Model Arm

Building a Model Arm

Science Process Skills

Observing

Ordering

Inferring

Materials (per group)

3 cardboard squares (2 squares equal in length to lower arm, 1 square equal to length of upper arm)

tape

large paper clip

two long balloons

string

Adult to help you poke holes for the paper clips

Doing the Activity

FOR THE BONES
Cut 2 cardboard squares equal to the length of your lower arm. Cut 1 cardboard square equal in length to your upper arm.

Roll the cardboard squares tightly, and bind the ends with tape.

Label your rolled squares. Label the one square that was equal to your upper arm -humerus. Label the other two squares-radius and ulna.

FOR THE JOINT
Make a hole through all three "bones" with something sharp. (An adult will need to help with this step.)

Unbend a paperclip. Thread it through the holes. Loop the ends.

FOR THE MUSCLES
Using your tape, attach the radius and ulna together by wrapping tape around the free end of both.

Slightly inflate two long balloons. Tie knots in both ends.

Tie on the balloon muscles. The first muscle will be the biceps. It is attached from the humerus to the radius.

Now tie on the balloon for the triceps. The triceps is attached from the one end of the humerus to the other.

Reflecting

Name the parts of your arm model. Compare the model to your arm.

Bend your arm up and down. Observe the muscles. What happens to the biceps as you move your arm.

This pretend arm has only two muscles. Does a human arm only have two muscles? (No, a human arm has many muscles. The biceps and the triceps work as a team. They work to make opposite actions happen.)

What kind of joint connects the humerus to the radius and ulna? (hinge joint)

Applying

How many different kinds of joints can you find on your body? Where are the different types located?

Draw the bones of the arm in the proper location on your body outline diagram. Label the bones. Draw the muscles attached to the arm. Label the muscles.

What's Happening

There are four kinds of bones in your body. The bones of the arms and legs are called long bones. The bones of your body are connected with different types of joints. The joints allow your body to move in several different ways. The joint at your elbow is called a hinge joint. Connected to your bones are muscles. Muscles contract, or get shorter, to help you move. Muscles work in teams. Every set of muscles has an opposite set of muscles. This helps you to "reverse" or go in the opposite direction.

More Challenges

Dissect a long bone. Visit the butcher at the grocery store and ask them to give you a bone that has been cut in half lengthwise. Look at your bone and see if you can find the following: bits of muscles or tendons, marrow, blood vessels, and tiny holes in the bone for blood vessels.

There are four basic types of bones. Find out what the types are and where they are located.

There are three basic types of muscles. Find out what the types are and where they are located.

There are four kinds of joints. Make a model of type.

Use computer software such as "My Amazing Human Body" "The Magic School Bus Explores the Human Body" to learn more about the heart.

Visit the following web site to learn more about muscles:
http://danke.com/Orthodoc

Activity Source

Allison, Linda. Blood and Guts. Boston, MA: Little, Brown and Company, 1976.

IOWA STATE UNIVERSITY
University Extension

Site contact
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Contact information: Sarah McArdell mcard002@umn.edu
Updated: January, 2000

NNST CYFERNet

	Building a Model Arm
	Science Process Skills Observing Ordering Inferring
	Materials (per group) 3 cardboard squares (2 squares equal in length to lower arm, 1 square equal to length of upper arm) tape large paper clip two long balloons string Adult to help you poke holes for the paper clips
	Doing the Activity FOR THE BONES Cut 2 cardboard squares equal to the length of your lower arm. Cut 1 cardboard square equal in length to your upper arm. Roll the cardboard squares tightly, and bind the ends with tape. Label your rolled squares. Label the one square that was equal to your upper arm -humerus. Label the other two squares-radius and ulna. FOR THE JOINT Make a hole through all three "bones" with something sharp. (An adult will need to help with this step.) Unbend a paperclip. Thread it through the holes. Loop the ends. FOR THE MUSCLES Using your tape, attach the radius and ulna together by wrapping tape around the free end of both. Slightly inflate two long balloons. Tie knots in both ends. Tie on the balloon muscles. The first muscle will be the biceps. It is attached from the humerus to the radius. Now tie on the balloon for the triceps. The triceps is attached from the one end of the humerus to the other.
	Reflecting Name the parts of your arm model. Compare the model to your arm. Bend your arm up and down. Observe the muscles. What happens to the biceps as you move your arm. This pretend arm has only two muscles. Does a human arm only have two muscles? (No, a human arm has many muscles. The biceps and the triceps work as a team. They work to make opposite actions happen.) What kind of joint connects the humerus to the radius and ulna? (hinge joint)
	Applying How many different kinds of joints can you find on your body? Where are the different types located? Draw the bones of the arm in the proper location on your body outline diagram. Label the bones. Draw the muscles attached to the arm. Label the muscles.
	What's Happening There are four kinds of bones in your body. The bones of the arms and legs are called long bones. The bones of your body are connected with different types of joints. The joints allow your body to move in several different ways. The joint at your elbow is called a hinge joint. Connected to your bones are muscles. Muscles contract, or get shorter, to help you move. Muscles work in teams. Every set of muscles has an opposite set of muscles. This helps you to "reverse" or go in the opposite direction.
	More Challenges Dissect a long bone. Visit the butcher at the grocery store and ask them to give you a bone that has been cut in half lengthwise. Look at your bone and see if you can find the following: bits of muscles or tendons, marrow, blood vessels, and tiny holes in the bone for blood vessels. There are four basic types of bones. Find out what the types are and where they are located. There are three basic types of muscles. Find out what the types are and where they are located. There are four kinds of joints. Make a model of type. Use computer software such as "My Amazing Human Body" "The Magic School Bus Explores the Human Body" to learn more about the heart. Visit the following web site to learn more about muscles: http://danke.com/Orthodoc
	Activity Source Allison, Linda. Blood and Guts. Boston, MA: Little, Brown and Company, 1976.