Facial nerve

Question 1

Fibres of facial nerve

Answer 1

• General somatic afferent (GSA)
• Special visceral afferent (SVA)
• General visceral efferent (GVE)
• Special visceral efferent (SVE, brachiomotor)

Question 2

Origin of facial nerve

Answer 2

Cerebellopontine angle(motor and sensory roots)

Question 3

Facial nerve exits skull through

Answer 3

Stylomastoid foramen

Question 4

Facial nerve nuclei

Answer 4

• Motor nucleus of facial nerve (SVE)
• Superior salivatory nucleus (GVE)
• Nucleus of solitary tract (SVA)
• Principal sensory nucleus of trigeminal nerve (GSA)

Question 5

Associated ganglia of facial nerve

Answer 5

Geniculate ganglion(pterygopalatine ganglion, otic ganglion, submandibular ganglion)

Question 6

What are the main parts of the facial nerve

Answer 6

• Intracranial
• Intratemporal
• Extracranial

Question 7

Parts and branches of the intracranial part of the facial nerve

Answer 7

Origin-> Internal accoustic meatus(no branches)

Question 8

Parts and branches of the Intratemportal part of the facial nerve

Answer 8

• Internal accoustic meatus-> Stylomastoid foramen
• Greater petrosal nerve
• Nerve to stapedius muscle
• Chorda tympani

Question 9

Parts and branches of the Extracranial part of the facial nerve

Answer 9

• After stylomastoid foramen
• Posterior auricular nerve
• Digastric branch
• Stylohyoid branch
• Parotid plexus(Temporal, Zygomatic, Buccal, Marginal, cervical)

Question 10

Main functions of facial nerve

Answer 10

• Motor innervation to muscles of facial expression (SVE)
• Taste to anterior two thirds of tongue and palate (SVE)
• Parasympathetic innervation of lacrimal, nasal, palatine and salivary glands(except parotid)(GVE)
• Sensation to part of auricle and retroauricular region

Question 11

Sensations of facial nerve

Answer 11

• Motor and sensory

Question 12

Intracranial course of Facial nerve

Origin of motor root of facial nerve

Answer 12

• Motor nucleus of facial nerve at lower pontine tegmentum

Question 13

Intracranial course of Facial nerve

Merge with fibres of the **superior salivatory nucleus **and then pass to floor of fourth ventricle

Answer 13

Motor root axons

Question 14

Intracranial course of Facial nerve

• The motor root axons loop around the nucleus of this nerve before exiting brainstem at the cerebellopontine angle

Answer 14

Abducens nerve

Question 15

Intracranial course of Facial nerve

Fibres of the sensory root travel towards this structure to reach the nucleus of solitary tract

Answer 15

Medulla

Question 16

Intracranial course of Facial nerve

Nucleus of solitary tract

Answer 16

Visceral sensory part of brainstem involved with relaying signals of satiety

Further fibers projected to principal sensory nucleus of trigeminal nerve

Question 17

Intratemporal course of Facial nerve

Facial nerve roots course as they leave cranial cavity

Answer 17

Via **internal acoustic meatus **to enter facial canal in petrous part of temporal bone

Here they fuse to form facial nerve proper

Question 18

Intratemporal course of Facial nerve

Facial nerve roots make sharp anterior to posterior turn at this point

Answer 18

Geniculum of facial nerve

Question 19

Intratemporal course of Facial nerve

Facial nerve roots enlarge at this point

Answer 19

Geniculate ganglion

Question 20

Intratemporal course of Facial nerve

Contains the cell bodies of the sensory neurons of the facial nerve

Answer 20

Geniculate ganglion

Question 21

Intratemporal course of Facial nerve

Arises directly from the geniculate ganglion

Answer 21

Greater petrosal nerve

Question 22

Intratemporal course of Facial nerve

Arise before the facial nerve exits the temporal bone

Answer 22

• Nerve to stapedius muscle
• Chorda tympani

Question 23

Extracranial course of Facial nerve

Facial nerve leaves facial canal through this foramen

Answer 23

Stylomastoid foramen

Question 24

Extracranial course of Facial nerve

After exiting through stylomastoid foramen, the facial nerve gives off this nerve before entering the parotid gland

Answer 24

Posterior auricular nerve

Question 25

# Extracranial course of Facial nerve After giving off the posterior auricular nerve, the facial nerve enters this gland where it has 5 terminal branches

Answer 25

Parotid gland

Question 26

# Intratemporal branches On its course to foramen lacerum, merges with deep petrosal nerve carrying sympathetic fibers to form

Answer 26

Nerve of the pterygoid canal

Question 27

# Intratemporal branches Greater petrosal nerve innervation

Answer 27

* Travels to **pterygopalatine ganglion** to provide parasympathetic innervation to: *** Lacrimal gland** * **Mucous glands of nasal cavity, Maxillary sinus and palate**

Question 28

# Intratemporal branches Second intratemporal branch of facial nerve

Answer 28

Nerve to stapedius muscle

Question 29

Nerve to stapedius muscle innervation

Answer 29

* SVE/branchiomotor fibres * Dampening vibrations and protecting hearing apparatus during exposure to loud sounds

Question 30

# Intratemporal branches Final Intratemporal branch

Answer 30

Chorda tympani

Question 31

# Intratemporal branches Traverses middle ear and exits via petrotympanic fissure

Answer 31

Chorda tympani

Question 32

# Intratemporal branches The chorda tympani merges with this nerve

Answer 32

Posterior aspect of lingual nerve

Question 33

# Intratemporal branches Chorda tympani innervation

Answer 33

* Anterior two thirds of tongue * Submandibular and sublingual glands ## Footnote Salivary secretions

Question 34

# Extracranial branches First Extracranial branch

Answer 34

Posterior auricular nerve

Question 35

# Extracranial branches Posterior auricular nerve innervation

Answer 35

* Motor-> occipitofrontalis muscle * Intrinsic auricular muscles * Skin around external acoustic meatus and retroauricular region

Question 36

# Extracranial branches Digastric and stylohyoid innervation

Answer 36

Motor to there respective muscles

Question 37

# Extracranial branches Facial nerve pierces parotid gland and bifurcates into

Answer 37

Superior and inferior trunks which give rise to five terminal branches

Question 38

# Extracranial branches Terminal branches of facial nerve

Answer 38

To Zanzibar By Motor Car * Temporal * Zygomatic * Buccal * Marginal mandibular * Cervical

Question 39

# To Zanzibar By Motor Car Temporal branch innervation

Answer 39

* Frontalis * Orbicularis occuli * Currugator supercilii muscles

Question 40

# To Zanzibar By Motor Car Zygomatic branches innervation

Answer 40

* Orbicularis oculi muscle

Question 41

# To Zanzibar By Motor Car Buccal branches innervation

Answer 41

* Orbicularis oris * Buccinator * Zygomaticus muscles

Question 42

# To Zanzibar By Motor Car Marginal mandibular branches innervation

Answer 42

* Depressor labii inferioris * Depressor anguli oris * Mentalis

Question 43

# To Zanzibar By Motor Car Cervical branches innervation

Answer 43

Platysma muscle

Question 44

Areas of the facial nerve, lesions can occur

Answer 44

* Intracanial * Intratemporal * Extracranial

Question 45

# Intratemporal facial nerve lesions Damage to the nerve near its origin, the geniculate ganglion or within facial canal leads to these symptoms

Answer 45

* Loss of motor function * Taste and autonomic functions affected

Question 46

# Intratemporal facial nerve lesions Lesions affecting greater petrosal nerve result in

Answer 46

* Impaired lacrimal fluid production ipsilaterally

Question 47

# Intratemporal facial nerve lesions Lesions affecting nerve to stapedius muscle result in

Answer 47

Hypersensitivity to sound

Question 48

# Intratemporal facial nerve lesions Lesions affecting chorda tympani

Answer 48

* Reduced salivary secretion of submandibular and sublingual glands * Loss of gustatory function of anterior two thirds of tongue ipsilaterally

Question 49

# Extracranial facial nerve lesions After leaving skull, facial nerve damage along extracranial course affects

Answer 49

Motor fibres

Question 49

# Extracranial facial nerve lesions Lesions affecting extracranial facial nerve fibres cause

Answer 49

Facial nerve palsy-paralysis or weakness in muscles of facial expression

Question 50

# Extracranial facial nerve lesions Extracranial lesions aetiology

Answer 50

* Idopathic-bells palsy * Infection-viral(Herpes) * Iatrogenic-surgery(removal of parotid) * Compression(forceps baby delivery)

Question 51

Sudden ipsilateral facial paralysis with no detectable cause

Answer 51

Bells palsy