sliding filaments

sliding filaments [AS, slidan + L, filamentum, thread] , interdigitated thick and thin filaments of a sarcomere. In muscle contraction they slide past each other so that the sarcomere becomes shorter although the filament lengths do not change. The action of the sliding filaments contributes to the increased thickness of a muscle in contraction.

Sliding filaments (Patton and Thibodeau, 2010)