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Twitch And Twitch Recruitment Essay

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Nerve and muscle twitch recruitment: External electrode stimulation of a nerve or muscle can lead to a twitch so long as the stimulus voltage is above the muscle or nerve’s threshold value. Electrical stimulation works to open ion channels without the muscle cells, leading to the firing of action potentials. After some time, however, a maximal stimulus voltage will be found. Voltages above this lead to no significant increase in the amplitude of the twitch. Our expectation was that twitch amplitude would increase steadily starting at threshold stimulus and level off at the maximal stimulus. These expectations were based on the results we obtained in previous labs as well as a basic understanding of action potentials, and they were met in this…show more content…
Our findings showed a slight increase in contraction amplitude when the muscle was exposed to 10 mM of caffeine, but a decreased contraction amplitude upon exposure to 20 mM of caffeine (Fig. 6). The duration of contraction did not change at all throughout the experiment. Our results were far from what we expected and forced us to deem our hypothesis incorrect. The results differ from previous studies, which state that exposing skeletal muscle to caffeine increases the duration and strength of contractions by opening calcium ion channels (Olorunshola and Achie 2011). It has also been suggested that caffeine increases contractions be activating the calcium release channels in the sarcoplasmic reticulum of skeletal muscle (Rousseau et al. 1988). In the case of our experiment, it is possible that the muscle was not exposed to caffeine for a duration long enough for proper absorption to occur. Another possible reason for our disagreement with previous studies could be the dosage of caffeine. In the future, the experiment should be performed once more with one or both of these things tweaked in an attempt to find the expected
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