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25 Cards in this Set
- Front
- Back
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What is the electromagnetic spectrum?
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A range of waves of different wavelengths. Includes gamma rays, x-rays, ultraviolet, visible light, infra-red and microwaves.
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Identify the limited range of wavelengths detected by humans
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380 - 750nm
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What is refraction?
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The bending of light as it passes between two mediums of differing density
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Where does refraction occur in the eye?
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In the cornea, aqueous and vitreous humour and the lens.
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What is accommodation?
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When the shape of the lens is changed to focus.
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What is Myopia?
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Myopia is short-sightedness. The image is focused in front of the lens. Close objects can be seen clearly while distant objects are blurred.
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What is Hyperopia?
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Hyperopia is long sightedness. The image is focused behind the retina. Distant objects can be seen clearly while close objects are blurry.
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What technologies are available to correct Myopia and Hyperopia?
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Glasses and contact lenses can be used. Refractive surgery can be done, where a laser is used to reshape the cornea so that the light is refracted at the correct angle.
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What is colour blindness and what is the cause of this condition?
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colour blindness is when one or more of the colour detecting cones are damged or missing. It is a sex linked disease carried on the x chromosome and more common in boys that girls.
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Why is sound a useful and versatile form of communication?
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- sound travels well in air and water
- the sender doesn't have to be visable to the reciever -it is useful in the dark -can go around objects -can travel over long distances -a wide variety of sounds can be produced |
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What is a stimulus?
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a change in the environment detected by a receptor
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What are receptors?
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Part of the nervous system that detect a stimulus
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What are effectors?
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Muscles or glands that are capable of producing responses to stimuli
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What is the conjunctiva and what is its function?
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A mucous membrane that covers the eye. It protects the eye and keeps it moist.
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identify the structure and function of the Cornea
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It is the transparent front part of the eye that refracts light entering the eyeball.
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What is the structure and function on the Sclera?
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It is the tough white outer coating of the eye. Protects the eye.
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What is the iris?
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It is the pigmented tissue that contains two sets of muscles to control the size of the pupil and the amount of light entering the eye
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What does the lens do?
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The lens is a transparent protien disk that focuses light onto the retina.
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What is the ciliary body?
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It contains the ciliary muscles and suspensory ligaments that hold the lens in position. It connects the choriod with the lens. Alters the shape of the lens.
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What is the choroid?
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A dark pigmented layer inside the sclera containing many blood vessels. Absorbs and prevents light from scattering.
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What is the structure and function of the Retina?
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It is the inner layer of the eye, contains photoreceptor cells FOVEA and BLIND SPOT. changes light into nerve impulses.
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What is the optic nerve?
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the nerve which connects the eye to the brain. It carries information from the eye to the brain.
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List the parts of the ear involved in hearing
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Pinna, Tympanic Membrane, Ear ossicles, Oval window, Round Window, Cochlea, Organ of Corti, Auditory nerve.
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Name two types of photoreceptor cells found in the human eye
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Rods and Cones
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What are ossicles?
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small bones in the middle ear.
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