Twitch Recruitment Experiment

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Twitch recruitment: As stimulus voltage increased contraction force increased until it plateaued at the stimulus voltage of 120 mV (Fig 1A) As stimulus voltage increased contraction force increased. (Fig 1B). Our results are consistent with the current knowledge of twitch recruitment in skeletal muscles. As the stimulus voltage increase, more motor units were activated increasing contraction force. Our results mean that that function organism’s skeletal muscles are able to recruit motor units to make large powerful body movements.
Skeletal muscle length-tension relationship: The maximum contraction force, 0.8102 N, was recorded when the gastrocnemius muscle was stretched by 2 mm. As the gastrocnemius muscle was stretched past 2 mm the contraction
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At 20 Hz the contraction forces of the peaks and troughs, 1.410033 + 0.142475 N (N=3) and 1.4029 + 0.124279 N (N=3), respectively, did not significantly differ. As the frequency of stimulation increased past 20 Hz the contraction forces of the peaks and troughs continued to not significantly differ (Fig 4). Our results were in agreement with the current knowledge of tetanus. At a high enough frequency the muscles was not able to relax between contractions. Thus, that is why there were no significant differences in peaks and troughs at 20 Hz. Our results mean that stimulating skeletal muscles at high enough frequencies results in no relaxation between muscle contractions in functioning organisms. Severe injury or death may occur from tetanus.
Skeletal muscle fatigue: At the high stimulus frequency of 2 Hz the contraction force decreased 3.25% per second. Our results were in agreement with the current knowledge of muscle fatigue. Fatigue was partly due to the loss of energy resources. As skeletal muscle was stimulated at high frequencies, the energy resources became depleted. Our results mean that continuously stimulated skeletal muscles in functioning organisms, eventually lead to fatigue limiting muscle
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We did see what we expected, the contraction force (N) after the addition of hot (50°C) treatment was significantly larger than both of the contraction forces after the cold (4° C) and room temperature (22°C) treatments. There was no significant difference between the contraction forces after the cold and room temperature treatments (Fig 5A). The contraction duration (s) after the cold treatment was significantly longer than both of the contraction durations after the room temperature and hot treatments. The contraction duration after the room temperature treatment was significantly longer than the contraction duration after the hot treatment (Fig 5B). Our results mean that as body temperature increases in organisms, contraction force of skeletal muscle decrease. In contrast, as body temperature decreases in organisms, contraction force decrease in skeletal. Our finding were consistent with a study that showed the contraction force increased and contraction duration decrease with increasing temperature. The researchers contributed these results to regulation of acetylcholine release by temperature. As temperature increases, release of acetylcholine increases. In contrast as temperature decreases, release of acetylcholine decreases (Foldes et al. 1978). An additional study was also consistent with our results, contributing

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