Cranial Nerves + The Eye PDF
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Uploaded by EnterprisingNonagon
Monash University Malaysia
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Summary
This document is an educational resource about the trochlear nerve, a cranial nerve that controls the superior oblique muscle of the eye. It describes the nerve's function, course, and potential causes of palsy. It is focused on medical anatomy and physiology.
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CN IV: Trochlear Nerve Function: General somatic motor only → Superior oblique muscle Course: Smallest cranial nerve but longest intracranial course The fibres from each trochlear nucleus cross within the midbrain Emerges from the posterior aspect of the midbrain (the only CN to exit posteriorly)...
CN IV: Trochlear Nerve Function: General somatic motor only → Superior oblique muscle Course: Smallest cranial nerve but longest intracranial course The fibres from each trochlear nucleus cross within the midbrain Emerges from the posterior aspect of the midbrain (the only CN to exit posteriorly) Runs anteriorly in the subarachnoid space then pierces to dura mater to enter the cavernous sinus Exits the cranial cavity to reach the orbit via the superior orbital fissure CN IV Palsy: Damage to CN IV can be caused by: ○ Microvascular damage: Diabetes or hypertension ○ Congenital malformation ○ Raised ICP ○ Thrombophlebitis of the cavernous sinus Loss of function of the superior oblique ○ Head tilt away from the affected side → to compensate for unopposed extortion ○ Vertical diplopia exacerbated by looking down and in (reading or walking down stairs)
