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Visual Communication involves the eye registering changes in the immediate environment. COMMUNICATION: HSC BIOLOGY OPTION. The outer eye:. CONJUNCTIVA. A thin, transparent mucous membrane that covers the sclera (the white of the eye). It lines the inner surfaces of the eyelids.
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Visual Communication involves the eye registering changes in the immediate environment COMMUNICATION:HSC BIOLOGY OPTION
CONJUNCTIVA • A thin, transparent mucous membrane that covers the sclera (the white of the eye). • It lines the inner surfaces of the eyelids. • Tiny secretory glands in the produce tear film that lubricates and protects the eye while it moves in its socket and helps to keep it clean. • It covers and protects the surface of the cornea
CORNEA Transparent front window through which light enters the eyeball.
SCLERA • The external layer of the eye continuous with the cornea. • The white of the eye.
SCLERA • Tough, non elastic tissue protects the delicate inner layers of the eye. • It helps to maintain the shape of the eyeball. • Attachment for the external muscles of the eye which enable the eyeball to move in the socket.
LENS - Biconcave disc Refracts light rays & focuses them on the retina.
CILIARY BODY- Holds the lens in place yet allows flexible movements of the lens.Secretes the aqueous humour
IRIS • Coloured part of the eye • A ring of muscle with a hole in the middle (the pupil). • Controls size of pupil & amount of light entering eye. • In dim light pupil dilates to let more light in. • In bright light the iris tightens and the pupil contracts.
RETINA • The inner layer of the eye. • Contains photoreceptors for vision • Highly specialised rod & cone cells respond to light, converting light energy into nerve impulses.
Aqueous & Vitreous Humour • Transparent watery fluid • Provides nutrients for the lens & cornea. • Clear jelly-like substance • Refracts light • Helps maintain the shape of the eyeball
CHOROID • The middle layer of the eye which extends into the iris • A sheet of blood vessels that carries oxygen & nutrients to the eye and remove carbon dioxide and wastes • Posteriorly it is black which prevents light in the eye from scattering.
OPTIC NERVE Transfers the visual signals to the brain for processing.
Bibliography: • http://www.wolfeeyeclinic.com/images/cornea.jpg • http://www.geocities.com/centennial3d/labelledexterior2.jpg • http://homepage.ntlworld.com/pshinde/index_nt_files/picture_data/sclera_dot_.jpg • http://www.stlukeseye.com/popups/images/Choroid.jpghttp://jbooy.files.wordpress.com/2008/10/j01retina.jpg • http://static.howstuffworks.com/gif/adam/images/en/retina-picture-c.jpg • http://fc02.deviantart.com/fs27/f/2008/042/0/0/Iris_Eye_Macro_Stock_by_zpyder.jpg • http://www.msstrength.com/wp-content/themes/zen/images/optic_nerve.jpg