GROSS ANATOMY

Detailed explanation-1: -Chemical and physical interactions between the actin and myosin cause the sarcomere length to shorten, and therefore the myocyte to contract during the process of excitation-contraction coupling. The interactions between actin and myosin serve as the basis for the sliding filament theory of muscle contraction.

Detailed explanation-2: -CARDIAC MUSCLE IS SIMILAR TO OTHER MUSCLE TYPES. Cardiac muscle, like skeletal muscle, is a striated muscle and much of the mechanism of contraction of the two muscle types is similar. Both use the proteins actin and myosin arranged in a highly organized lattice as the basis of the force-generating apparatus.

Detailed explanation-3: -The heart muscle is the myocardium or middle layer of the heart walls. The myocardium is responsible for the contractile function of the cardiac pump.

Detailed explanation-4: -Myosin is an essential component of cardiac muscle, from the onset of cardiogenesis through to the adult heart.