\begin{tabular}{l} A smooth, sustained contraction, with no evidence of relaxation, is called \\ O fused, or complete, tetanus \\ O a twitch \\ O sumfused, or incomplete, tetanus \\ \hline\end{tabular}

Complete tetanus, or fused tetanus, refers to a state where muscle fibers are stimulated at a frequency that allows for sustained contraction without any relaxation phase. Imagine your muscles in a never-ending dance party where they simply can’t stop moving—absolutely no chill for those muscle fibers! On the flip side, incomplete tetanus, or unfused tetanus, is when there’s a bit of a break between contractions. Picture a workout playlist where songs overlap but don’t seamlessly transition; there are moments of rest between the high-energy beats. This rollercoaster ride of contraction and relaxation creates a more rhythmic, but still intense, muscular response!