Anatomy-Trigeminal Nerve

Question 1

Name the three divisions of the trigeminal nerve?

Answer 1

Opthalmic

Maxillary

Mandibular

Question 2

Where does the opthalmic divison of the trigeminal exit the Skull?

Answer 2

Supra-orbital notch

Question 3

Where does the maxillary division of the trigeminal nerve exit the skull?

Answer 3

Infra-orbital foramen

Question 4

Where does the mandibular divison of the trigeminal nerve leave the skull?

Answer 4

Mental foramen

Question 5

Label A, B,C

Answer 5

A- supra-orbital notch

B- infra-orbital foramen

C- Mental foramen

Question 6

Label these parts of the palate:

Answer 6

A- palatine process of the maxilla

B- Horizontal plate of the palatine bone

C- Incisive Foramen

D- greater palatine foramen

E- Lesser palatine foramen

Question 7

Label the parts of the mandible

Answer 7

A- condylar process

B- Ramus

C- angle

E- mental foramen

F- Body

G- Head

H- Neck

J- coronoid process

K- mandibular foramen

L- lingula

Question 8

What passes through the mandibular foramen?

Answer 8

Inferior alveolar nerve.

Question 9

Where are teeth found in the jaw?

Answer 9

The alveolar process

Question 10

Where does the trigeminal nerve originate from ?

Answer 10

Special visceral efferent nuclei

General somatic Afferent nuclei

Question 11

Compare the motor and sensory nuclei of the trigeminal nerve.

Answer 11

There is 1 divison called the motor nucleus

There are 3 sensory divisons:
Mesencephalic nucleus

Chief sensory nucleus

Spinal nucleus.

Question 12

Label this diagram:

Answer 12

A- motor

B- mesenchephalic

C- chief sensory

D- spinal nucleus.

Question 13

WHat is the function & location of:

Motor nucleus?

Answer 13

LOCATION: pons

Function: muscles of mastication.

Question 14

Compare the function and location of the Sensory nuclei?

Answer 14

Mesencephalic - midbrain - Proprioception

Chief sensory - Pons - discriminative touch

Spinal- medulla Oblongata - temperature and pain?

Question 15

What is the terminal ganglion?

Answer 15

This is what the Sensory and motor nuceli exit the pons to become. This is before the trigeminal nerve divides into 3 divisons.

Question 16

Where is the terminal ganglion found?

Answer 16

In meckle’s cave.

Question 17

Explain the connection between the nuclei, the terminal ganglion and the Trigeminal nerve divisions.

Answer 17

the nuclei join together to become the terminal ganglion which then splits to become the divisions of the trigeminal nerve.

Question 18

Where does CNV₁ pass when it seperates from the trigeminal nerve?

Answer 18

Towards the superior orbital fissure.

Question 19

Where does CNV₂ pass when it seperates from the trigeminal nerve?

Answer 19

Through the foramen rotundum.

Question 20

Where does CNV₃ pass when it seperates from the trigeminal nerve?

Answer 20

Through the foramen ovale.

Question 21

Label this image

Answer 21

A- trigeminal ganglion

B- CNV3 foramen ovale

C-CNV2 foramen rotundum

D- CNV1

Question 22

Name the branches of the opthalmic division

Answer 22

A- nasociliary

B- lacrimal

C-Frontal

D- supraorbital

E- supratrochlear

F-anterior ethmoidal

G- infratrochlear

H- long ciliary

I- external nasal

Question 23

Two of the branches of the opthalmic nerve are connected.

Which ones and discuss the connection?

Answer 23

The anterior ethmoidal continues to the tip of the nose as the external nasal nerve.

Question 24

What is shingles ?

Answer 24

reactivation of the dormant chicken pox virus.

Question 25

Name & Discuss this foramen?

Answer 25

Foramen rotundum- This is where the maxillary divison of CNV exits. This can only be identified on the inner aspect of the skull.

Question 26

Where does the maxillary division divide?

Answer 26

Inferior orbital fissure.

Question 27

Name the branches of the zygomatic divison of the trigeminal nerve?

Answer 27

Zygomaticotemporal Zygomaticalfacial.

Question 28

What is the function of the infra-orbital branches?

Answer 28

These supply the lower eyelid / cheeks/ upper lip & nose

Question 29

Describe the pathway of the nasopalatine nerve?

Answer 29

1. Nasopalatine nerve 2. Sphenopalatine foramen 3. Passes incisive canal to the hard palate.

Question 30

Compare the 3 branches of the Superior alveolar nerve.

Answer 30

Anterior superior Alveolar nerve-comes from the infra orbital branch Middle superior alveolar nerve - comes from the infra orbital branch. Posterior superior alveolar nerve (its own seperate branch)

Question 31

What does the alveolar nerve do?

Answer 31

It provides a nerve supply to the teeth and gums.

Question 32

Label the alveolar nerves.

Answer 32

A- anterior superior alveolar nerve B- Middle superior alveolar nerve C- posterior superior alevolar nerve

Question 33

Discuss the palatine branches?

Answer 33

The palatine branch goes down the palatine canal before spliting into the greater and lesser palatine nerve. These supply the palate.

Question 34

Label these nerve branches in the palate:

Answer 34

A- lesser palatine nerve B- greater palatine nerve C- Nasopalatine nerve

Question 35

What is the relevance of the maxillary branch of trigeminal nerve to local anaesthetic?

Answer 35

The maxillary branch of the trigeminal nerve supplies the teeth and the gums.

Question 36

Label the branches of the Maxillary of the trigeminal

Answer 36

A-Infra-orbital B- zygomaticofacial C- Zygomaticotemporal D-Zygomatic E- Anterior superior alveolar F- middle superior alveolar G- posterior superior alveolar H- greater palatine nerve I- lesser palatine nerve J- posterior superior alveolar K- palatine nerves L- infra-orbital nerve M-zygomatic nerve N- nasal nerve

Question 37

What are the boundaries of the Infra-temporal fossa?

Answer 37

Anterior- Posterior aspect of Maxilla lateral - Ramus of mandible inferior- angle of mandible Superior- Infratemporal crest of sphenoid bone Posterior - Styloid process, mastoid process & tympanic plate Medial- Lateral Pterygoid plate of the sphenoid bone.

Question 38

What are the branches of the mandibular division of the trigeminal nerve?

Answer 38

* Inferior alveolar * Auriculotemporal * Buccal * Lingual * Mental * Muscular

Question 39

Label the branches of the mandibular main trunk

Answer 39

A- meningeal branch B- posterior branch C- Anterior branch D-Medial pterygoid E- tensor tempani F- Tensor Veli palatini

Question 40

Label this diagram of the anterior trunk of the trigeminal nerve

Answer 40

A- Masseteric B- Deep temporal nerves C-Lateral pterygoid D- Buccal nerve

Question 41

Label this diagram of the posterior trunk of the mandibular

Answer 41

A- lingual B- auriculotemporal C- inferior alveolar

Question 42

Compare the divisions that come from the main branch of the mandibular?

Answer 42

Meningeal- sensory Medial pterygoid -motor Tensor Tempani -motor Tensor Veli Palatini-motor

Question 43

Compare the divisions that come from the anterior trunk.

Answer 43

Deep temporal branches- motor Buccal - sensory Masseteric- motor Lateral pterygoid- motor

Question 44

Compare the divisions that come from the posterior trunk

Answer 44

Lingual- Sensory auriculotemporal- Sensory Inferior alveolar- mixed

Question 45

How is the inferior alveolar "mixed"

Answer 45

Superior to the mandible the inferior alveolar is mixed sensory and motor. The nerves then split into a sensory part (becomes mental branch and incisive branch) and a motor branch to the mylohyoid

Question 46

Discuss the lower oral cavity sensory supply:

Answer 46

Cheeks and gums- buccal Posterior lower teeth- main branch of inferior alveolar Anterior lower teeth- incisive branch of inferior alveolar. Lower lip and skin of the chin- mental

Question 47

Why can a LA cause the tip of the tongue to go numb?

Answer 47

The lingual nerve is located very near the Inferior alveolar nerve. So the lingual nerve can also be blocked.

Question 48

Discuss the sensory innervation of the anterior 2/3 of tongue.

Answer 48

General sensory- temperature and pain - lingual nerve of Mandibular divison of trigeminal. Special sensory- taste - Chordae tympani of the facial nerve.

Question 49

What anatomical relations are there to an inferior alveolar block & what happens if they are touched?

Answer 49

* Blood vessels- parotid plexus * Medial pterygoid - hitting this can cause trismus- muscle spasm- patient cannot open mouth. * Parotid gland- if you inject deep enough you hit facial nerve * Facial nerve- if hit causes palsy & loss of taste. This should wear off within a day- but need to appologise to patient.