Trigeminal Nerve 2

Question 1

Where does the mandibular branch of the trigeminal nerve travel before it branches

Answer 1

Passes through the foramen ovale into the infratemporal fossa where it branches

Question 2

What are the anterior, lateral and medial boundaries of the infratemporal fossa

Answer 2

Anterior - posterior aspect of maxilla
Lateral - ramus of the mandible
Medial - lateral pterygoid plate of sphenoid bone

Question 3

What are the posterior, superior and inferior boundaries of the infratemporal fossa

Answer 3

Posterior - tympanic plate, mastoid and styloid processes
Superior - infratemporal crest of sphenoid bone
Inferior - angle of the mandible

Question 4

What supplies the skin over the angle of the mandible

Answer 4

The cervical plexus with the great auricular nerve - C2,3

Question 5

What are the main branches of CN Vc

Answer 5

Auriculotemporal
Buccal
Mental
Lingual
Muscular

Question 6

What nerves of CN Vc branch from the main trunk

Answer 6

Meningeal branch
Branch to tensor tympani
Branch to tensor veil palatini
Nerve to medial pterygoid

Question 7

What nerves of CN Vc branch from the anterior trunk

Answer 7

Deep temporal nerves
Nerve to lateral pterygoid
Buccal nerve
Masseteric nerve

Question 8

What nerves of CN Vc branch from the posterior trunk

Answer 8

Auriculotemporal nerve
Lingual nerve
Inferior alveolar nerve

Question 9

Describe the modalities of the nerves branching from the main trunk

Answer 9

All motor apart from the meningeal nerve which is sensory to the dura mater

Question 10

Describe the modalities of the nerves branching from the anterior trunk

Answer 10

All motor apart from the buccal nerve which is sensory

Question 11

Describe the modalities of the nerves branching from the posterior trunk

Answer 11

All sensory apart from the inferior alveolar nerve that is mixed
Sensory component goes inside the mandibular bone, motor component comes off as the nerve to mylohyoid

Question 12

What does CN Vc supply

Answer 12

General sensation to the floor of the mouth, lower teeth and gums
General sensation to the anterior 2/3rd of the tongue via the lingual nerve
Temple
Auricle
Chin
Cheek - posteriorly and laterally

Question 13

What happens if a patient experiences injury to CN Vc

Answer 13

They will experience trigeminal neuralgia - terrible pain

Usually in Vc but can happen occasionally in Vb

Question 14

Describe the general sensory supply to the oral cavity from CN Vc

Answer 14

Buccal nerve to cheek and lateral gum
Inferior alveolar nerve and its branch, the incisive nerve to lower teeth
Inferior alveolar nerve to skin of chin and lower lip as the mental nerve

Question 15

What does the nerve to mylohyoid supply

Answer 15

Motor to the mylohyoid and the anterior belly of digastric

Question 16

Which nerves supply the mandibular teeth

Answer 16

Main trunk of inferior alveolar nerve supplies posterior teeth
Incisive branch of inferior alveolar nerve supplies anterior teeth

Question 17

Which nerves supply the mandibular gingivae

Answer 17

Lingual nerve
Buccal nerve
Mental nerve from inferior alveolar nerve

Question 18

What nerves supply the anterior 2/3rds of the tongue

Answer 18

General sensation via the lingual nerve
Special sensation (taste) supplied via a branch in the facial nerve called the chorda tympani

Question 19

Which muscles does CN Vc supply

Answer 19

Muscles of mastication
Tensor tympani
Tensor palatini
Mylohyoid
Anterior belly of digastric

Question 20

How is CN Vc tested clinically and why is this done

Answer 20

Jaw jerk reflex
Sensory info is passed through the trigeminal into the mesencephalic nucleus which deals with proprioception
From here it connects to the motor nucleus in the pons which will send info out to deal with the reflex

Question 21

What causes shingles

Answer 21

Reactivation of the varicella zoster virus in the trigeminal ganglion

Question 22

What are the signs of shingles

Answer 22

Erythematous, vesicular, crusting rash with burning sensation
Hutchinson’s sign - cutaneous involvement of the tip of the nose
Conjunctivitis, keratitis and uveitis