GRADE: Fourth

CONTENT STANDARD: Life Science

CONTENT TOPIC: Anatomy

CONCEPT: The human body is composed of sensory organs which detect heat, light, and sound.

CONTENT OBJECTIVE: 4G2.00 To understand the proper care of sensory organs

INSTRUCTIONAL OBJECTIVE: The learner will:

2.01 choose appropriate procedures for proper care of the ear.
2.02 choose appropriate procedures for proper care of the eye.
2.03 choose appropriate procedures for proper care of the skin.
2.04 choose appropriate procedures for proper care of the nose.
2.05 choose appropriate procedures for proper care of the tongue.

I. Ear Care
II. Eye Care
III. Skin Care
IV. Nose Care
V. Tongue Care

TN COMPONENT OF SCIENCE: Science In Society

TN GOAL:

To enable students to demonstrate attitudes toward science in solving problems and making personal decisions about issues affecting the individual, society, and the environment.

4.2 PERSONAL NEEDS - The application of science may be used to change the quality of life for the individual

4.2a Any individual can participate in and contribute to the process of science.

BENCHMARK: People use and contribute to science to improve their lives.

4.2b Science concepts may be applied to personal decisions.

BENCHMARK: Individual behavior may be influenced by an understanding of science concepts

TIME REQUIRED:

Five class periods

charts or models of eye, ear, or skin; pencil; paper; filmstrips on sensory organs

SET:

(Talk-but make no sound-see how long it takes the class to catch on.) Would you like to live in a world that was absolutely silent? Raise your hand if you know some ways you can care for your ears. (response) The ears are considered to be the second most important sense organs. For this reason caring for the ears is most important. Today we will learn several ways to care for your ears.

"Never put anything into your ear smaller than your elbow." Perhaps you have heard this statement before. What do you think this statement means? (response - Call on someone to answer.) Them statement means a person should avoid using sharp or pointed objects to remove ear wax. Such objects can easily puncture the eardrum or scratch the external auditory canal. What effect might such injuries have on a person's hearing? (response)

Another way people can avoid injuring their ears is by protecting their ears from loud noises. What is noise? (response) You may recall that when sound waves strike the eardrum, they cause the eardrum to vibrate. When sound waves from something making a soft sound strike the eardrum, the eardrum vibrates with slight force. But when sound waves from something making a loud sound strike the eardrum, the eardrum vibrates with great force. The loud sound waves can cause the eardrum to vibrate with so great a force that the eardrum tears. How might that effect a person's hearing? (response) Explain your answers. (response)

Besides the eardrum, certain other parts of the ear can be affected by noise. Those parts are the nerve cells sensitive to sound vibrations. Each cell of your body carries out its activities most efficiently when you are at rest. The nerve cells within your ears, like all the other cells of your body, also tire. But the nerve cells within the ears tire quickly when sound waves are very loud or continue for an extended period of time. When either situation occurs, the tired nerve cells within the ears tend to send fewer impulses than normal to the brain, causing a temporary loss of a certain amount of hearing.

Have you ever noticed that when you have a cold, you sometimes cannot hear as well as you normally do? The reason a cold sometimes affects a person's hearing is that it often affects the air pressure in the middle ear.

Air always presses against the body, including the outer side of the eardrum. But vibrate normally, the air pressure against the inner side of the eardrum must be the same as that against the outer side. Keeping the air pressure against the inner side of the eardrum equal to the pressure against the outside of the eardrum is the function of a small tube, the Eustachian tube.

The Eustachian tube extends from the throat to the middle ear. Normally, air moves in and out of that tube, keeping the pressure against the inner and outer side of the eardrum equal. But when you have a cold, mucus and swelling caused by the irritation of the germs tend to close off the Eustachian tube. That keeps air from moving in or out of the middle ear, causing the air pressure against the inner side of the eardrum to be different from the air pressure against the outer side of the eardrum. Moreover, when you blow your nose, some of the mucus and the germs can easily be forced up through the Eustachian tube to the middle ear. If those germs reach the middle ear, they cause a middle ear infection. How might you help avoid such an infection? (response)

Still another way people can help care for their ears is by having their ears examined regularly. A doctor who specializes in problem of the ear is called an Otologist. Might people benefit from having their hearing tested regularly, even though the results of those tests may show that their level of hearing is normal? (response) Why or why not? (response)

(Let students make a list of jobs people work at that the loud noises could cause damage to the ear. Share their lists with the class.)

Today we have learned several ways you might care for your ears. Write two ways you can protect your ears against injury. Share with your neighbor. (pause) (Call on individuals to share with the class, summarize.)

Have children research hearing tools such as hearing aids and ear tubes.

This Classroom Connector addresses Instructional Objective 2.02.

SET:

Think about the things you do during a typical week. For example, do you read a book or a newspaper? Do you cross a busy street? Do you call a friend? Do you buy things? Do you watch TV or go to a movie? People often do one or more of those things during a typical week. Yet most people seldom think about how much they depend upon their eyes to help them do such things. The eyes are considered to be the most important sense organs because people receive most of the information about the environment through their eyes. Today, we will learn about ways of taking care of our eyes.

One of the ways you can help care for your eyes is to protect them against injury. There are many things in the environment that can injure your eyes. For example, do you have household cleaners in your home? Or cans that spray such things as paint or deodorant? (response) Any of these substances can injure your eyes if they get into the eyes. What might you do to protect your eyes against injury due to things such as those just mentioned? (response) How might you protect your eyes against injury from other things in our environment? (response)

Another way you can help care for your eyes is to have your eyes examined regularly by a doctor who is specially trained to care for the eyes. An Ophthalmologist is a physician, or doctor, who specializes in the diagnosis and the treatment of eye problems through the use of medicines, surgery, or corrective lenses. Another doctor specially trained to care for the eyes is called an optometrist. An optometrist is a doctor who treats certain eye problems through the use of eye exercises and corrective lenses. Why would having your eyes examined regularly by a doctor be a way you can help care for them? (response)

Air pollution affects many organs of the body. Two of those organs are the eyes. Some of the pollutants in air that affect the eyes are gases. One of those gases is carbon monoxide.

Carbon monoxide is found mainly in the exhaust fumes of automobiles and in tobacco smoke. When breathed in, carbon monoxide is picked up by the blood more easily than oxygen. As a result, when a person breathes air containing carbon monoxide, less oxygen than normal can be picked up by the blood and carried to each cell of the person's body. When the cells of a person's body receive less oxygen than normal, the cells cannot carry out their activities as efficiently as they should. Since the eyes are made up of cells, those cells are also affected when they do not receive the normal supply of oxygen. How might that affect a person's vision? (response)

Besides carbon monoxide, there are certain other gases that contribute to air pollution and that affect the eyes. Those gases include sulfur oxides, which come mainly from the burning of fuels such as oil and coal; and hydrocarbons, which come mainly from the burning of gasoline. When these gases come in contact with the eyes, the gases irritate the eyes, causing the eyes to tear excessively and to burn. Do you think constant irritation of the eyes by these gases might be harmful to the eyes? (response)

There are some problems of the eyes that you cannot prevent. These include far-sightedness, near-sightedness, astigmatism, and color blindness.

Your eyes are valuable tools. They deserve the best care you can give them. An important part of such care is being aware of changes in the way your eyes function and doing something about them.

Seek medical treatment if you develop one or more of these symptoms: loss of sight; blurred or hazy vision; seeing halos around lights; seeing flashes of lights even when your eyes are closed; loss of side vision; severe or repeated headaches; frequent squinting or frowning; double vision; loss of normal night vision; reddened, burning, itching, or painful eyes; or crusting of the eyelids.

Ask an optometrist for an eye chart. Students work in pairs to test their eyes. If they wear glasses or contact lenses, test each eye with and without them.

Name three causes of injury to your eyes. Share them with your neighbor. (pause) What are three ways you can care for your eyes? Share them with your neighbor. (pause) (Call on one or two students to share with the class.

Invite an optometrist to your classroom to discuss the latest technology breakthroughs in treatment of eye disease or injury.

This Classroom Connector addresses Instructional Objective 2.03.

SET:

What is the largest organ in the body? (response) What can measure over 19,000 square centimeters (3,000 square inches)? What organ has many functions? The answer to each of these questions is the same. The answer is the skin. We are going to learn about caring for the skin.

Your skin is the covering of your body. Do you ever think about all the things your skin does for you? It protects body tissues from disease-causing organisms, from physical abuse, and from water loss. Your skin helps control body temperature and aids in removing wastes from your body. The skin contains nerve endings that receive sensations of pressure, pain, temperature, and texture. So your skin is something you want to take care of.

The skin has two layers. The inner layer, called the dermis, is made of living cells. The health of this inner layer depends on oxygen and nutrients brought to it by circulating blood. The outer layer of skin is called the epidermis. Dead cells at the top of the epidermis are continually being scaled off and replaced by cells from below.

The health of the epidermis depends largely on cleanliness. A general rule for keeping the skin clean is to wash it at least once a day with soap and water. Yet there are times when this general routine is not enough. Sometimes, special problems arise that require special care. Some of these problems are: dry and oily skin; acne; body odor; fungal infections; sunburn; and skin cancer.

The amount of moisture in your skin has a lot to do with how it looks and feels. When the skin on your hands or other areas is too dry, it may feel tight, sore, rough, and flaky. Dry skin may even crack and bleed. Dry skin can be the result of exposure to wind, cold, or sun. It can be caused by use of soap or detergents, frequent swimming or low humidity.

Emollients, such as bath oil and body lotions are products designed to soften and soothe skin. Emollients may be used to relieve dryness. However, you should choose such products carefully and recognize their limitations. Consult a physician if a dry skin problem seems major. Flaking and bleeding skin can be signs of more serious conditions.

Oily skin may occur for many reasons. A common reason during adolescence is that certain changes in your body cause the oil glands to produce more oil. Such things are heredity, emotions, and temperature also may be factors in producing oily skin.

A product applied to the skin cannot stop the production of oil. However, an excess can be removed from the skin surface. If you have oily areas, it helps to wash them at least twice a day. Oily cosmetics should be avoided.

Acne consists of whiteheads, blackheads, and pimples. It commonly occurs on the face and other oily areas. Severe acne can lead to permanent scarring. However, many who have acne suffer more emotionally than physically. Acne can affect self-confidence and happiness. Unfortunately, there is no cure for acne. Treatment is aimed at preventing scars and reducing the severity of the outbreak.

Perspiration is a natural function that aids in cooling and in removing wastes from the body. However, the same changes in hormones that can cause acne in adolescence also can cause enlargement and over activity of the sweat glands. Perspiration itself is odorless, but the bacteria that are always present on the skin cause the perspiration to develop an unpleasant odor.

Body odor can be controlled, chiefly by keeping ourselves clean. Daily washing with soap and water will get rid of some bacteria on your skin. Because your clothing may pick up some odor from your body, it also is important to wear clean clothes every day.

Fungal infections are caused by fungi. They appear on various areas of the body and can spread from one area of the body to another or from one person to another. Fungi need a moist place in which to live. So it is important to dry your feet well especially between the toes after you wash. Athlete's foot is a fungal infection on the feet. Change your socks or stockings often if you are active physically or if your feet perspire heavily.

Because the sun is an important source of energy for the earth, you probably do not view it as an enemy. Yet overexposure to sunlight damages your skin. Sunlight includes both ultraviolet and infrared radiation. Ultraviolet radiation causes sunburn; infrared radiation does not. Infrared radiation has a warming effect. You feel it as heat. On a cloudy day, less infrared radiation reaches you than on a clear day. Therefore, you may stay outside longer than usual. You may not realize that ultraviolet radiation still is reaching your skin. This can result in sunburn, just as staying out too long on a sunny day would do. Reflection of sunlight from sand, water, or snow increases your exposure to ultraviolet radiation. You may have experienced sunburn. Did you know that sunburn is the same as other burns? (response) In a first degree sunburn, the skin is reddened. In a second-degree sunburn, blisters form. Both sunburns are painful, but a second-degree burn carries the danger of infection.

Even if you avoid sunburn, overexposure to sunlight over the years can cause the skin to prematurely develop a leathery texture, with wrinkles, folds, and sags. This is because the skin loses elasticity as a result of exposure to the sun.

A number of skin problems, such as cold sores, can be aggravated by sunlight. But the most alarming connection between sunlight and disease involves skin cancer. There is evidence that suggests that repeated and persistent exposure to sunlight may be one of the major factors in causing skin cancer in some people. Skin cancer has long been an occupational hazard for farmers, sailors, and ranchers, who are outdoors much of the time. Skin cancer is most common in the United States in the southern and southwestern parts where people are exposed to more sunlight than people in northern areas. Skin cancer usually appears on exposed areas of the body such as the face and hands.

If you need or want to be in the sun, gradual and moderate exposure is the best for both skin care and tanning. Among other things, too much exposure causes the skin to peel, therefore losing some of the tan already acquired. You should use suntan products. The chemicals are known as sun screens. These chemicals absorb some of the sun's ultraviolet radiation.

Display a poster of a very tanned person and one of a person not tanned. The children are to look carefully and then list advantages/disadvantages to each. Share what has been written. (Hopefully, the students will conclude that the "beauty" of tanned skin isn't worth the risk of damaged skin, pain of sunburn, and chance of infection.

We have learned several things each individual can do to take care of his/her skin. Write two and share them with your neighbor. (Allow time to do this.) (Class shares and one or two students can then be called on to state these care steps briefly.)

Have students locate their safe exposure times (according to skin type) from the following suggestion chart:

Minutes of Exposure

Any time thereafter, judge on basis of tenderness or redness

Skin Type Light Medium

1st 15 20

2nd 20 25

3rd 25 30

4th 30 35

This Classroom Connector addresses Instructional Objective 2.04.

SET:

How do you think the sense of smell can help protect you? (response) Can you think of an instance when your sense of smell helped you? (response) Today you will learn why it is important to take care of your nose. The nose has three very important jobs. The jobs are as follows:

1. Warms the air

2. Cleans the air (because of mucus and hairs)

3. Adds moisture to the air (because of mucus)

What is the purpose of breathing? Breathing brings oxygen into your body. Your nose and nasal cavity are a part of a team in your body called the respiratory system. Many tiny hairs inside your nose can trap small specks of dirt. The air you inhale is cleaned in this way. Your moisture inside. This moisture helps trap even smaller pieces of dirt. Sneezing helps keep dust from getting deeper inside your body. The nasal cavity is the air passage behind the nose. It is divided into a right and left passageway. The tissue that covers the wall of nasal cavity has many blood vessels. Heat from the blood in the vessels warms the air as you breathe.

The cells that line your nose and sinuses make a liquid called mucus. Mucus traps dirt and dust. It also keeps your sinuses and the air you inhale moist. Sometimes too much mucus is made. You will have clogged nasal passages when you have a cold. The proper way to blow a clogged nose is to hold the handkerchief tightly, an infection from the nose can travel to the middle ear. Never insert or place an object in the nostrils to get rid of mucus. This can cause a blood vessel to burst. You may get a bloody nose.

The nose can also be examined by a doctor. The doctor will use an instrument called a rhinoscope. The instrument enables the doctor to look at the condition of the lining of the nose. An inflamed, or reddened, lining of the nose may indicate an infection or an allergy, either of which could not only decrease a person's sense of smell but also make breathing difficult.

Do you think coughing and sneezing are ways in which your body protect itself against particles of dirt? Share your answer with your neighbor. Call on someone to share their answer. Do you think it is important to know how to blow your nose properly? Share your answer with your neighbor. (Call on someone to share their answer.)

This Classroom Connector addresses Instructional Objective 2.05.

SET:

What are your favorite foods? (response) What do you like about them, their taste or their smell? (response) It is difficult to distinguish between these two senses. The senses of taste and smell are stimulated when chemicals come in contact with them. Today, we are going to learn about the importance of the tongue and the proper care of the tongue.

The tongue is covered with thousands of tiny projections. Taste buds, the organs for taste, project around these areas. The taste buds are bathed in dissolved food. Chemicals in the food stimulate the taste buds. The taste buds only respond to the tastes of sweetness, sourness, bitterness, or saltiness with each taste being detected on a certain area of the tongue.

The sensory organs are highly specialized. Sensory nerves carry impulses from the senses to the brain. Proper health care is a must to ensure the protection of your sense organs. Be careful with food or drink that is too hot. Food that is too hot will burn the tongue.

The tongue may also be checked by a doctor. The doctor checks the tongue and lining of the mouth for sores or signs of irritation.

Name the four flavors to which your taste buds respond. (pause) Share one thing with your neighbor that you must be careful of to keep from damaging your tongue.

Blindfold students for a taste test!

This is the time this file has been accessed since 07/01/97.

The University of Tennessee at Martin is not responsible for the information or views expressed here.

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