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.
The dark staining area of a sarcomere is the A band, which contains overlapping thick and thin filaments. The A band gives the sarcomere its striated appearance and is involved in muscle contraction.
H zone
A sarcomere is the basic contractile unit of a muscle fiber, consisting of overlapping actin and myosin filaments. It is responsible for muscle contraction by shortening in response to nerve stimulation.
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.
large surface area
Gills are composed of thousands of filaments which are covered in lamellae (only a few cells thick and contain blood capillaries). This creates a large surface area and a short distance for gas exchange.