Retina | An Introduction | Part 1 Like this video? Sign up now on our website at https://www.DrNajeebLectures.com/ to access 800+ Exclusive videos on Basic Medical Sciences & Clinical Medicine. These are premium videos (NOT FROM YOUTUBE). All these videos come with English subtitles & download options. Sign up now! Get Lifetime Access for a one-time payment of $99 ONLY! Sign up now on our website at https://members.drnajeeblectures.com/ --------------------------------------------------------------------------------------------------------------------------- Why sign up for premium membership? Here's why! Membership Features for premium website members. 1. More than 800+ Medical Lectures. 2. Basic Medical Sciences & Clinical Medicine. 3. Mobile-friendly interface with android and iOS apps. 4. English subtitles and new videos every week. 5. Download option for offline video playback. 6. Fanatic customer support and that's 24/7. 7. Fast video playback option to learn faster. 8. Trusted by over 2M+ students in 190 countries. --------------------------------------------------------------------------------------------------------------------------- ▬▬▬▬▬▬▬▬▬▬ Contents of this video ▬▬▬▬▬▬▬▬▬▬ (0:00-3:40) Delicate membranous light-sensitive part of the eye, location in the eye ball; Outermost protective layer= Sclera & Cornea. Middle layer (Uveal Tract) = Choroid, Ciliary body & Iris. Innermost layer= Retina; pigmented epithelium, Innermost Neuronal layer of Retina. (3:41-9:30) Exact location of Retina; sandwiched between Vitreous Body inside (Vitreous aspect of retina) and Choroid outside (Choroidal part of retina). Ora Serrata; Wavy margins where light sensitive part of retina terminates anteriorly. (9:35-13:20) Through the Ophthalmoscope: Only posterior part of retina i.e., Optic Disc and part around it visible; Ocular Fundus. Non-light sensitive part of retina; continuing beyond Ora Serrata. (13:22-23:20) Embryological Development of Eye: CNS development; Neural Tube; Optic Vesicle to Optic Cup; Outer and Inner layers differentiate into outer pigmented & inner neuronal retinal layers. Retina, therefore is the only part of CNS visible through ophthalmoscope. (23:25-29:10) Fundoscopy: Posterior pole of fundus(yellowish) [Macula Lutea]; Optic Disc nasally/medially (pale colored). Macula Lutea in detail: Has undefined margins, slight depressed area in center; Fovea Centralis. (29:15-34:25) Optic Disc in detail: Highly vascular (Central Retinal Artery coming out of it), Optic Disc; point of Retina from where all optic nerve fibers are moving out of retina through lamina cribrosa as Optic Nerve. Technically Optic Nerve is a CNS tract and not a nerve per say. (34:30-38:40) Optic Disc continued: Central Retinal Artery, branches after passing through the Optic Disc & its Nasal & Temporal branches then supply inner parts of Retina. Outer part of Retina supplied by Choriocapillaris. (38:41-41:30) Optic Disc continued; Central Retinal Artery (CRA) continued: Fovea Centralis (FC); the area of maximal visual acuity, depends only on Choriocapillaris for nutrition & not CRA, therefore NO Blood Vessels: Avascular. Further comparison of Macula Lutea and Optic Disc. (41:31-43:44) Clinical Co-relate of Optic Disc (OD): Physiological Cup: Depression in OD; In Glaucoma when ICP is very high, this cup is pushed backwards; pathologically cupped/depressed. No rods & cones here so; Blind Spot. Comparison continued: In Fovea Centralis (FC), cones are packed very tightly & blood vessels basically pushed aside to reveal FC; hence thinnest area of the retina; sharpest acuity. (43:48-45:30) Summary of comparison b/w OD & Macula Lutea (ML); 1- OD nasally situated, ML central but inferolateral to OD. 2-OD = 1.5mm, while ML = 5-6mm. 3-OD is pale, ML yellowish. 4- OD = Blood vessels coming in & out; highly vascular, while ML = Avascular. 5- OD is a blind spot while ML has point of maximal visual acuity. 6-OD has 'Physiological cupping' while ML has Fovea Centralis. 7-OD has sharper margins, while ML much diffused, undefined margins. (45:31-51:00) Blood supply of Fovea Centralis. Descriptive schematic diagram of OD, ML, Optic Nerves and Retinal Arteries, along with their positions in eyeball from above. --------------------------------------------------------------------------------------------------------------------------- Join this channel to get access to the perks: Sign up now on our website at https://members.drnajeeblectures.com/ Follow us on Facebook:- https://www.facebook.com/DrNajeeb/ Follow us on Instagram:- https://www.instagram.com/drnajeeblectures/