Please answer the following question: Answer the following question given this paragraph: When a sarcomere shortens, some regions shorten whereas others stay the same length. A sarcomere is defined as the distance between two consecutive Z discs or Z lines; when a muscle contracts, the distance between the Z discs is reduced. The H zonethe central region of the A zonecontains only thick filaments and is shortened during contraction. The I band contains only thin filaments and also shortens. The A band does not shortenit remains the same lengthbut A bands of different sarcomeres move closer together during contraction, eventually disappearing. Thin filaments are pulled by the thick filaments toward the center of the sarcomere until the Z discs approach the thick filaments. The zone of overlap, in which thin filaments and thick filaments occupy the same area, increases as the thin filaments move inward. Q: The distance between two consecutive z discs or z lines is called what? Choices: - contractile - ligule - radius - sarcomere A:
Answer:
sarcomere