https://stream.echo6.co/videos/watch/a3676321-acd2-4a49-9b94-27b69257e2e8 Official Ninja Nerd Website: https://ninjanerd.org Ninja Nerds! Join us in this lecture where Professor Zach Murphy will be discussing the oculomotor nerve, cranial nerve III, detailing its anatomy, functions, and clinical correlations. We begin by outlining its origin in the midbrain at the level of the superior colliculus, emerging from the oculomotor nucleus and the Edinger-Westphal nucleus. From there, we follow its course through the interpeduncular fossa, passing between the posterior cerebral and superior cerebellar arteries, and traveling within the lateral wall of the cavernous sinus before entering the orbit through the superior orbital fissure. We then break down the motor and parasympathetic components of CN III. The somatic motor fibers innervate four of the six extraocular muscles—superior rectus, medial rectus, inferior rectus, and inferior oblique, and the levator palpebrae superioris, elevating the upper eyelid. The parasympathetic fibers, originating from the Edinger-Westphal nucleus, synapse in the ciliary ganglion and innervate the sphincter pupillae (pupil constriction) and ciliary muscles (lens accommodation). This dual function is critical for coordinated eye movement, pupillary reflexes, and focusing. We also discuss key clinical correlations, including the effects of CN III palsy such as ptosis, a “down and out” eye position, diplopia, and a dilated, nonreactive pupil when parasympathetic fibers are involved. Special attention is given to the vulnerability of these superficial parasympathetic fibers to compressive lesions (such as a posterior communicating artery aneurysm) and the deep motor fibers to ischemic injury (such as in diabetes mellitus). Enjoy the lecture and support us below! 🌐 Official Links Website: https://www.ninjanerd.org Podcast: https://podcast.ninjanerd.org Store: https://merch.ninjanerd.org 📱 Social Media https://www.tiktok.com/@ninjanerdlectures https://www.instagram.com/ninjanerdlectures https://www.facebook.com/ninjanerdlectures https://x.com/ninjanerdsci/ https://www.linkedin.com/company/ninja-nerd/ 💬 Join Our Community Discord: https://discord.gg/3srTG4dngW #ninjanerd #OculomotorNerve #CranialNerves Wed, 15 Apr 2026 09:26:49 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://stream.echo6.co https://stream.echo6.co/client/assets/images/icons/icon-512x512.png https://stream.echo6.co/videos/watch/a3676321-acd2-4a49-9b94-27b69257e2e8 All rights reserved, unless otherwise specified in the terms specified at https://stream.echo6.co/about and potential licenses granted by each content's rightholder.