Trigeminal

Question 1

What base of skull foramina does CNV1 pass through?

Answer 1

Superior orbital fissure

Question 2

What base of skull foramina does CNV2 pass through?

Answer 2

Foramen rotundum

Question 3

What base of skull foramina does CNV3 pass through?

Answer 3

Foramen ovale

Question 4

What type of information is carried on CNV1?

Answer 4

Sensory

Question 5

What type of information is carried on CNV2?

Answer 5

Sensory

Question 6

What type of information is carried on CNV3?

Answer 6

Sensory and motor

Question 7

What are the sensory functions of CNV?

Answer 7

Somatosensation of the face, mouth, anterior 2/3rds of tongue, sinuses and supratentorial meninges / proprioception associated with chewing

Question 8

CNV supplies the motor control to which muscles?

Answer 8

Muscles of mastication, tensor tympani, tensor veli palatini, mylohyoid, anterior belly of digastric

Question 9

Where does the trigeminal nerve connect to the CNS?

Answer 9

At the pons (laterally, midway between midbrain and medulla)

Question 10

Once the trigeminal nerve has connected with the CNS at the pons, describe its intracranial path?

Answer 10

Travels inferior to the edge of the tentorium cerebelli between the posterior and middle cranial fossa

Question 11

Describe the extracranial path of the sensory axons of CNV?

Answer 11

Course from the superficial and deep structures of the face to their respective cranial formina

Question 12

Describe the extracranial path of the motor axons of CNV?

Answer 12

Course from the foramen ovale towards the skeletal muscle they supply

Question 13

What are the specific regions of the face supplies by CNV1, V2 and V3?

Answer 13

V1 = ophthalmic, V2 = maxillary, V3 = mandibular

Question 14

What are some areas of the face which are supplied by CNV1?

Answer 14

Upper eyelid, cornea, conjunctiva, skin of the root/bridge/tip of the nose

Question 15

Which specific part of CNV is responsible for the afferent limb of the corneal reflex?

Answer 15

CNV1

Question 16

What are some areas of the face which are supplied by CNV2?

Answer 16

Lower eyelid, maxilla, ala of the nose, upper lip

Question 17

What are some areas of the face which are supplied by CNV3?

Answer 17

Skin over the mandible and TMJ

Question 18

What is the sensory supply to the angle of the mandible?

Answer 18

C2, 3 - great auricular nerve

Question 19

Where are trigeminal sensory cell bodies located? Where do their projections terminate?

Answer 19

In the trigeminal ganglion / the trigeminal nucleus

Question 20

Where is the trigeminal sensory ganglion found?

Answer 20

In the middle cranial fossa

Question 21

Describe the sensory nucleus of the trigeminal nerve?

Answer 21

Forms a long column of neurones which stretch from the midbrain down to the upper two segments of the cervical spinal cord

Question 22

Describe the function of the mesencephalic nucleus (part of the sensory nucleus of the trigeminal nerve)?

Answer 22

Proprioception information from the muscles of mastication

Question 23

Describe the function of the pontine trigeminal nucleus (part of the sensory nucleus of the trigeminal nerve)?

Answer 23

Touch and vibration

Question 24

Describe the function of the spinal nucleus (part of the sensory nucleus of the trigeminal nerve)?

Answer 24

Pain and temperature

Question 25

What is unusual about the mesencephalic nucleus (part of the sensory nucleus of the trigeminal nerve)?

Answer 25

It is the only sensory nucleus within the CNS

Question 26

What is the function of the ventral trigeminothalamic tract?

Answer 26

Passes the sensory fibres of CNV through the thalamus and into the cortex

Question 27

The motor neurones of CNV originate where?

Answer 27

In the trigeminal motor nucleus

Question 28

Describe the innervation of the LMNs of CNV?

Answer 28

They receive bilateral innervation from the UMNs

Question 29

What are the three pairs of jaw closing muscles supplied by CNV3?

Answer 29

Masseter, temporalis and medial pterygoid

Question 30

What is the one pair of jaw closing muscles supplied by CNV3?

Answer 30

Lateral pterygoid

Question 31

What does the mylohyoid muscle do?

Answer 31

Opens the mouth for swallowing and speech

Question 32

What does the anterior belly of digastric muscle do?

Answer 32

Also helps to open the mouth

Question 33

What does the tensor veli palatini muscle do?

Answer 33

Tenses the palate during swallowing

Question 34

What does the tensor tympani muscle do?

Answer 34

Tenses the tympanic membrane of the ear to reduce vibrations

Question 35

How is the sensory function of CNV tested?

Answer 35

By asking the patient to close their eyes and touch their skin in each region - ask the patient to tell you when they can feel something and compare the two sides

Question 36

How can the motor function of CNV be tested?

Answer 36

Palpate the strength of contraction of the masseter and temporalis muscles by asking the patient to clench their teeth / ask the patient to open their jaw against resistance