Facial Nerve Nucleus Branches

Facial Nerve Nucleus

Facial Nerve Origin & course:

1.Facial Nerve  Originates in pons:

• The facial nerve is attached to the lateral surface of brainstem close to caudal border of the pons by two roots, sensory & motor

2. Enters internal acoustic meatus:

• At the bottom of the meatus, the two roots fuse to form a single trunk, which lies in petrous temporal bone

3. In the facial canal:

• The course is divided into three parts

1. 1. First part- Directed above the vestibule
   2. (Second part-present above the promontory
   3. Third part- Lies behind the promontory

• • • First bend is sharp called genu
    • Second bend is gradual

4. Extracranial course:

• Exits skull via stylomastoid foramen
• Courses through parotid gland
• Divides into terminal branches which emerges along the anterior border of the parotid gland

Dangerous area of the face:

• The facial vein communicates with the cavernous sinus through its deep connections
• The facial vein is devoid of valves & rests directly on the facial muscles
• The movements of facial muscles facilitates the spread of emboli from the infected area of upper lip & lower part of the nose in retrograde direction & causes thrombosis of cavernous sinus
• Hence the upper lip & the adjoining nose lying between the angular & deep facial veins forms dangerous area of face