of the trigeminal branch?

Answer 10

• pterygopalatine fossa

Question 11

What are the three main branches of the maxillary nerve?

Answer 11

• zygomatic
• infraorbital
• pterygopalatine ganglion

Question 12

Where does the superior alveolar nerve branch from?

Answer 12

• infraorbital branch of CN V2

Question 13

Describe the course of the nasopalatine nerve.

Answer 13

• 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

Question 14

What does the nasopalatine nerve innervate?

Answer 14

• supplies palatal structures around the 6 anterior maxillary teeth

Question 15

Describe the course of the greater palatine nerve.

Answer 15

• 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

Question 16

What does the greater palatine nerve innervate?

Answer 16

• posterior hard palate

Question 17

Describe the course of the lesser palatine nerve.

Answer 17

• 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

Question 18

What does the lesser palatine nerve innervate?

Answer 18

• soft palate

Question 19

Describe the course of the posterior superior alveolar nerve.

Answer 19

• • 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

Question 20

Describe the course of the middle superior alveolar nerve.

Answer 20

• 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

Question 21

Describe the course of the anterior superior alveolar nerve.

Answer 21

• 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

Question 22

What do the superior alveolar nerves innervate?

Answer 22

• 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

Question 23

What are the three trunks of the mandibular division?

Answer 23

• main trunk (1 motor, 1 sensory)
• anterior (mostly motor)
• posterior (mostly sensory)

Question 24

Describe the main trunk of CN V3.

Answer 24

• 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

Question 25

What are the branches of the anterior trunk of CN V3?

Answer 25

``` Motor - deep temporal nerves - nerve to lateral pterygoid - masseteric nerve Sensory - buccal nerve ```

Question 26

What are the branches of the posterior trunk of CN V3?

Answer 26

``` Sensory - lingual - auriculotemporal Sensory and motor - inferior alveolar nerve ```

Question 27

What does the buccal nerve innervate?

Answer 27

- sensory - buccal gingiva of upper molars - cheek mucosa

Question 28

What does the lingual nerve supply?

Answer 28

- sensory - anterior 2/3 of the tongue - floor of mouth - lingual gingiva

Question 29

Describe the course of the inferior alveolar nerve.

Answer 29

- 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

Question 30

What does the inferior alveolar nerve innervate?

Answer 30

- sensory - mandibular teeth - associated buccal gingiva

Question 31

What does the nerve to the mylohyoid innervate?

Answer 31

- motor - mylohyoid muscle - anterior belly of the digastric muscle

Question 32

What does the incisive nerve innervate?

Answer 32

- sensory | - canines and incisors of the mandibular arch

Question 33

What does the mental nerve innervate?

Answer 33

- sensory - chin - lower lip - buccal gingiva of teh mandibular anteriors and premolars

Question 34

What does the auriculotemporal nerve innervate?

Answer 34

- sensory - TMJ - elements of the ear

Question 35

What bones make up the hard palate?

Answer 35

- maxilla | - palatine

Question 36

What is the lingula?

Answer 36

- bony triangular process next to the mandibular foramen

Question 37

What divides the tongue into the anterior 2/3 and the posterior 1/3?

Answer 37

- terminal sulcus

Question 38

What nerve supplies general and special sensory to the posterior 1/3 of the tongue?

Answer 38

- glossopharyngeal (CN IX)

Question 39

What nerve supplies general sensory to the anterior 2/3 of the tongue?

Answer 39

- lingual nerve

Question 40

What nerve supplies the tongue muscle?

Answer 40

- hypoglossal (CN XII) supplies all except for the palatoglossal muscle which is innervated by the vagus nerve (CN X)

Question 41

What relationship does the chorda tympani nerve have with the trigeminal nerve?

Answer 41

- branch of the facial nerve - supplies special sensation to the anterior 2/3 of the tongue - joins the lingual nerve as a "piggyback"