Download Chicken Wing Dissection L

CHAPTER
ADDITIONAL INVESTIGATION
33 Chicken Wing Dissection
Background
The muscular and skeletal systems work together to cause
movement. When skeletal muscles attached to a bone contract,
they pull on that bone. Different muscles can pull bones in opposite
directions. For example, a flexor muscle acts to bend a movable
joint inward. An extensor muscle pulls bone in the opposite
direction to straighten the joint. The coordinated activity of several
diverse muscles allows animals to perform complex movements
like walking, running, swimming, and flying.
In this laboratory exercise, you will dissect a chicken wing. The
dissection will allow you to examine bones, muscles, joints, and
connective tissue.
Problem
What is the internal structure of a bird wing?
MATERIALS
• chicken wing
• dissecting tray
• forceps
• dissecting scissors
PROCESS SKILLS
• Observing
• Inferring
1
Put on a pair of rubber gloves and leave them on for the entire experiment.
2
Examine your wing at the spot where it was cut away from the body. Try to identify
any visible internal structures—muscles, bone, or fat (the yellowish tissue just under
the skin). If a bone has been cut, look inside to see if you can find bone marrow.
3
Look at the diagram of the bones in a chicken wing. Compare your wing to the
diagram, and see if you can feel the bones (and muscle) by gently squeezing various
areas of the wing with your gloved hands.
humerus
radius
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Protection, Support, and Movement
Copyright © by McDougal Littell, a division of Houghton Mifflin Company.
Procedure
ulna
Chicken wing
4
Carefully remove the skin from the outside of the wing. Start by placing your scissors
between the skin and muscle where the wing was removed and then cut toward the
elbow joint. Keep the tip of the scissors up so that you do not cut deep into the wing.
5
When you have reached the elbow joint, make a cut in the skin perpendicular to the one
you have already made (the cuts should form a “T”).
6
Use your forceps to gently peel the skin away, cutting with your scissors as needed.
This might take some time, so be patient.
Additional Investigation
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HUMAN BIOLOGY 73
In the same fashion, remove the skin covering the lower part of the wing (overlying the
radius and ulna).
8
Look for the yellowish tissue under the skin you just removed; this is fat tissue.
9
Now examine the muscles that have been exposed. Draw a picture of the arrangement
of muscles in the wing, using the bone diagram below.
)
Hold the wing down at the shoulder (using gloved hands), and gently pull on each
of the muscles. Note what happens to the wing and the movement that each muscle
causes. Identify which muscle is the extensor for the elbow joint (where the bones
come together) and which is the flexor.
!
Try to find tendons and ligaments. Remember, tendons attach muscle to bone and
ligaments attach bones together at joints. Ligaments will be more difficult to find than
bones; you may have to “dig” and use forceps and scissors to tease tissue away. What
happens if you pull on one of the ligaments?
@
Explore what happens if you cut through a muscle, ligament, or tendon. Note how this
affects joint movement.
#
Find the shiny covering on the surfaces of the ends of the bones in the joint—this
is cartilage. Move the joints back and forth, and take a close look at how the bones
fit together.
$
If you have time, try to identify blood vessels in your chicken wing.
HUMAN BIOLOGY 74
Additional Investigation
McDougal Littell Biology Lab Binder
Copyright © by McDougal Littell, a division of Houghton Mifflin Company.
CHAPTER 33
Protection, Support, and Movement
7
Analyze and Conclude
1. Describe What happened when you pulled on a ligament?
2. Describe How did cutting through a muscle affect movement at the joint?
3. Compare and Contrast Which joint in humans is similar to the joint in the wing of
the chicken where the humerus and radius and ulna come together?
5. Analyze How does cartilage in a joint protect the bone?
6. Predict If a tendon was torn in a live chicken, how would it affect wing movement?
CHAPTER 33
Protection, Support, and Movement
Copyright © by McDougal Littell, a division of Houghton Mifflin Company.
4. Infer What is the function of fat tissue under the skin?
7. Analyze What type of muscle was found in the wing: skeletal, cardiac, or smooth?
Additional Investigation
McDougal Littell Biology Lab Binder
HUMAN BIOLOGY 75