Sliding filament theory of muscle contraction suggests initiation of an optimum muscle distance associated with maximum stimuli-generated tension. This hypothesis is tried in vitro by measuring muscle tensile receipt to set voltage stimulations under length alterations of the gastrocnemius of genus Xenopus laevis. Muscle length is mechanicall(a)y varied by decrease or extending and an attached force transducer records the tension generated by the fixed stimuli. Our results indicate greatest tensile response of about 3.2 N when muscle length is 30 mm. The response diminishes as deviations from this optimal length increases. These results are consistent with an optimal length of overlap, with associated cross-bridging, amongst actin and myosin filaments in the sarcomere as suggested by slide filament theory.
Introduction
harmonise to the sliding filament theory, (1) and (2), striated muscle contracts when cross-bridges between overlapping myosin (thick) and actin ( skip) filaments create many independent filament micro-slides which result in flinching of the structural unit of the muscle fiber called the sarcomere. Evidence for this sliding theory was first observed in the constancy of the length of the sarcomeres A-band under length variations of the sarcomere.
The A-band has a region where actin and myosin filaments overlap. If all muscle structural components shrank with sarcomere contraction then the A-band should also shrink but this is not observed. Sliding theory was proposed to account for this anomaly.
As the muscle length decreases or increases, the overlapping of thick and thin filaments is increased and decreased respectively. Thus, according to theory, muscle length should be a determinant of active tension generated by striated muscles. Moreover, at that place should be an optimal length because too much sarcomere shrinking will result adjacent filaments of like kind mental block possible actin-myosin cross-bridging. Too much...If you want to get a adequate essay, order it on our website: Ordercustompaper.com
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