Which of the following structures is NOT innervated by the facial nerve (CN VII)?

Explanation

## Innervation of Head and Neck Muscles by CN VII **Key Point:** The facial nerve (CN VII) innervates muscles of facial expression, stapedius, posterior belly of digastric, stylohyoid, and platysma. The mylohyoid and anterior belly of digastric are innervated by the trigeminal nerve (CN V₃), not CN VII. ### CN VII Motor Branches and Their Targets | Structure | Innervation | Nerve | | --- | --- | --- | | Muscles of facial expression | Orbicularis oculi, buccinator, etc. | CN VII | | Stapedius | Dampens stapes vibration | CN VII (via nerve to stapedius) | | Posterior belly of digastric | Elevation of hyoid bone | CN VII | | Stylohyoid | Elevation and retraction of hyoid | CN VII | | Platysma | Skin of neck and lower face | CN VII | | Mylohyoid | Depression of mandible, elevation of hyoid | CN V₃ (trigeminal) | | Anterior belly of digastric | Depression of mandible | CN V₃ (trigeminal) | | Tensor veli palatini | Soft palate elevation | CN V₃ (trigeminal) | **High-Yield:** Remember that CN V₃ (mandibular division of trigeminal) innervates the muscles of mastication AND the mylohyoid and anterior belly of digastric. This is a common source of confusion in anatomy exams. **Mnemonic:** **SSPP** for CN VII muscles — **S**tapedius, **S**tylohyoid, **P**latysma, **P**osterior belly of digastric (plus muscles of facial expression).