Third Grade - Science - Lesson 14 - Bones and Muscles
Simon Says activity adapted from "Bone Zone" Mailbox Magazine, Oct./Nov. 1997.

Identify bones as the body's means of support.
Count and identify bones in the arm and the leg.
Measure and compare lengths to discover which skeleton facts are true and which false.

Unlabeled skeleton for transparency (attached)
Labeled skeleton transparency (attached)
Two small pieces of masking tape, one marked "U" and one marked "R"
For each group of five students: measuring tape, Find the False Fact chart (attached)

Suggested Books
Ahlberg, Janet and Allan Ahlberg. Funnybones. New York: Morrow, 1981.
Bishop, Pamela. Exploring Your Skeleton: Funny and Not-So-Funny Bones. New York: Franklin Watts, 1991. Wonderful and funny illustrations take the spookiness out of skeletons and bone identification. Reviews information about vertebrates and invertebrates as well.
Ganeri, Anita. Moving. Austin, TX: Raintree/Steck-Vaughn, 1994.
Loredo, Elizabeth. Boogie Bones. New York: Putnam, 1997. Boogie Bones, the skeleton with itchy dancing feet, leaves his graveyard home to go to a dance competition in disguise. This very silly story takes the macabre tone out of looking at skeletons.
Meredith, Susan. What's Inside You? London, Usborne, 1991. A profusely illustrated little paperback that answers questions such as: what color are you inside? (mostly brownish red)
Royston, Angela. The Human Body and How It Works. New York: Random House, 1990.
Sproule, Anna. Body Watch: Know Your Insides. New York: Facts on File, 1987. Includes a very good skeleton illustration with information bubbles pointing to each bone.

To find the name of a bone and see a close-up picture of it, this website has a clickable skeleton. Click on a bone and hear its name.

Teacher's Note
To save time, write the following skeleton facts on the board before class:
1. The length of your radius is equal to the length of your foot.
2. The length of your hand is equal to the length of your foot.
3. The length of your thighbone is equal to 1/4 of your height.
4. Stretch your arms wide. The measurement from fingertips of one hand to fingertips of the other is equal to your height.
To measure height, suggest students stand up against a wall or lie on the floor.

Write How We Move--bones, muscles, brain and nerves on the board. Tell the students that they will be studying how their bodies move--how bones, muscles, brain and nerves work together. Ask the students to stand up and join you in a game of Science Simon Says. Say: Science Simon says as you follow my instructions, think about what makes your body move. In the course of the game, ask the students to touch their toes, reach up high, run in place, touch their ears and clap hands. Finally, ask them to pretend that they have no bones, no skeletons inside them. As they sink to the floor, point out how soft and jellylike these boneless bodies are. Tell the students they remind you of invertebrates. Ask: What are invertebrates? (animals without backbones such as jellyfish and earthworms) Ask: Do invertebrates have skeletons inside their bodies as we have? (no) Have the students return to their seats.
Ask: What do bones do for your body? (Bones hold the body up, give it support.) Show the students the unlabeled skeleton transparency. Point out some of the bones and ask students to identify them, such as backbone, ribs, leg bones, arm bones, skull, etc. Have a student come up and touch his or her toes. Ask: What bones did you use when you touched your toes? (backbone, arm bones, finger bones) Have the student point to them on the transparency. Have the students clap their hands. Ask: What bones did you use when you clapped your hands? (arm bones, finger bones)
Show the students the labeled skeleton transparency. Ask: What are these little bones stacked up to make the backbone called? (vertebrae) Remind the students that vertebrae are like beads on a string, hooked together, but very flexible. Point to the arm of the skeleton Ask: How many bones are there in an arm? (three, one above and two in the lower arm) Ask: What are the names of the three bones? (upper arm bone, radius and ulna) Have the students feel their own arms and see if they can feel two bones, the radius and the ulna, in their lower arms. Have a student come up and stand in the same position as the skeleton on the transparency with palms facing forward. Have another student place the tape labels R and U on the posing student's lower arm to mark which is the ulna and which the radius. Ask the students to look closely at the labeled arm bones because you are going to ask a tricky question. Ask: When you raise your hand, which bone is on the outside, the radius or the ulna? Have the posing student raise his or her hand to demonstrate that the ulna is now on the outside. Ask: How many bones do you count in a leg? (four) Ask: What are the names of these bones? (thighbone, shinbone, fibula and kneecap) Have the students feel their own shinbones and kneecaps. Ask: Looking at the skeleton, which do you think is the biggest bone in the body? (thighbone) Tell the students that arms and legs have long straight bones. Ask: Can you name some bones that are curved? (ribs, jawbone) Have the students feel their ribs. Point out that the ribs form a ribcage. Ask the students to take a deep breath. Ask: What do you think is inside your ribcage? (lungs, heart) Tell the students that some bones such as the ribs, protect soft parts of the body as well as providing support structure. Point to the skull. Ask: What do you think the skull is protecting? (brain) Remind the students that inside the vertebrae or backbone is a bundle of nerves called the spinal cord that carries messages from the brain to the rest of the body. The vertebrae protect the spinal cord. Ask: What is this butterfly-shaped bone called? (pelvis) Tell the students that they have 206 bones in their bodies--long straight bones like the ones in their legs, short bones like vertebrae and the bones in their hands and feet, and flat bones like the ones in their skulls, shoulders and pelvises. These bones work together as a flexible skeleton that supports and protects.
Divide the class into groups of five. Tell the students that there are four skeleton facts on the board. Three of the facts are true and one is false. Armed with only a measuring tape and a chart, they will have to determine which skeleton fact is a false fact. When the groups are finished, have them share their data and conclusions.
Third Grade - Science - Lesson 14 - Bones and Muscles

Possible Homework
Have the students draw pictures of what they would look like if they had no bones.
Rubbery bone activity adapted from The Bones and Skeleton Game Book by Karen Anderson and Stephen Cumbaa.
Demonstrations of joints suggested in "Jazzy Joints" from Integrated Theme Units by Scholastic.

Identify bones that protect soft parts of the body (skull, backbone, ribs).
Observe and diagram the inside of a bone.
Predict what will happen to chicken bones soaked in water and in vinegar.
Classify bone joints as hinge, universal or ball and socket.

Labeled skeleton transparency from previous lesson
Pictures of insides of bones from Suggested Books
For each group of five students: a soup bone, two chicken bones, a hand lens, two jars or other containers, two adhesive labels, a few toothpicks, a 3x5 card
Bottle of white vinegar, pitcher of water
A hinge, ball and socket and universal joint
What Kind of Joint Is This? worksheet (attached)

Suggested Books
Anderson, Karen and Stephen Cumbaa. The Bones and Skeleton Game Book. New York: Workman Pub., 1993. Fun activities, puzzles and amazing facts about the human body.
Balestrino, Philip. The Skeleton Inside You. New York: Scholastic, 1989. Pages 20 and 21 show diagram of the inside of a soup bone.
Barner, Bob. Dem Bones. New York: Chronicle, 1996. Diagrams at the end of the book show 20 different bones.
Johnston, Tony. The Soup Bone. New York: Harcourt, 1990. Digging in her garden for a soup bone, an old woman meets a hungry skeleton.
Kalina, Sigmund. Your Bones Are Alive. New York: Lothrop, 1972. Contains simple line drawings of various bones and an assortment of "try this" activities. "Without a backbone you would collapse. There would be no place to balance your head, no place to hand your arms, and no place to anchor your legs."
Markle, Sandra. Outside and Inside You. New York: Bradbury, 1991. Contains a great close-up photo of inside a bone on page 11.
Novak, Michael. The Glow-in-the-Dark Book of Human Skeletons. New York: Random House, 1997.
Parker, Steve. Brain Surgery for Beginners and Other Major Operations for Minors. Brookfield, CT: Millbrook Press, 1995. This book is loaded with illustrations (including a large one of the inside of a bone), plus very snappy text. The illustration of a person without bones labeled "meaty jelly" is memorable.
Rustean, Jean. The Human Body. New York: Dorling Kindersley, 1993. Illustrations on the cover and title pages show active children and what their skeletons look like in various positions. It is interesting to note the flexibility of the backbone in the pictures of the boy performing a somersault.
Wilkes, Angela. Incredible Skeleton Secrets. New York: Dorling Kindersley, 1994.

Teacher's Note
Soup bones are available at most grocery stores. If not already packaged this way, ask the butcher to slice a soup bone into 1" or 2"-long pieces to reveal the inner structure and marrow. Chicken bones should be from cooked chicken, clean and dry. It generally takes at least three days for the chicken bones to turn rubbery in vinegar. You will want to provide wash up time after working with bones.
Examples of hinge, universal and ball and socket joints are available at hardware stores. Some stores might be willing to let you borrow samples.

Show the students the skeleton transparency from the last lesson. Ask: How do our skeletons help us move? (They give our bodies support.) Ask: Can anyone name three parts of our skeletons that protect soft parts of our bodies? (Skull protects brain; backbone protects spinal cord; ribs protect heart and lungs.) Point to these areas on the skeleton transparency.
Ask: Do you think bones are heavy? Do you think they are the heaviest part of your body? (Accept all answers.) Draw a horizontal chalk line on the board and next to it write 50 lbs. Tell the students that if a person weighs 50 lbs., his or her bones weigh only 7 lbs. Mark off approximately one-seventh of the horizontal line and write 7 lbs. Tell the students that bones make up only one-seventh of a person's body weight. Bones are hard and strong but they are light because they are not solid.
Ask: What is inside bones? (Accept all answers.) Divide the class into groups of five. Ask the students to take a close look at the animal bones they will receive to see what is inside. Ask each group to draw a diagram of the bone and its insides. Distribute the soup bones, hand lenses, and toothpicks for probing. When the students have finished the diagrams, ask them to describe the insides of the bones. Show them pictures of the insides of bones from Suggested Books pointing out the hard, outer layer. Tell the students that, as they have found, many bones are spongy inside with lots of air holes. Bones may have jellylike material called bone marrow inside, too. Bone marrow is where new blood is made.
Hold up a chicken bone and ask: Can bones bend? (No, they are hard and stiff.) Demonstrate that the chicken bone cannot bend. Tell the students that bones are hard and sturdy outside because they are made of crystals of minerals such as calcium. Write calcium on the board. Our bodies get the calcium they need to build sturdy bones from the food we eat. Ask: What foods have calcium in them? (milk, cheese and leafy vegetables) Ask: What do you think would happen to bone if there wasn't enough calcium in your body? (Accept all answers.) Tell the students that to find out what bone would be like with the calcium dissolved away, they will soak chicken bones in two liquids--water and vinegar--for a few days. Remind the students that vinegar is a mild acid. Ask: Do you remember what happened to chalk when we put it in vinegar? (It dissolved.) Distribute containers, chicken bones, labels and 3x5 card to each group. Ask the students to label one container water and the other vinegar. Pour water and vinegar into the labeled containers for each group and ask them to put a chicken bone in each. Ask each group to write a sentence or two on the 3x5 card predicting what they think will happen to the chicken bone in each container. Put the containers in an out-of-the-way spot until next lesson.
Ask the students to stand up, then sit down, then stand up again. Ask them to wave hello and goodbye. Ask them to look to the right and to the left. Have them sit down. Ask: If bones don't bend, how are we able to move? (Accept all answers.) Tell the students that where two bones come together there are joints. Remind the students that the three bones in the arm meet at the elbow. Ask: What are the names of the three bones in the arm? (upper arm bone, radius, ulna) Have the students bend their elbows. Tell the students that the elbow joint moves like a hinge. Show the students the hinge and demonstrate its movement. Bend and unbend your elbow. Tell the students that bones are connected together with stretchy straps called ligaments. There are cushions of soft bone called cartilage between the hard bones to keep them from rubbing together. Write these words on the board. Show the students the universal joint and demonstrate its movement. Tell them that some joints in their bodies work like the universal joint. Show the students the ball and socket joint and demonstrate its movements. Tell the students that other joints in their bodies move in this way. Make a fist and place it in the palm of your other hand and move it around to further demonstrate the action in a ball and socket joint. Ask the students in their groups to find out how joints at knees, head, hands, shoulders fingers, toes, hip move--like a hinge? a universal joint? a ball and socket joint? Distribute the What Kind of Joint Is This? sheet and have students work together to classify body joints. When they are finished, review the results. Have the students stand up once more and ask: What would it be like if we didn't have joints? Have the students follow you on a "walk" (stiff-legged, stiff-armed) around the classroom trying not to bend at any joints.

Third Grade - Science - Lesson 16 - Bones and Muscles

Describe the differences between two treated chicken bones from last lesson.
Predict what might happen to a person with a diet low in calcium.
Describe the roles of ligaments and cartilage.
Create a model x-ray of a hand.

Pictures of elbow and shoulder joints from Suggested Books
An actual x-ray, or if unavailable, a picture of an x-ray from Suggested Books
Illustrations of hand bones from Suggested Books
Black construction paper, white chalk for each student

Suggested Books
Bishop, Pamela. Exploring Your Skeleton: Funny and Not-So-Funny Bones. New York: Franklin Watts, 1991. Includes a great illustration of the bones of the hand, each bone numbered up to 27. Also includes an illustration of ligaments in a knee joint comparing them to stretchy rope, an appropriate analogy, and an illustration of foods that contain calcium.
Cole, Joanna. Your Insides. New York: Putnam, 1992. Written for primary grades, this book has wonderfully appealing illustrations. "Your skeleton is like the frame of a house. Without the frame, a house would fall down. Without bones, you couldn't stand up." Contains illustrations of hinge and ball and socket joints.
Elting, Mary. The Human Body. New York: Macmillan, 1986. Includes illustrations of elbow and hip joints as well as a good overall skeleton illustration with labeled bones on page 57.
Gardner, Robert. Science Projects About the Human Body. Hillside, NJ: Enslow, 1993. While this book is for older children, some of the projects are adaptable to a younger level. The Shrink Test in the homework section of this lesson is one of the projects.
Gross, Ruth Belov. A Book About Your Skeleton. New York: Scholastic, 1978.
Markle, Sandra. Outside and Inside You. New York: Bradbury, 1991. X-rays of adult hand and child's hand are on page 9.
Morgan, Sally. The Human Body. New York: Kingfisher, 1996. Excellent combination of easy- to-read text and do-it-yourself activities. Pages 6 and 7 contain illustrations of various joints and a hinge-wood-and-rubber band elbow.
Parker, Steve. Focus on the Human Body. New York: Gloucester Press, 1993. Pages 6 and 7 show a seated skeleton, x-ray of a hand and various types of joints.
__________. Science Project Book of the Human Body. New York: Marshall Cavendish, 1986. Page 39 includes a hand x-ray and joint comparisons: "The hip is a ball-and-socket joint, just like the joint on a computer joystick."
Royston, Angela. What's Inside My Body? New York: Dorling Kindersley, 1991. Very simple text and lively illustrations make this book more appealing than many more "anatomically correct" books. On page 17 there is a very good illustration of the bones and ligaments of the hand.
Rustean, Jean. The Human Body. New York: Dorling Kindersley, 1993. Features excellent large x-rays of hands, photos of hand bones and good illustrations of knee and shoulder joints.
Silverstein, Alvin and Virginia Silverstein. The Story of Your Hand. New York: Putnam, 1985.
Wyse, Liz. Make It Work! Body. New York: Thomson Learning, 1994. This book is full of projects, some manageable but some requiring a long list of materials and sophisticated cutting equipment.

Have the students examine the chicken bones from the last lesson. Ask: Is the chicken bone soaked in vinegar different from the one soaked in water? How are they different? Make a T-chart on the board with water-soaked on one side and vinegar-soaked on the other. Ask students to describe the textures of the two bones and record the observations on the chart. Remind them that minerals such as calcium are what make bones hard. Ask: What do you think happened to the calcium in the chicken bone soaked in vinegar? (dissolved away) Ask: What do you think might happen to a person's bones if they don't eat enough foods with calcium in them? (They might have soft bones.) Ask: What foods are rich in calcium? (milk, cheese, leafy vegetables)
Remind the students that last lesson they learned about bone joints and how they help us move. Bend and unbend your elbow. Ask: What kind of joint do we have in our elbows? (hinge joint) Have the students bend and unbend their elbows. Have them raise their hands and put them down. Ask: What kind of joint is in your shoulder? (ball and socket joint) Show pictures of elbow and shoulder joints from Suggested Books. Remind them that the stretchy straps that hold the bones together are called ligaments. Ask: What keeps bones from rubbing together at joints? (Cushions of soft bone called cartilage) Ask: Thinking about the two chicken bones, what do you think makes the cartilage soft? (There is less calcium in it.) Where else in our bodies do we have soft bone or cartilage? If the students do not offer these responses, reach up and bend your ears. Tell them that there is cartilage in their ears. Reach up and wiggle your nose. Tell them there is cartilage here, too. Remind the students that sharks and rays have no hard bones in their bodies at all. These fish have skeletons made entirely of cartilage. Have the students wiggle their noses and wiggle their ears to feel the flexibility of cartilage. Have them put their hands on either side of their jaws and open and close their mouths. Ask: Do you feel a hinge joint? Have the students feel their heads and the shape of their skulls. Tell them that the pieces of bone that form their skulls fit together like pieces of a jigsaw puzzle. When they were born, there were spaces between the pieces but now they have grown together.
Ask: Does anyone know where the very smallest bones in the body are located? (inside the ear) Tell the students that there are tiny bones inside each ear that allow them to hear. Ask: What is the biggest bone in the body (thigh bone) Tell them that another name for this biggest bone is femur. Write this word on the board. Remind them that they have measured femurs.
Ask: If someone should break a femur or another bone, what does a doctor do to fix it? Tell the students that first the doctor takes a special picture of the broken bone called an x-ray. An x-ray lets us see right through the skin to the bone underneath. Show the students an x-ray or pictures of x-rays from Suggested Books. Tell them that then the doctor sets the bone so the two broken pieces are pushed together again. Sometimes the doctor will put a cast on the arm or leg or finger to hold the two pieces still. Inside, the bones make new bone cells. The two pieces grow together again. Ask: Do you think bone is alive? (yes) Why? (because it grows and can repair itself)
Show the students illustrations of hand bones or x-rays of hands from Suggested Books. Ask: Are there a lot of bones in your hand? (yes) Tell the students that there are more bones in
their hands than in any other part of their bodies. There are 27 bones in each hand. Ask: How many bones do you have in both hands? (54) What holds the 54 bones of your hands together? (ligaments) Ask the students to bend their fingers. Ask: How many bones do you think are in each finger? (three) Ask the students to, with one hand, touch a thumb to each finger. Ask: How important is your thumb? Divide the class into three groups. Ask one group to pick up a pencil and try to write their names without using their thumbs. Ask another group to try to tie their shoes without using their thumbs. Ask the third group to pick up a book and turn to a certain page without using their thumbs. Ask again: How important is your thumb?
Distribute black construction paper and white chalk to each student. Have the students create x-ray pictures of their hands by tracing their hands and then drawing in the bones. Display the pictures of hand x-rays or illustrations of hand bones from Suggested Books. Remind the students to include the ligaments, the stretchy straps that connect the bones.

Possible Homework
Tell the students that it has been said that we are taller in the morning when we get up than in the evening when we go to bed. Being upright during the day makes vertebrae, knee bones and hip bones settle closer together so we get shorter. At night, when we lie down, they stretch out again. Test to see if this is true. Have someone help you measure your height first thing in the morning and before you go to bed at night for several days. Be sure to measure in the same place each time and in stocking feet. If you have a brother or sister, measure them, too. Make a chart of your findings.

Possible Speakers
Ask a physician or nurse to come speak to the class about setting broken bones and perhaps bring along x-rays, arm sling or modern "cast" bandage.

Third Grade - Science - Lesson 17 - Bones and Muscles

Feel muscles when they are working and at rest.
Locate tendons in the leg, arm and hands.
Observe an involuntary muscle at work.
Identify activities that involve involuntary muscles and those that involve voluntary muscles.

Picture of biceps for transparency (attached)
For each group of five students: one or two hand mirrors
Worksheet for each student (attached)

Suggested Books
Anderson, Karen and Stephen Cumbaa. The Bones and Skeleton Game Book. New York: Workman Pub., 1993. There is an activity on page 22 about muscles and messages from the brain that is very interesting and requires a doorway.
Cole, Joanna. Your Insides. New York: Putnam, 1992. Illustrations of children swimming, biking and drawing show the muscles at work. There is also a good illustration of a bicep working and at rest.
Elting, Mary. The Human Body. New York: Macmillan, 1986. Pictures of the muscular system on page 63 are good but perhaps a bit scary.
Parker, Steve. Brain Surgery for Beginners and Other Major Operations for Minors. Brookfield, CT: Millbrook Press, 1995. Pages 54 and 55 contain excellent illustrations of the muscular system and the tendons of the hand.
Sproule, Anna. Body Watch: Know Your Insides. New York: Facts on File, 1987. On pages 14 and 15 are illustrations of biceps and triceps as well as some of the muscles of the face.

This website features illustrations of how muscles work. It includes pages on flexors and extensors, shoulder muscles, belly muscles and "butt" muscles. Good posture and healthy eating are emphasized.

Teacher's Note
Regarding how the Achilles tendon got its name: Students might remember hearing or reading the story of the Trojan Horse in grade two. Achilles was a great Greek warrior who fought in the Trojan War. When Achilles was a baby, his mother held him by his ankle and dipped him in the River Styx. The special water protected him from harm except for one spot on his ankle where she had held him. Spears and arrows bounced off Achilles. The god Apollo became angry with Achilles and guided an arrow that struck him in the one spot where he could be injured, his heel, and he was killed. Achilles' heel is now an expression that means "weak spot."

Ask: If I said put a hand on your calf muscle, where would that be? Have a student show where the calf is. Ask the students to feel the muscles in their calves while they point their toes upward and then point toes downward. Ask: Do you feel the muscle in your calf? How does the muscle change when you point your toes upward? (It gets hard.) Tell the students that when the muscle is hard, it is working. When it is soft, it is resting. Ask: What is the work that muscles do? (They pull on bones to make them move.) Have the students feel just above their heels. Ask: What do you feel now when you point your toes up and then down? (A stretchy, ropey thing that goes up the back of the calf.) Tell the students that this stretchy, rope-like thing is called a tendon. Write this word on the board. Tendons attach muscles to bones. Ask: What are the other stretchy straps called that hold bones together at joints? (ligaments) Tell the students that while ligaments connect bone to bone, tendons connect skeletons to the muscles that can move them. Tell the students that the tendon they feel above their heels is called the Achilles tendon.
Ask the students to bend their arms at the elbow and "make a muscle." Ask them to feel the upper arm. Tell them that this muscle is called the bicep. Ask: Is the bicep working or resting now? (working) How do you know? (because it is hard) Tell the students that when the muscle is working, it gets shorter. It bunches up as it pulls on the bones of the forearm. Ask: What happens when you unbend your elbow? What happens to the bicep? (It stretches out and rests.) Tell the students that since muscles can pull but cannot push, they have to work in pairs. The bicep's partner muscle is the tricep. The bicep pulls on bones so you can bend your elbow. The tricep muscles pull it back so you can unbend your elbow and straighten your arm. Show the students the transparency of the bicep working. Tell them that bicep means two-headed. Point out that the bicep is connected to the radius in the forearm at one end and has two "heads" or connection points at the other end, one to the upper arm and one to the shoulder blade called the scapula. Ask the students to feel the inside of their elbows as they bend and unbend their arms. Ask: Do you feel tendons working? Tell them that these are the tendons connecting biceps and triceps to arm bones.
Ask the students to look at the backs of their hands while they open and close them. Ask: Do you see any tendons? Where do the tendons go? (from wrist to fingers) Ask the students to turn their hands over, palm up, and continue to open and close them. Ask: Where do you see tendons now? (in the wrist) Ask the students to show where the muscles are that move their hands (in the forearm). Tell the students that the muscles in the forearm pull on tendons that are connected to their fingers. These muscles bend their fingers. Say: Point to some muscles you would use to play piano or guitar? (forearm muscles) Point to muscles you use to touch your nose (biceps). Point to muscles you use to point at me (triceps).
Tell the students that muscles and bones work together to help us move our bodies but they cannot do the job unless they get the message to go on duty. These messages come from the command center of the body. Ask: What is the body's command center? (the brain) Tell the students that nerves are the messengers. They carry electrical messages from brain to muscles to tell them when to get to work. So brain, nerves, muscles and skeleton work together to make our bodies move. Tell the students that they will be studying a lot more about the brain and nerves in upcoming lessons.
Back to muscles, ask: Where in your body do you think you have the largest number of muscles? (Accept all answers.) Have a student volunteer come up. Tell the class to watch the expression of the volunteer. Tell the volunteer to make a happy face, a sad face, an angry face, an I-don't-know-the-answer face, a frightened face. Ask again: Where in your body do you think you have the largest number of muscles? (face) Have the students feel muscles under their cheekbones and on each side of the nose above the lips while they smile. Have them frown and feel the muscles working over their eyes and above the eyebrows.
Tell the students that they have been learning about muscles that work to move bones but there is another kind of muscle, as well. When these muscles work, you are hardly aware of it but if they stopped working, it would be disaster. One of these muscles is inside the rib cage. It works night and day pumping blood throughout the body. Ask: What is the name of this muscle? (heart) Tell the students that the heart is a special kind of muscle called an involuntary muscle. Write this on the board. Tell them that there are involuntary muscles in their skin that cause them to shiver and get goosebumps. There are involuntary muscles in the digestive system that squeeze food through the stomach and intestines.You cannot tell these muscles to work. They are involuntary. Involuntary muscles work whether you want them to or not.
Divide the class into groups of five students and distribute mirrors to each group and worksheets.

Possible Homework
Have the students write questions about bones and muscles based on what they have learned. Collect the best of these questions and write them on bone-shaped slips of paper to use in the Bones and Muscles game in the next lesson.

1. Looking at Face Muscles
Look in the mirror. Smile, frown, make faces! Which muscles can you feel working when you make a sad face? Color in these areas on Face 1. Which muscles are working when you smile? Color in these areas on Face 2.


2. Muscles in Your Mouth
Look in the mirror. Stick out your tongue. The tongue is a group of muscles. See how many ways you can move your tongue. Can you roll it into a tube? Try saying all the vowel sounds and watch your tongue move. How important is this group of muscles in helping you talk? Can you say, "Let's have a glass of lemonade" without using your tongue?

3. Involuntary muscles at work
Look in the mirror and watch the black center or pupil of your eye. Cover your right eye with your hand and count to 20. Take your hand away. What happened to the pupil? You are watching involuntary muscles at work. These muscles open and close the openings in your eyes that let in light.
Put a check next to the activities that use involuntary muscles:
oRunning up a hill
oSitting at the table
oDigesting a cheeseburger
oTalking to a friend
oWatching T.V.

Third Grade - Science - Lesson 18 - Bones and Muscles
Skull Busters activity is adapted from "The Bone Zone" article in Mailbox Magazine, Oct./Nov. 1997.

Review the names of bones and muscles and their locations.
Practice addition and multiplication skills using bone questions.

Unlabeled skeleton transparency from Lesson 14.
Questions written on bone-shaped slips of paper, a hat or bowl
Transparency on which to write skull buster questions

Tell the students that today they will be players in the "Bones-and-Muscles-Know-It-All Olympics." Divide the class into teams for a round of Name That Bone. Show the students the transparency of the unlabeled skeleton to use as a reference. Have two students at a time from each team come up and "pick a bone" from a hat or bowl and try to answer the questions. Keep score on the board. Another approach might be to select a bone picker and a score keeper and open up questions to an entire team.
Possible questions include: What is the largest bone in the body? (thigh bone or femur) Where are the smallest bones in the body found? (inside the ear) What is the soft bone called that is found in the ears and nose? (cartilage) Name a bone in the lower arm. (ulna or radius) Name a curved bone. (rib, jaw) What are the little bones stacked up along the spinal cord called? (vertebrae) What bone protects the brain? (skull) Name a place where new blood is made. (bone marrow) What is the mineral called that keeps bones hard? (calcium) Name a hinge joint in the body. (elbow, knee, finger) Name a ball-and-socket joint in the body. (shoulder, hip) Name a universal joint in the body. (neck) What holds bones together at the joints? (ligaments) Name a food that is rich in calcium. (milk, cheese, spinach, etc.)
Score the round and name a winning team. Tell the students that the second round in the Olympics is called Skull Busters. These are tough questions that might need pencil and paper to figure out. Have all students work on Skull Buster questions and then add up the number of correct answers from each team to keep score. Following are some possible skull buster questions. Write the questions on a transparency for the students' reference. 1. A finger has three bones. A thumb has 2 bones. How many bones in 4 fingers and 1 thumb? 2. How many biceps are in the classroom? 3. There are 32 bones in an arm and a hand. How many bones are in 2 arms and 2 hands?
Tell the students that the final round of the Bones-and-Muscles-Know-It-All Olympics will require one member of each team to come to the front. Tell the contestants that they will be given the name of a bone or muscle. The first one to point to the bone or muscle being named will score. Possible bones and muscles to identify are: skull, shin bone, radius, vertebrae, ribs, thighbone, scapula, bicep, tricep, kneecap, Achilles tendon. Have the students help you tally the final score in the Olympics and declare a winning team.
Remind the students that bone, muscles, ligaments and tendons help us move but that the command center must send the muscles messages. Tell the student that next lesson they will be learning about the command center between their ears--the thinking brain.