Nerve
Facial nerve (CN VII)
Facial expression, taste, tears, saliva
High-yield
Bell's palsy (LMN) affects the whole half-face; a central (UMN) lesion spares the forehead. Runs through the internal acoustic meatus and stylomastoid foramen.
Overview
The seventh cranial nerve, supplying the muscles of facial expression and carrying taste from the anterior tongue plus parasympathetic fibres to the lacrimal and salivary glands.
Reference facts
- Roots
Motor, sensory, and parasympathetic (cranial nerve)
- Course
Passes through the internal acoustic meatus, the facial canal (giving branches), and exits the stylomastoid foramen to branch across the face (parotid plexus)
- Motor
Muscles of facial expression, stapedius, stylohyoid, and posterior belly of digastric
- Sensory
Taste from the anterior two-thirds of the tongue (via chorda tympani); parasympathetic to lacrimal, submandibular, and sublingual glands
Clinical correlation
Bell's palsy causes unilateral facial droop with inability to close the eye or raise the eyebrow on that side.