Anatomy of the heart
Heart is the main organ responsible for vital processes. Such as nutrition and oxygen supply to the body and
organs. For the simplicity heart can be understood as two separate blood pumps, controlled electrically by
sinoatrial (SA) and atrioventricular (AV) nodes and they are regulated by central nervous system .
Originated electrical impulse at SA node stimulates the atrial muscle causing it to contract and pushes blood
into ventricles. Arrived electrical impulse at the AV node is delayed to allow atria to contract and fill ventricles
of the blood. Then electrical signal continuous to a bundle of nerve fibres called Bundle of His (Figure: left).
Bundle of His continuous down to a left and right bundle branches and terminated at the small fibres called
Purkinje Fibres, which distributes arrived electrical impulse to the heart muscle cells causing ventricular
Left: Hearts electrical conduction path; Right: Hearts cross-section
Heart composed of four chambers; upper two are called atrias, and lower two are called ventricles (Figure: right). Blood flow direction controlled by four valves, permitting forward flow and forbidding backward flow.
Right side of the heart has tricuspid and pulmonic valves, which regulate deoxygenated blood flow returned
from the body and organs. Deoxygenated blood flows to the right atrium and then atria contracts and pushes
blood to the right ventricle. The ventricle contracts and blood flows to the lungs. The left side of the heart has
mitral and aortic valves, which regulate oxygenated blood flow returned from the lungs. Oxygenated blood
flows to the left atrium and then atria contracts and blood flows into a left ventricle. The left ventricle
contracts and again pushes the blood to the body and organs. For the more details see appendix B.