Contraction and Relaxation of Cardiac Fibre
Cardiac fibers contract through the process of excitation-contraction coupling which involve the conversion of an electrical stimulus to a mechanical response. In essence, contraction and relaxation help to regulate the flow of blood in the arteries, as well as the flow of the air through the lungs. Contraction involves a precise interaction of contractile proteins, calcium ions, and energy phosphates. Besides, the cardiac fibers relax to return the heart muscles after contraction to the initial conditions. Throughout life, cardiac cycle is significant as it enables the heart to contract 70 times per minute hence supplying five liters of blood to the body.