Friday, November 7, 2008

UNIT III MUSCLE LAB


For this lab we had to see effects on our muscles doing intervals of exercises, measuring the circumference of the muscle in the upper arm, and affects of temperature. Also, having to feel the muscle in the jaw area and what happens when you grit your teeth. The importance of this lab is to see what actually happens to our muscles while doing different exercises. the picture below shows the things I used during this lab.





In this picture above you see that I have an ice bath for my hand, a measuring tape, the little santa (instead of rubber ball for squeezing), watch (hidden), print out from lab website, and a pen.








BELOW IS THE FORM FROM THE WEBSITE WITH DIRECTIONS ON HOW TO PERFORM THE LAB EXPERIMENTS. I WILL FOLLOW UP WITH A CONCLUSION OF THE RESULTS.



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 32
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Ice Water 20
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his picture above shows me holding my hand in an ice bath for one minute (not fun)!! It was extremely cold.








Effect of Fatigue on Muscle Action

1. Count how many times you can tightly squeeze a rubber ball in your hand
in 20 seconds. Record in Figure 2.

2. Repeat the squeezing nine more times and record results. Do not rest
between trials.

(An alternative procedure which works well is to open and close a
clothespin with the thumb and index finger while the other fingers are held
out straight.)

Figure 2: Effect of Fatigue on muscle action

Trial
# of Squeezes in 20 seconds
9 More X's
1. 44 -53
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2. 40 -49
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3. 36 -45
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4. 34- 43
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5. 32 -41
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6. 30 -39
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7. 28 -37
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8. 26 -35
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9. 24- 33
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10. 22- 31
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These are the results of squeezing santa.







I also observed what happens to your muscle when you measure it flexed and relaxed. I used a measuring tape. The circumference of my upper arm was 9 3/4 and when flexed it was 10 1/2. When you flex your circumference is larger.











ANALYSIS OF DATA:

1. What are the three changes you observed in a muscle while it is working (contracted)?

2. What effect did the cold temperature have on the action of your hand muscles? Explain.




3. What effect did fatigue have on the action of your hand muscles? Explain.




The three changes I observed in the muscle while it was working was that the muscle shorten, get fatigued when worked aggressively, and cold temperature slows the muscle.




The effects of cold water on my hand muscle was extreme. Before submerging my hand in ice waster I had to see how many times I could make a fist in 20 seconds (results above). After having my hand in ice water for one minute I had to see how many time I could make a fist in 20 seconds and the cold water actually slows the muscles down. It was hard to open and close my hand without really trying.




The exercise I did to see how it would effect my muscle was squeezing a rubber ball for 20 seconds and count how many times you could do it. In this case I used santas head because it was just like a rubber ball. My muscles were effected in the same way as the ice water. My hand wanted to stop!! I could not do as many reps as when I first started.




I also did the clenching of my teeth and could feel the muscle protruding outwards. This is the masseter muscle. This muscle is actually the strongest muscle in the body!!! Also, I did the measuring of the muscle using your fingers. When your arm is stretched out you can see a little muscle, but when you flex the muscle actually shortens and gets bigger.


http://www.aacd.com/


This picture shows the masseter muscle.


CONCLUSION:

Muscle contractions are actually due to skeletal muscle and they are attached to our skeleton. Without this we would be unable to walk or talk. Skeletal muscle also allows blood flow. When you go to do any exercise you don't tell your muscle to move, they move voluntarily. The nervous system is what actually gets your muscles to move., sending electrical impulses. A muscle is made up of "muscle cells." As for the cellular level of a muscle contraction; it is energy dependent. That means in order to contract it needs ATP and the release of calcium. I believe that the temperature of cold water and fatiguing the muscles slows down the release of calcium and uses up what ATP has been provided. With excessive exercise, at the cellular level, if oxygen is not used (glycolysis), the glucose turns to lactate. This is fermentation and when this occurs you feel a burning sensation because it turns to lactic acid. The myosin and actin are effected because if no ATP is being made because the glucose didn't continue to the Krebs cycle (etc) then the power stroke will not continue. Myosin relies on ATP for the power stroke. Also if calcium is not released, myosin will not be exposed to the actin binding site.

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