facial nerve

By Ebtisam AL-thawab ~

The facial nerve is classified as a Multi-functional .

Its branches act as

1. ( Motor Function )

2. (Parasympathetic function )

3. ( Sensory Function)

A.Temporal

B.Zygomatic

C.Buccal

D.Mandibular

E.Cervical

Branch Supplying

• Temporalis Auricular and fronto-occipitalis muscles . The temporal

branch acts as the efferent limb of the corneal reflex.

• Zygomatic Supplies the muscles of the zygomatic arch and orbit.

• Buccal Supplies muscles in the cheek and above the mouth.

• Mandibular Supplies the muscles in the region of the mandible but

not the muscles of mastication.

• Cervical Supplies the platysma muscle of the neck.

The facial nerve innervates all the branchiomeric muscles , in

addition to the posterior belly of the

digastric, stylohyoid muscle, and the strapedius muscle of the

middle ear .

• The sense of taste is referred to as a gustatory sense and the tongue is the main taste organ.

• This anterior portion of the tongue is defined as the area in front of the terminal sulcus and primarily has taste buds that detect sweet, sour and salty flavours.

• The sense of taste is referred to as a gustatory sense and the tongue is the main taste organ.

• Sensations of taste from the anterior two-thirds of the tongue travel through the peripheral axons of nerve cells located in the geniculate ganglion on the facial nerve, before passing via the thalamus to the taste area on the cortex.

Parasympathetic Function

The facial nerve gives off two separate parasympathetic nerves.The first is the Greater petrosal nerve and the second is

the Chorda tympani.

The Greater Petrosal Nerve travels through the middle ear and eventually combines with the deep petrosal nerve to form the nerve of the pterygoid canal .

Chorda tympani• Supplies fibers to

the submandibular gland and sublingual glands. It serves to increase the flow of saliva from these glands. It also supplies parasympathetic innervation to the nasal mucosa and the lacrimal gland via the pterygopalatine ganglion.

• The facial nerve also functions as the efferent limb of the Corneal reflex , an involuntary blinking of the eyelids elicited by stimulation of the cornea (such

as by touching or by a foreign body)

Fiber Nerve Function

Branchial motor

(special visceral

efferent)

Supplies the muscles of facial

expression; posterior belly of digastric muscle; stylohyoid, and stapedius.

Visceral motor

(general visceral

efferent)

Parasympathetic innervation of the

lacrimal, submandibular, and sublingual

glands, as well as mucous membranes of nasopharynx, hard and soft palate.

Special sensory

(special afferent)

Taste sensation from the anterior 2/3 of tongue; hard and soft palates.

General sensory

(general somatic

afferent)

General sensation from the skin of the

concha of the auricle and from a small area behind the ear

• Textbook of Medical Physiology, Guyton and Hall , W

B Saunders Co 2011 .

• Principles of Neural Science By Eric R.Kandel

• Garde, M.M., & Cowey, A. (2000). "Deaf hearing":

Unacknowledged detection of auditory stimuli in a

patient with cerebral deafness. Cortex 36(1), 71-80