MICROANATOMY

Detailed explanation-1: -The contractile proteins are myosin, the principal component of thick myofilaments, and actin, which is the principal component of thin myofilaments.

Detailed explanation-2: -Myofibrils are bundles of protein filaments that contain the contractile elements of the cardiomyocyte, that is, the machinery or motor that drives contraction and relaxation.

Detailed explanation-3: -They are bound together by perimysium, a sheath of connective tissue, into bundles called fascicles, which are in turn bundled together to form muscle tissue. Myocytes contain numerous specialized cellular structures which facilitate their contraction and therefore that of the muscle as a whole.

Detailed explanation-4: -Each bundle of muscle fiber is called a fasciculus and is surrounded by a layer of connective tissue called the perimysium.