Muscle Lab

I found this lab to be very interesting for many reasons. I could see how exactly the muscles works in the arm and hand. Muscles are one of those things that most of us take completely for granted. I found out how important muscles are and why we need them. There are two main things a muscle does for us. Firstly, Muscles are the "engine" that your body uses to propel itself. Secondly, It would be impossible for you to do anything without your muscles. Absolutely everything that you conceive of with your brain is expressed as muscular motion. The only ways for a person to express an idea are with the muscles of your larynx, mouth and tongue (spoken words), with the muscles of your fingers (written words or "talking with your hands") or with the skeletal muscles (body language, dancing, running, building or fighting, to name a few).

Muscle Action

1. Place your fingers along the angle of your jaw just in front of your
ear. Grit your teeth and observe what happens to the hardness of the
muscles in your cheek.

2. With the thumb and little finger of one hand, span the opposite arm's
biceps (front muscle of the upper arm) from the elbow to as close to the
shoulder as possible. Bend the arm and observe the change in the length of
the muscle.

3. Wrap a strip of paper around your upper arm and mark the circumference
of your arm on the paper. Clench your fist tightly and mark the new
circumference on the paper. Observe what happens to the circumference of
the muscle.

Effect of Temperature on Muscle Action

1. Count the number of times you can make a fist in 20 seconds. Start with
your hand completely outstretched and make a tight fist each time. Do it
as rapidly as you can. Record the count in Figure 1.

2. Now submerge your hand in a dishpan of water to which has been added
snow or ice so that the temperature is near the freezing point. Leave your
hand in the water for one full minute.

3. Remove your hand and immediately count how many forceful fists you can
make in 20 seconds. Record in Figure 1.

Figure 1: Effect of Temperature on Muscle Action

Temperature
Number of Fists
Normal 51
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Ice Water 37
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Figure 2: Effect of Fatigue on muscle action

Trial
# of Squeezes in 20 seconds
9 More X's
1 46
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2 42
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3 39
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4 35
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5 32
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6 28
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7 25
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8 23----------------------------------------
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9 21
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10 17
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ANALYSIS OF DATA:

1. What are the three changes you observed in a muscle while it is working (contracted)?
From what I observe the three changes would be that the muscle was firms, it was bigger around and the length was longer.

2. What effect did the cold temperature have on the action of your hand muscles? Explain.
In temperture change the colder muscles moved slower and the reaction slowed down quite a bit.

4. What effect did fatigue have on the action of your hand muscles? Explain.
The fatigue of my muscles started to work slow and was resistant to squeezing the ball.

CONCLUSION-
I found this lab to be very fun an entertaining, it was fun to see how the muscles adapted to different situations. That the colder tempature made them struggle to work as well. It was very educational.