U3F1ZWV6ZTYzMDQ3MjM2NjJfQWN0aXZhdGlvbjcxNDIzODIzNjY5
recent
Latest

Facial nerve anatomy, course and branches

(A) Intracranial part

Facial nerve has 3 nuclei:
  1. Motor nucleus lies in pons.
  2. Superior salivatory nucleus: in pons, parasympathetic secretomotor to lacrimal, submandibular, and sublingual glands.
  3. Nucles solitarius: in medulla, sensory, carries taste sensation from the tongue.
Motor fibers form the motor root, while parasympathetic and sensory fibers join to form the sensory root (nervus intermedius).

The 2 roots emerge on the side of the brain stem, at junction between pons & medulla to cross CPA to I.A.M. Controlled by pyramidal & extrapyramidal fibers.

(B) Cranial (intratemporal) part: 

    37-45mm.

  1. Labyrinthine segment: runs in the I.A.C superior to VIII & anterior to superior vestibular nerve, runs laterally to medial wall at geniculate ganglion.
  2. Tympanic (horizontal) segment: starts at geniculate ganglion, curves to form 1st genu, runs backwards in medial wall till the posterior wall.
  3. Mastoid (vertical) segment: Runs inferiority (2nd genu), lies antero inferior to lat. SCC, then vertically downwards to leave skull at stylomastoid foramen.

(C) Extra cranial part:

Enters parotid gland >> divides into terminal motor branches.

Branches of Facial nerve

(1) In temporal bone.

a) Greater superficial petrosal: arises at geniculate ganglion >> secreto motor parasympathetic to lacrimal, nasal, palatine glands.

b) Nerve to stapedius: motor supply to stapedius.

c) Chorda tympani: exit just above stylomastoid foramen to enter ME >> carries taste from ant. 2/3 of tongue & secretomotor parasympathetic to sub lingual and sub mandibular glands.

(2) After exit from skull:

Two motor branches to stylohyoid & post belly of digastric.
Posterior auricular nerve: motor to occipital belly of occipitofrontalis.

(3) Five terminal branches in parotid:

Temporal, zygomatic, buccal, mandibular & cervical supply muscles of scalp, face, auricles & platysma.
Edit Post
author-img

Tamer Mobarak

Comments
    No comments
    Post a Comment

    Post a Comment

    Please note that we will be notified by e-mail about your comment , So be careful .
    Any medical questions will be answered .

    NameEmailMessage