Angila: Unit 3 online lab #2 muscle contrac.

Unit 3 Online Lab #2

In this lab I will demonstrate how temperature and fatigue effect muscle activity. The first activity will show how when muscles are cold they react differently than when at normal room temperature. The second activity represents what happens to muscles as fatigue takes over. The skeletal muscles are very important to daily life without them we would not function. There would be nothing to move our bones and joints resulting in a stationary position at all times. Since our muscles are of great importance it is important to have some understanding of what effects their performance.

Activity 1
This activity demonstrates how at normal temperature I can make 56 strong fists, from an outstretched hand to a tight fist in 20 seconds. The second number was taken after submerging my hand into a bucket of very cold water for a painful minute. Which I then proceeded to make as many complete strong fist as possible in 20 seconds.

Activity 2
For this activity I used a rubber ball filled with air. Every 20 seconds I would record how many times I could squeeze the ball with my fingers. I repeated this a total of 10 times and each time my number of squeezes and/or strength lowered.

1. What are the three changes you observed in a muscle while it is working (contracted)?
The first thing that is noticed is an achy feeling throughout my forearm and desire to stop what I’m doing. You then feel things start to tighten up with small burst of energy but overall an extreme feeling of fatigue. My fingers started to crap the ball was getting heavy and my forearm and hand felt warmer.

2. What effect did the cold temperature have on the action of your hand muscles? Explain. The cold temperature made my muscles react slower, I did not feel tired but I was still restrained from making as tight as a grip I as fast as I wanted to.

3. What effect did fatigue have on the action of your hand muscles? Explain.
Fatigue made the ball seem heavier and my fingers started cramping. It effected how fast I could squeeze the ball every 20 seconds as well as how hard I could squeeze it. With every continuing trail my grip got softer and softer, which kept the repetitions about the same at the end but my strength was gone.

Conclusion

Skeletal muscles help keep a constant body temperature because when they contract ATP (energy) breaks down to be used and it releases heat that is dispersed throughout the body. In this experiment I submerge my hand in cold water which triggered my muscles to contract so that heat would be produce in turn warming my hand up. When I pulled my hand out of the water my fingers were curled up with the muscles contracted making it very difficult to extend and contract into a tight fist. For the second activity I have included a photo showing the process of how muscles contract. Calcium is stored within muscle fiber (cells) in the sarcoplasmic reticulum and when muscles are motivated to move calcium is released to combine with troponin that make myosin binding sites. These sites are where ATP (energy) attached to myosin head combine with the actin and results in a contraction of the muscle. Fatigue takes place because muscle cells store a limited amount of ATP, so the longer I continued contracting muscles the more I used until there was none left and more had to be made. As more was being made my muscle got weaker and slower resulting in fatigue.