Question

if a muscle fiber is overly contracted, the ____ filaments butt against the Z discs

Answer 1

If a muscle fiber is overly contracted, the **thick filaments** (myosin filaments) butt against the Z discs. In a fully contracted state, the thick filaments can push against the Z discs, limiting further contraction and potentially leading to a decrease in force production. This is due to the overlapping of thick and thin filaments (actin filaments) becoming excessive, which restricts further contraction.