The facial nerve exits the skull through which foramen?

Explanation

## Exit Point of the Facial Nerve (CN VII) **Key Point:** The facial nerve exits the skull through the **stylomastoid foramen**, located between the styloid process and mastoid process on the temporal bone. ### Anatomical Landmarks ```mermaid flowchart TD A[Facial Nerve CN VII]:::outcome --> B[Travels through petrous temporal bone]:::action B --> C[Exits at stylomastoid foramen]:::action C --> D[Emerges between styloid & mastoid processes]:::outcome D --> E[Enters parotid gland]:::action E --> F[Divides into 5 terminal branches]:::outcome ``` ### Foramina of the Skull Base – Comparative Reference | Foramen | Nerve(s) / Structure | Location | | --- | --- | --- | | **Stylomastoid** | **CN VII (Facial)** | **Between styloid & mastoid processes** | | Foramen ovale | CN V3 (mandibular division) | Greater wing of sphenoid | | Foramen spinosum | Middle meningeal artery, CN V3 meningeal branch | Greater wing of sphenoid | | Jugular foramen | CN IX, X, XI; internal jugular vein | Between temporal & occipital bones | **High-Yield:** The stylomastoid foramen is the ONLY skull base foramen through which CN VII exits. This is a frequently tested anatomical fact. **Mnemonic:** **FOAMS** — Foramen Ovale (V3), Foramen spinosum (MMA), stylomastoid (Facial) — helps distinguish CN VII's exit point from other foramina. **Clinical Pearl:** In Bell's palsy or parotid surgery, the facial nerve is at risk immediately after exiting the stylomastoid foramen as it enters the parotid gland. Iatrogenic injury here results in ipsilateral facial paralysis.