Anatomy and physiology of the eye pdf

Aqueous and Vitreous Humor Aqueous Humor is the clear liquid in the anterior chamber front of the eye. Retina Thin semitransparent multi-layered sheet of neural tissue that lines the inner layer of the posterior section of the globe of the eye. Photoreceptor Cells: Rods Require little light to work effectively and at night gives a primarily grayish image Generally do not give clear vision Relatively Sensitive to Light Responsible for peripheral vision Bundled in groups of 30, 40 or to nerves that transmit image to the brain.

Carrots and your Vision Carotene, an element of vitamins A and B, triggers the chemical reaction of the rods. Madhu Malesh. Taslima Oyebode. Muhammad Irfan. Amritashu Bardhan. Jilda Kaya. Gurpreet Channa. Giulio Francesca. Thibault Toussaint. Bello-Osagie Aghatise Teslim. Ambrish gYpr. Lusia Nasrani. Praveen Ganesan. Salman Jindran. Siddharth Shekhar. Radio One v. Mark Jaffe. Popular in Belief. Bcex Pesantren.

Ale Garte. Debbie de Guzman. Puteri Shakira. Angel Dida Liwa. Some of the most common retinal diseases include diabetic retinopathy DR , and age-related macular degeneration AMD. AMD exits in two forms: dry atrophic and wet exudative or neovascular. AMD is always bilateral, but not always the same form in both eyes.

Also, the disease does not necessarily progress at the same rate in both eyes. Both AMD and DR involve degeneration of retinal structure which leads to disruption of the phototransduction pathway discussed. In diabetic retinopathy, blood vessels and neurons are damaged by an overaccumulation of glucose, and in severe disease, the proliferation of new blood vessels can further exacerbate visual impairments.

In AMD, there is a buildup of damaged cellular components such as lipofuscin intracellular and drusen extracellular. This leads to damage to the macula which causes dysfunctional central vision and can ultimately lead to complete blindness. Choroidal neovascularization can also exacerbate AMD. Many different genes have been implicated in the development and progression of AMD. In contrast to achromatopsia, retinitis pigmentosa RP affects the rod cells of the retina.

Rods are progressively lost as the disease advances, leading to difficulty seeing at night, and decreased peripheral vision which has been described as "tunnel vision". Symptoms often begin in childhood and progressively worsen with age. Mutations in many genes have been shown to cause RP, with possible inheritance patterns including autosomal dominant, autosomal recessive, X-linked, and mitochondrial inheritance.

Schematic diagram of the human eye. Contributed by the Public Domain. This book is distributed under the terms of the Creative Commons Attribution 4. Turn recording back on. National Center for Biotechnology Information , U. StatPearls [Internet].

Search term. Physiology, Eye Parker E. Author Information Authors Parker E. Affiliations 1 Creighton University School of Medicine. Introduction The proper function of the eye depends on its ability to receive and process energy from light in the environment, produce action potentials in specialized nerve cells, and relay those potentials through the optic nerve cranial nerve II to the brain. Issues of Concern Visual acuity relies on proper refraction or bending of light passing through structures of varying densities as the light is transmitted through the cornea, aqueous humor, lens, and vitreous humor before striking the retina.

Cellular The retina is comprised of two types of photoreceptor cells: rods and cones. Mechanism The photopigment in rods is called rhodopsin. Clinical Significance Astigmatism refers to a blurring of vision due to the irregular curvature of the cornea or the lens.

Review Questions Access free multiple choice questions on this topic. Comment on this article. Figure Schematic diagram of the human eye. References 1. Kawamura S, Tachibanaki S. Rod and cone photoreceptors: molecular basis of the difference in their physiology.

Rapid and reproducible deactivation of rhodopsin requires multiple phosphorylation sites. Suppressing autophagy protects photoreceptor cells from light-induced injury. Biochem Biophys Res Commun. Evolution of the vertebrate phototransduction cascade activation steps. The book is comprised 10 chapters that cover the functions and properties of the parts of the ocular system. The text first provides a review of ocular. Clinical Anatomy and Physiology of the Visual System. Clinical Anatomy of the Eye by Richard S.

Snell,Michael A. Ocular and Visual Physiology by Simon E. The Eye by John V. Sensory Systems by Aage R. Anatomy of the Eye and Orbit by Thomas F. Freddo,Edward Chaum. Models of the Visual System by George K. Hung,Kenneth C. Download Now Download Download to read offline. Anatomy and physiology of the eyelid Oct. Alaa Farsakh Follow. Ophthalmology Resident at Al-Islami Hospital.

Anatomy of lacrimal apparatus. Anti vegf intravitreal injections. What to Upload to SlideShare. A few thoughts on work life-balance. Related Books Free with a 30 day trial from Scribd. Related Audiobooks Free with a 30 day trial from Scribd. Anatomy and physiology of the eyelid 1. Amjad Younis 2. A semilunar fold called plica semilunaris lies on lateral side of caruncle. The punctum leads to canaliculus lacrimalis. Structure of the eyelids 13 1. Skin: 2. Subcutaneous tissue 3.

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