The Teeth: Tooth Tales of Ripping, Grinding, and Tearing
| Objective: | to observe the different
ways teeth begin digesting foods
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| Student Information: | Chewing
is the first step in the digestion of food. Baby teeth are called
deciduous which means to fall off at maturity. Deciduous
teeth cannot grow to fit the adult jaw, so they fall out and are replaced
by secondary teeth.
Teeth are not bones. They are much stronger than bones. Each tooth is made up of four layers: the pulp (containing the nerves and blood vessels), the dentin (the hard inside), the enamel (the tough outer coating) and the cementum (the outer coating of the tooth's roots, which cements the tooth to the gums). Types of human teeth: canine
(sharp and pointy shapes used for cutting and tearing), incisors
(big, flat wedge shapes used for biting food off), bicuspids (two-pointed
shapes used for grinding) and molars (flat, squared shapes used
for grinding).
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| Materials: | (for each student)
samples of foods such as apples, celery, leafy lettuce, nuts, raisins, cereal, pudding, cheese cubes, fruit leathers, peanut butter, prepared gelatin squares |
| Procedures: | 1. Have students eat
samples of the different types of foods.
2. Ask - Did some foods
require more chewing than others? Why? Which foods required tearing or
grinding? Did any foods require no chewing at all? Why not?
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| Assessment: | Graphing
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Digest This
| Objective: | to describe how the teeth
and stomach work together to begin the digestive process
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| Student Information: | Your stomach is like a stretchy
bag that holds your food after you eat. Your stomach also helps to break
your food into smaller pieces so your body can use it.
About ten seconds after you swallow your food, it reaches your stomach. Your food reaches your stomach through a tube called your esophagus. Little glands in your stomach make special juices that are waiting for your food. Once your food enters your stomach, your muscles move the walls of your stomach. Your stomach mashes your food the way a baker kneads dough for bread! Your food gets mashed and stirred with the special juices. The juices and the mashing help to break your food into smaller pieces. This process is called digestion. Your stomach has a door in that closes to keep food inside. It keeps food inside to work on for a few hours. Your stomach can stretch out to hold almost two quarts of food! When it has digested your food as much as it can, the door opens and your food travels into your small intestine. When your stomach is empty,
it shrinks like a balloon without air. Your stomach is a stretchy storage
tank!
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| Materials: |
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| Procedures: | 1. Divide the class
into pairs, and give each pair two jars.
2. Put some potato chunks in one jar. Put some grated potato in the other jar. Add water to each jar. Fasten each lid. 3. Students take turns shaking both jars for 10 minutes. 4. Look at the mixture.
Discuss what happened to the potato.
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| Assessment: | Journal Entry
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| Source: | Addison-Wesley |
Your Small Intestine
| Objective: | to identify the function
of the small intestine
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| Student Information: | Food moves from your stomach
into your small intestine. Inside this 20-foot-long tube, juices
break the food down into tinier bits. Your small intestine squeezes
food along like you squeeze toothpaste through a tube. Tiny hairlike villi
cover the inside walls of your small intestine. Villi are like doors
in the walls of your intestine. Food goes through the villi and
out into your bloodstream.
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| Materials: |
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| Procedures: | Work in pairs. Food has
to be tiny to go through the villi. Mix the pepper and water in
a cup. Pour it through a paper towel into another cup. What went through
the paper towel and what did not?
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| Assessment: | Journal Entry
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Your Large Intestine
| Objective: | to identify the function
of the large intestine and review the digestive process
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| Student Information: | Your body can't use everything
you eat. The things your body doesn't use are wastes. As food is
squeezed through your small intestine, useful bits are taken into
your bloodstream. Your large intestine gets the rest of the
watery mixture.
Your large intestine
takes out water and other liquids your body can use. Then it squeezes the
leftover solid bits of waste called feces out through an opening
called the anus. These are the wastes you flush down the toilet.
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| Materials: |
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| Procedures: | 1. Discuss the function
of the large intestine. Use the chart to show the location of the
large intestine in relation to the other organs of digestion.
2. The students will work
in pairs. Using the chart as a reference, students will draw, label and
paste in the correct order the parts of the digestive system ( including
the teeth, esophagus, stomach, small intestine, and large intestine.
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| Assessment: | Journal Entry
1. What are wastes? What does the large intestine squeeze out of the wastes? Where does the large intestine push the wastes? 2. Using the chart, tell what happens during the digestive process. Begin with the teeth.) |
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