Cranial Nerves (CN I–XII)
For NEET PG, focus on the functional components, nuclei location, and exit points from the skull. Mnemonics are essential for rapid recall during the exam.
1. Quick Reference: Name & Function
| CN | Function | Skull Exit |
|---|---|---|
| I | Olfactory (Sensory) | Cribriform plate |
| II | Optic (Sensory) | Optic canal |
| III, IV, VI | Eye Movement | Superior orbital fissure |
| V | Trigeminal (Mixed) | V1, V2, V3 (S, R, O) |
| VII | Facial (Mixed) | Internal acoustic meatus |
| VIII | Vestibulocochlear | Internal acoustic meatus |
| IX, X, XI | Mixed | Jugular foramen |
| XII | Hypoglossal (Motor) | Hypoglossal canal |
2. NEET PG “Must-Know” Pearls
- Parasympathetic Nuclei: Remember the four ganglia: Ciliary (III), Pterygopalatine (VII), Submandibular (VII), and Otic (IX).
- Trigeminal V3: The only division of CN V that carries motor fibers (muscles of mastication).
- Tongue Innervation: Taste = VII (anterior 2/3), IX (posterior 1/3); Sensation = V3 (anterior 2/3), IX (posterior 1/3); Motor = XII (all except palatoglossus).
- The “4-4-4” Rule: Midbrain has I-IV; Pons has V-VIII; Medulla has IX-XII.
Board Hint: Examiners love to ask about the cavernous sinus. Know that III, IV, V1, V2, and VI pass through it. CN VI is the most centrally located and often the first to be compressed in mass lesions within the sinus.