Задание для самостоятельного изучения – составить лексический словарь к следующим текстам (выписать незнакомые слова с переводом)
THE EYE
CONCEPTS: 1. Our sense of sight is the response of the brain to light stimuli which are received by the eye. 2. The eye is a delicate organ with highly specialized tissue.
BACKGROUND INFORMATION: The delicate eye is well protected and cared for. It is enclosed by bone on all but one side; eyelids, eyelashes, and tears keep the eyeball clean, moist, and germ free. The eyeball is covered by a tough white tissue called the sclera. It is commonly referred to as the “white of the eye”. The sclera reflects light except in a small area in the front of the eye called the cornea. The cornea, made of transparent tissue, allows light to pass through it. Behind the cornea is the iris – the colored part of the eye. Light does not pass through the iris, but tiny muscles within the iris can change the size of the iris and affect the size of the pupil, the dark opening in the center of the iris. The pupil is dark because the inside of the eyeball is dark. The pupil lets light pass into the eyeball, depending on the amount of light that strikes the eye. Bright light makes the pupil smaller; dim light makes the pupil larger. Light passes through the pupil to the lens which brings the rays of light together and in focus upon the retina. The retina is the sensitive lining of cells (rods and cones) on the back of the eyeball. The focus point of light upon the retina is called the fovea. Light images strike the retina as an upside – down image; the sensitive nerves of the retina send this inverted impulse to the brain through the optic nerve. The brain interprets the inverted impulse as a rightside – up image. It is in the brain that we experience the sensation of sight. For this reason many people say we “see” with our brain. Eyeglasses are used to bend light and focus light rays in such a manner as to improve our most precious sense, sight
THE EAR
CONCEPTS: 1. Our sense of hearing is the response of the brain to sound stimuli which are received by the ear. 2. The human ear is divided into three parts – outer, middle, and inner ear.
BACKGROUND INFORMATION: The outer ear collects and funnels sound waves, which are air vibrations, through the auditory canal to the eardrum. The eardrum is a thin membrane (tissue) stretched across the end of the auditory canal. When sound waves strike the eardrum, it begins to vibrate. The vibrations from the eardrum cause the three tiny bones of the middle ear (hammer, anvil, and stirrup) to vibrate, too. The vibration continues to the inner ear. Within the inner ear is the cochlea – a delicate organ shaped like a snail’s shell filled with fluid and tiny nerve endings. When vibrations reach the cochlea, it sends nerve impulses to the auditory nerve leading to the brain. The brain interprets the various impulses as sound. Semicircular canals are also found in the inner ear. These are three tubes shaped like semi – circles filled with fluid and nerve endings. Different body and head movements cause the fluid within the semicircular canals to move and change position which in turn affects our sense of balance. The eustachian tube connects the middle ear with the throat. The purpose of this tube is to permit equalization of air pressure in the middle ear. This is necessary so that the pressure on both sides of the eardrum will be the same. Improved designs of hearing aids, advances in ear (otic) surgery, and new medicines are helping many persons enjoy the fascinating world of sound.
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