Support System: Bones, Joints and Muscles

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Support System Bones, Joints and Muscles

• In this activity you will learn about muscles,
  bones, and other structures that work together to
  allow mechanical motion of your body. All
  animals that have skeletons have similar
  structures. By dissecting a chicken wing, you
  will see how the muscles, tendons, and bones work
  together to make the parts of a chicken wing
  move. You will also learn about some of the
  other structures and functions of the muscular
  and skeletal systems.

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Materials

• For each pair of students
• 1 (raw) chicken wing
• 1 pair of pointed, medium or large dissection
  scissors
• 2 pairs of forceps
• 1 dissecting tray
• paper towels
• 1 toothpick

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Safety

• Only one person may dissect at a time.
• Take turns.
• Keep your fingers out of the way of sharp
  instruments.
• Do not eat or drink in class.
• Be very careful not to touch your mouth, nose, or
  eyes when you are working on the dissection.
• Wash your hands thoroughly with soap and hot
  water after completing the dissection.

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Procedure

1. Draw the diagram of a chicken wing in your
   notebook. Use the diagram to help you locate
   certain muscular and skeletal structures.

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• 2. Locate the following structures in your arm
  shoulder, elbow, and wrist joints two forearm
  bones, one upper arm bone, thumb and finger
  bones.
• 3. Obtain a chicken wing from your teacher. The
  chicken wing has been cleaned with bleach and
  water. Be sure that it is thoroughly dry. Use
  paper towels to make sure it is dry. Place the
  chicken wing in a dissecting tray.
• 4. Examine the whole chicken wing. Without
  cutting yet, feel the wing. Use your fingers to
  find structures on the chicken wing that are
  similar to the human arm structures listed in the
  pictures that follow.

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Bird forelimb
Human forelimb
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• 5. Carefully extend the wing. How many major
  parts does it have? __________
• 6. Examine the skin covering the chicken wing.
  What does it look and feel like?
  __________________________________________________
  __________________________________________________
  ____________________________

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• 7. Turn the wing so the inside is facing up. Use
  your forceps to pinch up the skin, and make a
  small cut with your scissors, as shown in Step A.

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• 8. As shown in Step B, insert a scissor blade
  into the cut so that it is parallel to the bones.
  Be careful that you dont cut through muscle
  under the skin.

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• 9. As shown in Step C, cut the skin, and peel it
  away from the muscle, using your forceps and
  scissors to help you. Do not cut muscle. Expose
  both major joints of the chicken wing. Observe
  the tendons, blood vessels, and muscle. Tendons
  are the shiny strips of tissue that connect
  muscles to bones. Label tendons on your drawing.

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• 10. Notice the yellowish tissue found in small
  clumps on the inside of the skin. This tissue is
  a type of connective tissue called fat. Label fat
  on your drawing.
• 11. Observe the muscles on the chicken wing. The
  muscles are bundles of pale pink tissue that
  surround the bone. There are two groups of
  muscles in the lower arm. Hold down the arm at
  the elbow, and alternatively pull on each muscle
  groups. What happened? _________
  ___________________________
• Which muscles cause the joints to flex
  (bend)? Which muscles extend (straighten) the
  joints? Label flexors and extensors on your
  drawing.

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• 12. Use your forceps to pull on tendons
  individually. When muscles contract, they pull on
  tendons, so when you pull on a tendon, you are
  modeling the action of a wing muscle (Steps D and
  E ).Try to get a part of your chicken wing to
  wave back and forth by pulling on tendons
  attached to two opposing muscles.

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• 13. Examine the joint between the upper wing and
  the lower wing and identify the ligaments. Add
  to and label on your drawing.
• 14. Bend and straighten the joint and observe
  how the bones fit together. The shiny, white
  covering of the joint surfaces is made of
  cartilage. What is the purpose of the cartilage?

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• 15. Cut through the muscles until one of the
  chickens lower wing bones is clearly visible.
• 16. Break the bone with your fingers. Notice how
  resistant the bone was to bending.
• 17. Examine the inside of the chicken bone. Use a
  toothpick to explore the texture of the center of
  the bone, the marrow.
• 18. Set the chicken wing out on the tray so that
  you can see all of the structures.
• 19. Wash your hands thoroughly with soap and hot
  water. Dont touch the chicken after you wash.
• 20. Answer your Analysis and Conclusion
  Questions. You will need to finish them for
  homework.