A-band. It has actin (thin protein) and myosin (thick protein) overlapping within it
The area of the sarcomere containing the thick filaments is known as the A band. It appears dark under a microscope due to the overlapping thick filaments. The A band also includes some thin filaments at its edges where they overlap with the thick filaments.
This area is the A band of a sarcomere, which contains both thick myosin filaments and thin actin filaments. The overlapping of these filaments is essential for muscle contraction to occur through the sliding filament mechanism.
It is a section of the Sarcomere that stretches from one end of the Myosin filament to the other, and also includes parts of the Actin filaments that overlaps it.
H zone
A sarcomere consists of thin and thick filaments arranged so they can slide over each other. The boundary of the sarcomere are the Z lines. Thin filaments extend from the Z lines and overlap with thick filaments in the middle of the sarcomere. The I band is on each side of the Z line where only thin filaments occur. The A band is the length of the thick filaments and is divided into three parts; the zone of overlap is on each end where thin and thick filaments occur, the H band is in the middle and has only thick filaments, and the M line is the center of the A band.
The region of the sarcomere that contains both actin and myosin is called the A band. This area appears dark under a microscope and encompasses the length of the thick myosin filaments, as well as overlapping thin actin filaments. The A band is crucial for muscle contraction, as the sliding of actin over myosin occurs in this region during the contraction process.
When sarcomeres shorten during muscle contraction, the I band and H zone both decrease in length. The I band, which contains only thin filaments, shortens as the thick filaments slide past them. The H zone, which is the area of the A band that contains only thick filaments, also diminishes as the thick filaments overlap more with the thin filaments. Overall, the A band remains the same length, while the I band and H zone decrease.
Stratum Spinosum The Stratum Spinosum is several cell layers thick. These cells contain a weblike system of intermediate filaments, mainly tension-resisting bundles of pre-keratin filaments, which span thir cytosol to attach to desmosomes.
During contraction, the H zone and I band shorten while the A band remains the same length. The A band is the dark band in the sarcomere that contains the thick filaments, the I band is the light band composed of thin filaments, and the H zone is the area in the center of the sarcomere where only thick filaments are present.
H band
You think probable to the overlapping area.
It's the I Band.