Question

Cytological examination of resting and contracted muscle provides important support for the sliding filaments model for how skeletal muscle contracts. this evidence includes the observation that during contraction the

Answer 1

The correct answer is that the H zone becomes narrower.

The H-band refers to the region of the thick filaments, which is not overlaid by the actin (thin filaments). Within the H-zone is a thin M-line, which is formed of cross-connecting components of the cytoskeleton.

At the time of muscle contraction, the A-bands do not vary in their length, whereas the H-zone and the I-bands shorten. This makes the Z-lines come near to each other.