Lab Two: Muscle Function

Introduction: Welcome to the second lab of the unit. In this lab, I took measurements of my huge muscles, squeezed a ball with a cold hand, and then squeezed it many times in a row. All of this to understand how my muscles work! Enjoy!

For part of the lab, I had to measure my muscle flexed and not flexed. My muscle did not change much in size. :( This is a picture of me taking that measurement.


Then, I had to squeeze a ball for twenty seconds and count the number of squeezes. That information was recorded on a table. Then I submerged my hand in ice water, squeezed again for the same amount of time and recorded that information as well.

Then I squeezed a ball many times in rapid succession to see the effects of muscle fatigue. My special helper, Lady, thought we were playing. I had to tell her this was serious business.

Here is an analysis of my data:

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

The first change I observed was the muscle expanded outward when flexed.

The second change was the muscle shortening, which contributes to the expansion.

The last change was they became tired with repetition.

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

The cold temperature had a numbing effect. For me, this gave relief as I have carpel tunnel problems (actually medically diagnosed, not self diagnosed). It did not slow down the movement for me, as it may have with others. When one has carpel tunnel, the carpel tendon in the wrist inflames with action, putting pressure on surrounding veins and arteries which make blood flow constricted.

Temperature	Number of Fists
Normal	42
Ice Water	42

This is a table of the data collected.

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

Fatigue caused the muscle to react slower as well as causing pain. The muscles are not getting enough oxygen and are using up their ATP energy, which causes the fatigue. The pain is built up because of the acid build up in the muscle.

Trial	Number of Squeezes in 20 Seconds
1	42
2	37
3	38
4	36
5	39
6	36
7	34
8	33
9	33
10	30

This table represents what happened as my muscles became fatigued. I also charted the information.
As you can see, by the graph, my number of squeezes decreased. The numbers on the graph need to be inverted to see the decrease clearly as it starts with 42 and the top is at 30.

Conclusion: At the cellular level, I believe cold and fatigue effect the muscle because of the amount of energy required. The needs to maintain homeostasis in order to continue functioning. When it is cold, it expends energy attempting to warm the area. When it is fatigued, the muscles is using up so much ATP, the cells need to constantly be producing more and more before moving into an anaerobic state that creates cramps!