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Muscles.

DID YOU KNOW??

There are 639 muscles in the human body.

Background

How many students would guess that muscles only know how to move one way? After all, we reach high over our heads to throw a ball, twist our arms behind us to scratch, and swing our legs out wide to sit in a comfortable chair. Yet, all of these movements are accomplished in one simple way: a muscle contracts.

Since muscles only contract, how can we accomplish all these different feats? There are complementary muscles working together. One muscle pulls our arm up, but another one is needed to pull our arm back down. Flexor muscles do the pulling up and extensor muscles pull the arm back down. But there's no pushing! Flexors and extensors have to work together, taking turns.

A student can feel these opposite muscles at work. Have him hold out one arm with wrist and fingers straight. Bend the hand up at the wrist. Now stretch it back down. The student should feel muscles on the inside and outside of his lower arm taking turns doing the work. If he moves his hand up and back quickly several times, he will feel that burning sensation that shows us our muscles are working hard on both sides of his lower arm.

We can have fun moving our muscles in different ways. But what about the muscles that are needed to keep our hearts pumping, our stomachs digesting, or our bladders expanding and contracting? And breathing--don't forget breathing. The muscles that control these kinds of activities work all the time without waiting for us to think about it or decide that it's time for them to get busy. These are involuntary muscles. The muscles we worked with before are voluntary muscles--they wait for our brains to volunteer them!

There is one category of muscle that is both voluntary and involuntary. Most of the time, we breathe without having to think about it. We keep breathing in our sleep and even when we are concentrating hard on the math problem in front of us. But we can also choose to take a deep breath or to hold our breath. The muscles that control our breathing work involuntarily, but we can also control them when we wish.

Level Pre-A

Main Concept: Our bodies need muscles to do work.

Initiating Questions--Levels Pre-A--B

1. How many ways can you move your arm?

2. Can you wiggle your nose? Your ears?

3. After you pick something up, can your arm just fall down or do you have to think about bringing your arm down?

Follow-up Questions--Levels Pre-A--B

4. What do we need to move the parts of our bodies?

5. What can we do to keep our muscles strong?

6. Why do some muscles work in pairs?

Picture Activity

What do you see when the girl holds up her arm? Can you see her muscle? WHY FLY is pointing to her arm where her muscles are. Have children make a muscle with their own arms. Have them feel their muscles. Now, they can relax their arms and feel again. How different does a muscle feel when it is relaxed?

Vocabulary

Answers: milk, mustard, mushroom, meat, mirror

Weekly Lab

For Step 3 of this activity, students are asked to lift a chair. Provide a compact, lightweight chair that students will be able to lift off the floor. A folding chair or lightweight wood chair should work well. Ask students, "Did you feel your muscles working? Did you feel the same muscles working for each step?" Generate some discussion so that students learn to be aware of their muscles as they play and exercise. Ask students if they can think of other ways to feel the muscles in their legs, hands, feet.

Math

Answers: 2 children are throwing, 3 children are jumping

Storytelling

Discuss the different muscles WHY FLY is using in each of the pictures. Ask, "Do you think WHY FLY's muscles are only pulling?. Or, are the muscles pushing?." Explain that muscles only do their hard work in one direction--pulling. They never push in the opposite direction. One set of muscles work to pull. Another set of muscles work to pull in the opposite direction. Students can also talk about their favorite exercises. You might want to list them on the board.

Challenge

Ask students if they are surprised to learn that we have muscles that help us eat. What about smiling and swallowing? Where are the muscles to help us do these things?

Bringing it Home

Students can suggest other toys that are good exercise.

DID YOU KNOW??

Your tongue consists of 16 muscles.

Level A

Main Concept: We need muscles to do work. Muscles can only pull. A muscle does not push.

Vocabulary

Students can copy the words from the box in the top right corner if they need help.

Weekly Lab

You may want students to listen for one minute and count the number of heartbeats they hear. You can also have the student count the beats out loud while you watch a second hand for 10 seconds. Multiply the beats by 6 for the number of beats per minute. The number of beats per minute is called the heart rate. Explain that we can know how hard the heart is working by how fast it is beating. The harder it works the faster it beats. You can have students listen for differences before and after doing some exercises.

Math

Answers: Jumping puts the most pressure on the knees. Climbing puts the least pressure on the knees.

A child who is having trouble reading the bar chart can use a ruler or other straight-edge to trace the level of the column to the numbers on the left side.

Writing in Science

Students will draw lines from the picture to the correct muscle name.

Answer: The name of the muscle you cannot see is the heart muscle.

Puzzle

Answers: The children sitting and lying down are using their heart and lungs; the walking, running and jumping children are using their leg muscles and arm muscles, in addition to their heart and lungs.

Challenge

If students write "arm muscles" for one picture and "leg muscles" for another it would not be incorrect. But, actually, each child is using all of the muscles listed. This should get students thinking.

Answers: Each child is using all of the muscles listed (or any one of them): leg muscles, arm muscles, lungs and heart.

Level B

Main Concept: We need muscles to do work. Muscles can only pull with pairs of muscles working together. Muscles cannot push.

Vocabulary

After writing in the correct words, ask students if they can name other parts of the body that use muscles.

Weekly Lab

Students can try the experiment using different substances in the containers or using three containers rather than just two.

Math

Answers: 1) jumping; 2) climbing; 3) Running puts 300 pounds of pressure more on the knees than climbing. Running puts 600 lbs of pressure on the knees--twice as much pressure (or two times as much) as climbing (300 lbs of pressure).

Students having difficulty with the last question can measure the bar for climbing and mark the spot on the chart that would be twice as much.

Writing in Science

Discuss how muscles react as you work. Ask, "Do your muscles ache when you use them too much? Do your muscles strain more when lifting a heavy weight than they do when lifting a light weight?" Our muscles can ache when they are working very hard. That is the way muscles tell us when they are working hard (or too hard).

Challenge

The child lifting the heavy weight probably has the strongest muscles and the child lying down has tired muscles.

DID YOU KNOW??

Muscles make up 50% of your body weight.

Comprehension

Answer: weights, playground equipment, jump rope, soccer ball

Initiating Questions--Levels C--E

1. Can you see the muscles in your arms?

2. After you pick something up, can your arm just fall down or do you have to think about bringing your arm down?

3. Where else do you think you have muscles?

Follow-up Questions--Levels C--E

4. What do we need to move the parts of our bodies?

5. Do you have to think about your heart to make it beat?

6. What other organs do you think work automatically?

Level C

Main Concept: We need muscles to do work. Muscles can only pull, with pairs of muscles working together, opposite to each other. Some muscles are voluntary and some are involuntary and work automatically.

Vocabulary

Answers: arms, front, heart, involuntary, know, lungs; Strong muscles are good to have.

Weekly Lab

Answers: Students should see chill bumps or goose bumps.

Tiny muscles in the skin control the hair follicles. These are small muscles that react to stimuli like cold or a light touch.

Math

Answer

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Help students plot the values, and then color in the bars using colored pencils or crayons. How will students mark the bar graph for listed values that fall between the lines? Discuss approximation with the students. Advanced students can be encouraged to compare the results and draw conclusions about the relationship between a person's weight and pressure on their knees.

Writing in Science

Large muscles can be seen in arms, legs, neck and abdomen. Some locations of small muscles are the skin, eyes, tongue, face.

Challenge

Answers: waving--wrist muscle; throwing--triceps; singing--vocal cords muscles; bending--spinalis (Actually, waving and throwing probably involve both wrist and triceps muscles. In fact, we use many different muscle groups together all at the same time. Also, students should be able to guess "spinalis" by being familiar with the word spine.)

Puzzle

Some possible answers include: in, ton, ray, not, rot, run, ran, scum, mules, slam, trace, evil, live, try, cream, team, voice, volume, uncle, aunt, mail

Level D

Main Concept: Muscles work by contracting. They can only pull with pairs of muscles working together. Some muscles are voluntary and some are involuntary and work automatically. Muscles contain bands of thick and thin fibers, called filaments.

DID YOU KNOW??

The muscle with the longest name is the sternocleidomastoid muscle.

Vocabulary

Have students try to think of other opposite words that work in pairs.

Weekly Lab

The arm that was pushing against the wall will rise slightly--but noticeably. The muscle continues to contract for a while after contracting for a minute or more. Students may want to repeat this a few times to convince themselves that the action is happening without their effort. The longer and harder the student pushes, the more obvious the reaction will be. Provide other examples and some coaching to ensure they understand the concept.

Math

See Level C--completed bar graph, to the left.

DID YOU KNOW??

Fleas can jump 130 times higher than their own height. If you were a flea and 5 feet tall, you would be able to jump 650 ft in the air more than tenth of a mile.

Writing in Science

Some ideas might be playing a musical instrument, running, catching a ball, sign language, swimming

Comprehension--Where on the Body?

Students should be able to guess correctly, from the names of the muscles, how to place and categorize them. Triceps, wrist, eye, and spinalis are skeletal muscles. Those boxes will be colored blue. The intestinal muscles are smooth muscles. That box will be green. The cardiac muscles control the heart. That box will be colored red.

Puzzle

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Level E

Main Concept: Muscles work by contracting. Bands of filaments in the muscle slide over each other to shorten the muscle. Since muscles can only contract, they must work in pairs. In the arm, the flexor muscle works together with (and opposite to) the extensor muscle. Some muscles are involuntary and work automatically.

Vocabulary

Answers: extensor/flexor; contract/extend; voluntary/involuntary; thick/thin; shortening/ lengthening; push/pull

Ask students to think of other "opposite" words that work in pairs.

Weekly Lab

For this activity, provide a pair of identical empty plastic 2-liter soda bottles. Ahead of time, use a hammer and nail to punch holes near the bottom of one of the bottles. It is harder to blow up a balloon than breathing out because the balloon contains air molecules, which push back as you try to push air in. We can test this hypothesis by comparing the difficulty of blowing into a bottle with trapped air molecules and blowing into a bottle that allows the air molecules in the container to move out of the way. The student should find it much more difficult to blow up the balloon that is in the bottle with no holes. Air molecules are trapped inside the bottle and push against the balloon as the student blows. When there are holes in the bottle, the air molecules can go out as the balloon is expanded and pushes against them.

Math

Answers: 9; 9; 810; 270; 540

This exercise requires students not only to discover the pattern in the table provided, but to apply that pattern to values not in the table. The first question helps the student discover the factor used to arrive at values in the column for jumping. After determining the factor for one set of values, it is checked using a different set of values in the same column. With that information, the student can generate values for that column using any weight. The final two questions guide the students into using the same technique to insert values into any column.

Writing in Science

Our breathing is involuntary while we are sleeping or concentrating on other things. When we take a deep breath to smell flowers or hold our breath to swim under water, we are voluntarily controlling our breathing.

Comprehension--Where on the Body

Answers: A) eye muscles; B) cardiac muscles; C) abdominal muscles; D) vocal cord muscles; E) spinalis muscle; F) biceps muscles; G) hamstring muscles; H) intestinal muscles; I) triceps muscles

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Puzzle

There are many possible variations of correct answers. Throwing, jumping, climbing, marching, and skipping all use leg and arm muscles, But, biceps, triceps, hamstrings, eye muscles, cardiac muscle, spinalis and abdominal muscles all work together for most of these activities, too. The vocal cord muscles may be the only muscles not used in any of these activities. The intestinal muscles are involuntary muscles.

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Pick up an apple. Use one muscle to pick up the apple, Use one muscle to put down the apple. One muscle pulls up, One muscle pulls down. A muscle pulls. A muscle does not push.

Vocabulary

Fill in the missing letters.

a p e

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mu cl s

p l

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p s

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Weekly Lab

Your heart is a muscle. It works hard. You cannot see it. Can you hear it? Let's try.

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You need: a partner, a quiet room, a cardboard tube

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Step 1: Go to a quiet room.

Step 2: Hold the tube up to your partner's chest. Look at the picture to see where.

Step 3: Put your ear next to the other end. Listen.

What did you hear?

Was the heart working hard?

Was the heart beating fast or slow?

Math

Look at the children. They are getting exercise (ex-er-cise).

climbing

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running

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jumping

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Look at the chart. Exercise puts pressure (pres-sure) on the knees,

Which exercise puts the most pressure on the knees?

Which exercise puts the least pressure on the knees?

Writing in Science

WHY FLY shows his muscles, Draw lines to the right muscles.

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* arm muscle

* leg muscle

* heart muscle

Write the name of the muscle in your body you cannot see.

Puzzle

Look at the pictures. Each child is using his muscles. Draw lines from each child to the names of all the muscles he is using.

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* leg muscle

* arm muscle

* lungs

* heart

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Challenge

Look at the names of the muscles in the PUZZLE activity, above. Write the names of the muscles being used next to each picture.

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"What is the smallest thing you can think of?" "Hmm.., a cookie crumb? A grain of sand? A speck of dust?"

"There are things even smaller than that! In our NANOTECHNOLOGY issue, you will learn about things too small to see!"

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Weekly Resources

Helpful Sources for Planning Your Science Weekly Classroom Activities

DID YOU KNOW??

The fastest known muscles are in the vocal cords of birds. No wonder they can make such beautiful songs!

Recommended Resources

* Fitzpatrick, Anne, The Muscles. Smart Apple Media, Minnesota, 2004

* Silverstein, Alvin, The Muscular System. Twenty-First Century Books, New York, 1994

* Simon, Seymour, Muscles: Our Muscular System. Morrow Junior Books, New York, 1998

DID YOU KNOW??

Eye muscles move an average of 100,000 times a day.

Your heart beats about 100,000 times a day.

Internet Resources

Explanation of how muscles work--http://health.howstuffworks.com/muscle.htm/printable

Fun facts about muscles--http://kidshealth.org/kid/htbw/muscles.html

Animated images of the muscle system--http://www.innerbody.com/image/musfov.html

Explanation of muscle types--http://library.thinkquest.org/5777/mus2.htm
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Publication:Science Weekly
Geographic Code:1USA
Date:Feb 3, 2009
Words:2879
Previous Article:Correction.
Next Article:Nanotechnology (Nan-o-tech-nol-o-gy).
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