Which region does not contain overlapping thick and thin filaments, located in the center of the thick filament region?

Which region does not contain overlapping thick and thin filaments, located in the center of the thick filament region?

• A. A band
• B. I band
• C. H zone
• D. Z disc

Answer: (C)

In a sarcomere, thick (myosin) and thin (actin) filaments arrange so that overlaps occur in specific regions. The central part of the sarcomere where thick filaments exist without any overlapping thin filaments is the H zone. This zone sits inside the A band and contains only thick filaments, with no actin interaction. The A band covers the full length of the thick filaments and includes overlapping areas with thin filaments; the I band contains thin filaments only and lies next to the Z disc, which marks the sarcomere boundary. So the H zone is the non-overlapping region located at the center of the thick filament region.

In a sarcomere, thick (myosin) and thin (actin) filaments arrange so that overlaps occur in specific regions. The central part of the sarcomere where thick filaments exist without any overlapping thin filaments is the H zone. This zone sits inside the A band and contains only thick filaments, with no actin interaction. The A band covers the full length of the thick filaments and includes overlapping areas with thin filaments; the I band contains thin filaments only and lies next to the Z disc, which marks the sarcomere boundary. So the H zone is the non-overlapping region located at the center of the thick filament region.