ANATOMY

Detailed explanation-1: -The bipolar thick filament is formed of approximately 300 myosin molecules and their associated proteins (Craig & Offer, 1976; Luther, Munro, & Squire, 1981). It has a strictly uniform dimension of 1.6 µm in length and 15 nm in diameter, which is independent of the type of muscle fiber (Huxley, 1963).

Detailed explanation-2: -Thick filaments are composed of dimers of a remarkable force-generating protein called myosin. Allmyosin molecules have helical tails and globular head groups that hydrolyze ATP and act as motors to move along an actin filament.

Detailed explanation-3: -Each sarcomere consists of a central A-band (thick filaments) and two halves of the I-band (thin filaments).

Detailed explanation-4: -The myofilaments include thick filaments, composed mainly of myosin, and thin filaments composed mainly of actin. The thick and thin filaments cause the cross-striations because of their regular overlap that is kept in register all across the diameter of the muscle fiber. The A-band corresponds to the thick filament.

Detailed explanation-5: -Introduction. Myosin filaments (also called thick filaments) are key components of muscle and non-muscle cells. In striated muscle, they overlap with thin (actin-containing) filaments in an orderly array, making a repeating pattern of sarcomeres, the basic units of contraction [1] (Figure 1a).