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Q.
For how long, contraction of the muscles continues in sliding filament theory?
Locomotion and Movement
Solution:
Sliding of actin and myosin filaments continues till the $Ca ^{2+}$ ions are pumped back to the sarcoplasmic cisternae, resulting in the masking of actin filaments. This causes the return of $Z$-lines back to their original position, i.e. relaxation of muscle fibre.