1. Facial Nerve (motor)
1.1. Nerve
1.1.1. Emerges from the brain stem between the pons and medulla.
1.1.2. Exits the skull (cranium) via the stylomastoid foramen.
1.2. Sensory
1.2.1. Receives taste sensation from anterior 2/3rds of tongue.
1.3. Motor
1.3.1. Gives branches immediately after emerging from the skull
1.3.1.1. Nerve to the posterior belly of digastric
1.3.1.2. Posterior auricular nerve (to occipitalis)
1.3.1.3. Nerve to stylohyoid
1.3.2. Terminal branches to muscles of facial expressions (within the parotid gland)
1.3.2.1. Temporal nerve
1.3.2.1.1. Frontal belly of occipito-frontalis, corrugator supercilii, muscles of the auricle, orbicularis oculi
1.3.2.2. Zygomatic nerve
1.3.2.2.1. Orbicularis oculi
1.3.2.3. Buccal nerve
1.3.2.3.1. Muscles of upper lip, buccinator & orbicularis oris
1.3.2.4. Marginal mandibular nerve
1.3.2.4.1. Muscles of lower lip and chin
1.3.2.5. Cervical nerve
1.3.2.5.1. Platysma
1.4. Parasympathetic
1.4.1. Submandibular salivary glands.
1.4.2. Sublingual salivary glands.
1.4.3. Lacrimal glands
1.5. Clinical Relevance
1.5.1. Bell's palsy
1.5.1.1. Paralysis or severe weakness of the muscles of facial expression.
1.5.1.2. Causes
1.5.1.2.1. Infections - Inflammation of facial nerve near stylomastoid foramen.
1.5.1.2.2. Fracture of temporal bone.
1.5.1.2.3. Tumors of face.
1.5.1.3. Symptoms
1.5.1.3.1. Loss of symmetry on the face.
1.5.1.3.2. Wrinkles disappear from forehead (Frontalis and corrugator supercilii).
1.5.1.3.3. Inferior eyelid evert from surface of eyeball (Orbicularis oculi).
1.5.1.3.4. Any attempt to smile draws the mouth to normal side.
1.5.1.3.5. Cannot whistle or blow a wind instrument (Buccinator).
1.5.1.3.6. Food accumulates between the teeth and the cheek (Buccinator).
1.5.1.3.7. Weakened lip muscles affect speech.
2. Trigeminal Nerve (sensory)
2.1. Ophthalmic division (V1)
2.1.1. Distribution
2.1.1.1. Upper third of the face (upper eyelid, conjunctiva of the eye, skin of the forehead, scalp and dorsum of the nose).
2.1.2. Branches
2.1.2.1. Supraorbital nerve
2.1.2.2. Supratrochlear nerve
2.1.2.3. Lacrimal nerve
2.1.2.4. Infratrochlear nerve
2.1.2.5. External nasal nerve
2.2. Maxillary division (V2)
2.2.1. Distribution
2.2.1.1. Middle third of the face (nose, skin of the zygomatic region, cheeks and Upper lip).
2.2.2. Branches
2.2.2.1. Infraorbital nerve
2.2.2.2. Zygomaticofacial nerve
2.2.2.3. Zygomaticotemporal nerve
2.3. Mandibular division (V3)
2.3.1. Distribution
2.3.1.1. Lower third of the face (skin around ears, chin and lower lip).
2.3.2. Branches
2.3.2.1. Auriculotemporal nerve
2.3.2.2. Mental nerve
2.3.2.3. Buccal nerve