The structure labeled

"Troponin" is shown situated directly on the myosin heads,

facilitating their attachment to actin.

The

"I band" is depicted as a region containing the Z line and portions

of the thick filaments extending from Z line.

“H zone" represents the region of

the sarcomere containing only thick filaments and the M line

The thin filaments are shown to be

composed solely of actin subunits.

Each individual myosin molecule

illustrated possesses distinct "Actin-binding sites" and an

"ATP-binding site", both located on the heads.

Thick filaments consist of bundled myosin

molecules where the "Heads" project outwards, and these heads are

connected to the myosin "Tail" via a "Flexible hinge

region".