Question
The nerve supplying the superior oblique muscle exits the brainstem at which of the following sites:
A. A
B. B
C. C
D. D
Show Answer
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Correct Answer » B Explanation |
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Ans: B. B
(Ref: Gray’s 41e 1)664, 670, 40/e. p276)
- Superior oblique muscle is supplied by the fourth cranial nerve (Trochlear nerve).
- Only nerve that exits the brainstem from its posterior aspect.
| Structures Marked in the | |
| A | Oculomotor nerve |
| B | Trochlear nerve |
| C | Abducens nerve |
| D | Facial nerve |
| Cranial Nerves Location | |
| Cribriform plate (CN I) | Olfactory nerve |
| Middle cranial fossa (CN II-VI)
sphenoid bone |
Optic canal (optic nerve, ophthalmic artery, central retinal vein)
Superior orbital fissure [oculomotor, trochlear, Ophthalmic (V1) nerve abducens, ophthalmic vein, sympathetic fibers] Foramen rotundum [Maxillary (V2) nerve Foramen rotundum [Maxillary (V2) nerve Foramen spinosum (middle meningeal artery) |
| Posterior cranial fossa (CN VII-XII)
through temporal or occipital bone |
Internal auditory meatus (Facial & Vestibulocochlear nerve)v
Jugular foramen (Glossopharyngeal, vagus, spinal accessory nerve, internal jugular vein)` Hypoglossal canal (Hypoglossal nerve)Q Foramen magnum (Spinal roots of spinal accessory nerve, brainstem & vertebral arteries. |