Trigeminal Neuroanatomy

Question 1

What is CN V

Answer 1

Mixed nerve
V1/V2 = sensory only
V3 = sensory and motor (muscles of mastication)

Question 2

What is V1

Answer 2

Opthalamic division (through superior orbital fissure)

3 branches - frontal, nasociliary, lacrimal

Question 3

What is V2

Answer 3

Maxillary division (through foramen rotundum, enters pterygopalatine fossa)

5 branches - nasopalatine, greater palatine, PSA, infraorbital (ASA + MSA), zygomatic nerves

Question 4

What is V3

Answer 4

Mandibular division (through foramen ovale)

3 sections - undivided (muscular), anterior trunk (Long Buccal + motor), posterior trunk (IA, lingual and auriculotemporal nerve)

5 branches - long buccal, motor to mm of mastication, auriculotemporal, lingual, IAN (mylohyoid, mental and incisive)

Question 5

What is CN VII

Answer 5

Facial nerve - mixed nerve
- motor to muscles of facial expression
- sensory to anterior 2/3 tongue (taste)

Question 6

What is the path of the facial nerve

Answer 6

1) Through Internal Acoustic Meatus (temporal bond) –> branches = chorda tympani n. and greater petrosal n.
2) Exits skull via Stylomastoid Foramen (temporal bone)
3) Enters Parotid Gland –> branches = temporal n., zygomatic n., buccal n., mandibular n., cervical n.

Question 7

Branches of facial nerve in parotid gland

Answer 7

Temporal
Zygomatic
Buccal
Mandibular
Cervical

Question 8

What does external carotid a terminate as

Answer 8

Maxillary and superficial temporal

Question 9

Where does maxillary artery run?

Answer 9

Begins within Parotid Gland at neck of condyle (mandible) –> runs between mandible and sphenomandibular ligament (lingula) –> enters infratemporal fossa –> gives off 4 branches –> enters Pterygopalatine fossa –> gives off 4 branches

Question 10

What does maxillary artery branch into within infratemporal fossa

Answer 10

1) Middle Meningeal a.
2) Inferior Alveolar a. –> branches in Mental a. and Incisive a. and Mylohyoid a.
3) Branches to mm of mastication (Temporalis, Pterygoids, Meesseteric)
4) Buccal a.

Question 11

What does maxillary artery branch into within pterygopalatine fossa

Answer 11

1) PSA a.
2) Infraorbital a. –> branches into ASA a.
3) Greater Palatine a.
4) Sphenopalatine a. –> branches into Nasopalatine a.

Question 12

Pterygoid plexus

Answer 12

-VENOUS plexus of small anastomosing vessels
-Located around pterygoid muscles and surrounding maxillary a. and infratemporal fossa
**Protects the maxillary artery from being compressed during mandibular movement
**Associated with Hematoma and spread of infection during INCORRECTLY administered PSA injections