Facial Nerve

Question 1

The facial nerve arises from which branchial arch?

Answer 1

2nd branchial arch

Question 2

The facial nerve contains two branches…

Answer 2

branchial motor
sensory and parasympathetic

Question 3

The facial nerve emerges from the brainstem and travels through

Answer 3

Internal acoustic Meatus
Petrous part of Temporal Bone
Genu and Facial Canal
Foramen Stylomastoid

Question 4

The branches of the facial nerve are

Answer 4

Great petrosal nerve
Nerve to Stapeid Muscle
Nerve to chorda timpani
Sensory branch (unnamed)
Nerve to Stylohoid
Posterior Auricular Nerve
Nerve to the posterior belly of digastric muscle
Temporal Branches
Zygomatic Branches
Buccal Branches
Mandibular/Marginal Branches
Cervical Branches

Question 5

What are the modalities of the facial nerve?

Answer 5

Brachial motor
Visceral motor
General Sensory
Special Sensory

Question 6

Brachial Motor

Answer 6

Stapedius, Stylohoid, Posterior Belly of Digastric and Muscles of Facial Expression

Question 7

Visceral Motor

Answer 7

Lacrimal gland, Submandibular and Sublingual glands, Mucosal glands of the nose and palate

Question 8

General Sensory

Answer 8

Skin of Concha of auricle, small area of skin behind ear, wall of external acoustic meatus and external tympanic membrane

Question 9

Special Sensory

Answer 9

Taste from anterior 2/3 of tongue and hard and soft palates

Question 10

Brachial motor pathway

Answer 10

UMN from the cerebral cortex
Sinapsis in the pons facial motor nucleus with a LMN
LMN emerges from the pons and moves toward the Internal Acoustic Meatus
Enter the petrous part of the temporal bone into the facial canal
First within the facial canal branches out the Nerve to the Stapedius, later the facial nerve emerges from the stylomastoid foramen and branches into the posterior auricular nerve
Nerve to the stylohyoid
Nerve to posterior belly of digastric
Temporal Branches
Zygomatic Branches
Buccal Branches
Mandibular/Marginal Branches
Cervical Branches

Question 11

Motor neurons from the cortex send axons to both motor nuclei of CN VII (bilateral input). Neurons in the dorsal half of these nuclei receive input from…

Answer 11

Both sides of the cortex (bilateral input)

Question 12

Motor neurons from the cortex send axons to both motor nuclei of CN VII (bilateral input). Neurons in the ventral half of these nuclei receive input from…

Answer 12

The opposite side of the cortex (contralateral input)

Question 13

Muscles in the upper half of the face are innervated by neurons that receive…

Answer 13

Bilateral Input

Question 14

Muscles in the lower half of the face are innervated by neurons that receive…

Answer 14

Contralateral input

Question 15

Upper motor neuron lesions are associated with

Answer 15

Damage due to strokes

Question 16

Lower motor neuron lesions are associated with…

Answer 16

Bells Palsy Syndrome

Question 17

Visceral Motor (Parasympathetic) Pathway

Answer 17

Parasympathetic fibers from the Hypothalamus move to the Superior Salivatory Nucleus in the Pons
From here the branches emerge: Nervus Intermedius, Greater petrosal nerve, and Chorda tympani

The greater petrosal nerve travels through the pterygopalatine canal to the pterygopalatine ganglion here it makes synapsis, and postsynaptic fibers will use branches from the zygomatic and trigeminal nerve (ophthalmic branch) to innervate the lacrimal gland

Postsynaptic Fibers from the Pterygopalatine Ganglion will emerge as the posterior nasal (inferior and lateral) nerves and the nasal palatine nerve to innervate the mucosal nasal glands

Chorda tympani will emerge from the facial nerve and exit through the petrotympanic fissure using the route of the lingual nerve (one of the branches of the mandibular branch of the trigeminal nerve) will gain access to the submandibular ganglion (synapses) and then some fibers will continue to the submandibular gland and others to the sublingual gland

Question 18

General Sensory Pathway

Answer 18

Dendrites bring information through the nerves intermedium, from

skin posterior to the ear,
the skin of the concha of the auricle,
wall of the external acoustic meatus, external tympanic membrane

The cell body of afferent fibers found in the Geniculate Ganglion

Axons will synapse with neurons in the spinal nucleus of CN V within the brainstem.

Second order neurons go to the thalamus synapse with third order neurons that go to the sensory cortex

Question 19

Special Sensory Pathway

Answer 19

Dendrites bring taste information through the chorda tympani and the greater pretosal nerve from:

anterior 2/3 of tongue
soft and hard palate

Cell body of afferent fibers found in the geniculate ganglion

Axons will enter the brainstem through the nerves intermedius and synapse with neurons in the nucleus solitaries of the brainstem