Celestine Miller Jeffreys Beethoven Academic Center
25 W. 47th Street
Chicago IL 60609


This mini-teach is designed for middle-school students. Through observation,
demonstration and brainstorming, students will learn the three different types
of muscles and their functions. By building a model of the arm, they will learn
its basic anatomy and how muscles, particularly the bicep and tricep, function
in relationship to bones. Students will perform an experiment on the
relationship between muscle size and muscle fatigue.

Materials Needed:

[for groups of three students]
(10) Pre-prepared wooden upperarm and forearm (humerus, radius & ulna), attached
to each other with (5) hinges; each set containing (4) nails or screws in
anatomically correct positions
(10) Oblong balloons
(5) Markers
(5) Gallon milk jugs filled with water - weight approx. 8 lbs.
(5) Tape measures
(5) Pre-prepared charts
(1) Chicken/cow cardiac, smooth and skeletal muscles
(15) Copies of arm exercises


Visuals: a large "MuscleMania" banner draped across the front of the class and
pictures of weightlifters taped near the students' workstations.

Demonstrate movements that the three types of muscles (cardiac, smooth and
skeletal) enable us to perform. The student-demonstrator will jump up and down
(skeletal-large muscles), frown (skeletal-small muscles), and eat (smooth).
Discuss the continuous beating of the heart (cardiac), and introduce the concept
of voluntary (skeletal) and involuntary (cardiac, smooth) control. Pass around
the chicken/cow cardiac, smooth and skeletal muscles so students can see and
feel the difference between these three types of muscle. Skeletal muscle is
striated, cardiac muscle is somewhat striated and smooth muscle has no
striations. Also observe the anatomical relationship between skin, fat, muscle
and bone. Dispel the myth that muscle can "turn into" fat, or fat into muscle.
Discuss contraction and relaxation and have each student perform different types
of contraction (tonic, isotonic, isometric).

Students will construct an arm, with bones and muscles, using wooden sticks,
balloons and nails. Distribute the "bones" (two 11/2" x 11/2" x 12" sticks
attached by a 180 deg. hinge) to groups of three students. Observe how the
bones move. Attach the balloons, about 50% full of air, to nails/screws in the
bones. Observe where the muscles are attached and how they move with the bones.
Be sure to use the terms origin and insertion. Move the whole apparatus and
observe how the muscles look when they contract and relax. Using the model,
identify terms of movement (abduction, adduction, supination, pronation, flexion
and extension). Add striations with a marker and observe how they change in
appearance with contraction and relaxation.

Now that students have a basic understanding of muscle anatomy, they will
perform an experiment on the relationship of muscle size to muscle fatigue.
Remaining in their groups, students will measure each other's bicep muscle by
making a muscle, palpating the boundaries, and measuring between the boundaries.
Chart the measurement in metric. Then one student will pick up the gallon jug
with his/her dominant hand, hold it by the handle, and lift the jug up and down,
keeping the elbow as close to the waist as possible. To ensure uniformity, the
student will recite, "the rain in Spain stays mainly on the plain"; on "Spain"
lift the weight to the shoulder and on "plain" bring the weight down towards the
thigh. Be sure to tell the students not to rest between flexion and extension.
Muscle fatigue will occur when the person is unable to lift the jug. Another
student will count and chart the number of lifts, and measure the muscle after
exercise. When all the groups have finished charting and exercising, they will
discuss and decide if larger muscles fatigue more or less quickly than smaller
muscles. They should also note the change in muscle size before and after
exercise. Once each group's hypothesis is finalized, come together as a class
and discuss the results. Ask questions concerning factors which make muscles
stronger, e.g. diet, general physical condition, etc. Ask students if they
moved their hips or shoulders while lifting the jug. Also look at the
weightlifters and discuss the concept of size versus strength.

Finally, distribute copies of arm exercises and encourage students to develop
their muscles.

Performance Assessment:

Excellent grasp - this student can define and identify the following terms:
skeletal, cardiac and smooth muscle; involuntary and voluntary control; tendons,
origin and insertion; abduction, adduction, flexion and extension; striation;
tonic, isotonic and isometric. Muscle and fat are not interchangeable. Muscles
are attached to bones and move in relationship to bones. Some muscles contract
and relax synergistically, and cells of the muscles change in appearance.
Muscles fatigue and change in size when a person exercises. Muscle size may/may
not have anything to do with strength.

Fair grasp - this student can define and identify some of the above terms.
Muscles are attached to bones, and they relax and contract. Muscle and fat are
not the same thing. Muscles fatigue and change in size when a person exercises.
Muscle size may/may not have anything to do with strength.

Poor grasp - this student understands that there are different types of muscles.
Muscles move with bones, and relax and contract. Muscles get tired when a
person exercises. Muscle size may/may not have anything to do with strength.


We use muscles when we walk across a room, eat and digest an apple, or simply


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Beattie, S. and Romano, J. "10 foods you should never eat" Muscular Development,
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Boolootian, Richard. Elements of Human Anatomy and Physiology, West Publishing
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Fryyer, M.W. and Neering, I.R. "Actions of caffeine on fast-twitch and slow-
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Lohmeier, Lynne. "We're gonna pump you up" Current Health, v. 19 March 1993;
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Metzger, J.M. and Moss, R.L. "Effects on tension and stiffness due to reduced pH
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Pearce, Richard B. "Fat and muscle" Women's Sports and Fitness, v. 9 July 1987;
pages 36-39.

Phipps, Long and Woods. Medical-Surgical Nursing Concepts and Clinical Practice,
3rd ed. C.V. Mosby, 1987; page 967.

Sheehan, George. "A question of color (American black men's bodies not suited
for marathon running)" Runner's World, v. 23 June 1988; page 14.

Various pictures of exercises and weightlifters from Glamour and Muscular Development, Fitness and Health

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