Moreover, we measured the resting length of the muscle. After that, we tie a suture around the tendon and placed it on the femur clamp, and then we placed the stimulating electrodes touched the belly of the muscle, and the stimulating electrodes was attached into the stimulator output panel. We also needed to keep the muscle moist all the time by using frog ringers solution.
Next, we started the first experiment by using the computer and open the program called Libraries.This program allowed us to collect the data from the graph, we stimulated the muscle by increasing the amplitude from 0. 05 volts and increased 0. 1 volts amplitudes each time until it reached 2. 5 volts. In the meanwhile, we would see the voltage stopped changing on the graph, and it indicated it reached plateau, Results: For the first experiment, we found the threshold voltage is around 0.
25 volts, and the plateau started at the point of 2. 2 volts.For the second experiment, we found he summation started at the frequency of GHz, and it reaches tetanus at 64 Hazy. For the third experiment, we calculated the speed of contraction from the graph and it is equal to 12. 44 volts per second, and the speed of relaxation is 3. 89 volts per second. For the fourth experiment, we did not find the optimal length, but we assume the optimal length should be higher than mm.
Discussion: For the first experiment, we increased the O. Volts each time, and we did not get any response until it reach 0. 2 volts, but after that, the response voltage were almost the same at 0. Bob’, 0.
Iv and 0. Iv, and it started to decrease at little, and when it reached 1. 3 v, it started to increase again, but it did not stop. Therefore, we switched the position of the electrodes, and moist the muscle, and do the stimulation start at 2 v, and the response turned out pretty reasonable, and it reached 2. 2 volt, and it did not have too much change, so I assumed it reached the plateau.The main problem would be the position of the electrode is not good, and we took too long time to do the experiment, and the muscle became dry, so we did not get a good data at first.
For the second experiment, the result s pretty clear and we reached the frequency to 64 Hazy, which is high then the lab manual had recommended. For the third experiment, we used the tetanus graph that we conducted from the second experiment, and we used the graph to get the VI-VI value and the time for contraction and relaxation, and we used the formula the change in tension over the time, and we got the number.It was conducted by the helping of our TA (Mega). For the last experiment, we had trouble to adjust the muscle length, because every time we measure the length the electrodes keep moving, therefore the data keep changing in a big range, and t is also hard to adjust the length by 1 mm, because it is too little, and we keep move our hand, and we did not get a good data at the end, and we were running out of time.Therefore, we have the data from other group, and the data was also not compete and the optimal length should be longer then mm, because the response voltage is increasing, but they did not have enough time to finish the experiment. However, in this experiment, we can have a better understand of how muscle contract at a cellular level, and how motor nerve works in the frog legs.