MICROANATOMY

Detailed explanation-1: -The primary component of thin filaments is the actin protein. Two other components of the thin filament are tropomyosin and troponin. Actin has binding sites for myosin attachment.

Detailed explanation-2: -The actin filaments are attached at their plus ends to the Z disc, which includes the crosslinking protein -actinin. The myosin filaments are anchored at the M line in the middle of the sarcomere.

Detailed explanation-3: -Thin filaments (or actin filament) are anchored at one end at the Z-band. Titin is anchored to both the Z-band and the M-line. Thick filaments are anchored in the middle of the sarcomere at the M-line.

Detailed explanation-4: -The M-line proteins are always present in existing A-bands. These results suggest that the Z-band and associated structures are responsible for the maintenance of alignment and the lateral register of myofibrils, whereas the M-line is responsible for the structural integrity of the A-band.