All cranial nerves and foramina where they pass from
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Searching for comprehensive cranial nerve anatomy and foramina information.
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cranial nerves foramina skull base passage exit
Bailey and Love's Short Practice of Surgery 28th Edition
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cranial nerves foramina skull base diagram
Hugging Face pmc clinical VQA raw
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Here is a complete reference table of all 12 cranial nerves and the foramina/openings through which they exit the skull:
All 12 Cranial Nerves and Their Foramina
| # | Nerve | Foramen / Opening | Skull Fossa |
|---|---|---|---|
| CN I | Olfactory | Cribriform plate (foramina of the ethmoid bone) | Anterior cranial fossa |
| CN II | Optic | Optic canal | Middle cranial fossa |
| CN III | Oculomotor | Superior orbital fissure | Middle cranial fossa |
| CN IV | Trochlear | Superior orbital fissure | Middle cranial fossa |
| CN V₁ | Trigeminal — Ophthalmic | Superior orbital fissure | Middle cranial fossa |
| CN V₂ | Trigeminal — Maxillary | Foramen rotundum → infraorbital foramen (exits face) | Middle cranial fossa |
| CN V₃ | Trigeminal — Mandibular | Foramen ovale → mental foramen (exits face) | Middle cranial fossa |
| CN VI | Abducens | Superior orbital fissure | Middle cranial fossa |
| CN VII | Facial | Internal acoustic meatus → exits skull via stylomastoid foramen | Posterior cranial fossa (enters); temporal bone (exits) |
| CN VIII | Vestibulocochlear | Internal acoustic meatus | Posterior cranial fossa |
| CN IX | Glossopharyngeal | Jugular foramen | Posterior cranial fossa |
| CN X | Vagus | Jugular foramen | Posterior cranial fossa |
| CN XI | Accessory (Spinal) | Spinal rootlets enter skull via foramen magnum, then exits via jugular foramen | Posterior cranial fossa |
| CN XII | Hypoglossal | Hypoglossal canal (anterior condylar canal) | Posterior cranial fossa |
Grouped by Foramen
| Foramen | Cranial Nerves Passing Through | Also Contains |
|---|---|---|
| Cribriform plate | CN I | Anterior ethmoidal artery |
| Optic canal | CN II | Ophthalmic artery |
| Superior orbital fissure | CN III, IV, V₁, VI | Superior ophthalmic vein |
| Foramen rotundum | CN V₂ | — |
| Foramen ovale | CN V₃ | Accessory meningeal artery |
| Foramen spinosum | — | Middle meningeal artery (no cranial nerve) |
| Internal acoustic meatus | CN VII, VIII | Labyrinthine artery |
| Stylomastoid foramen | CN VII (exit) | — |
| Jugular foramen | CN IX, X, XI | Internal jugular vein, sigmoid sinus |
| Foramen magnum | CN XI (entry), brainstem–spinal cord junction | Vertebral arteries, anterior/posterior spinal arteries |
| Hypoglossal canal | CN XII | — |
Key Memory Points
- "Standing Room Only" (Superior Orbital Fissure): CN III, IV, V₁, VI all pass through it — damage causes a complete ophthalmoplegia + forehead anesthesia
- CN V has 3 branches exiting through 3 separate foramina (cribriform → no; superior orbital fissure, foramen rotundum, foramen ovale)
- CN VII travels the longest intracranial bony canal — enters at the internal acoustic meatus and exits at the stylomastoid foramen through the facial canal in the temporal bone
- Jugular foramen is the busiest posterior fossa opening: CN IX, X, and XI plus the internal jugular vein
- CN VIII never leaves the skull to supply a peripheral structure directly — it terminates in the cochlea and vestibular apparatus
- CN XI is unique: its spinal roots ascend through the foramen magnum before exiting via the jugular foramen
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