The heart is a fist-sized muscular organ that works around-the-clock, pumping blood to various parts of the body. It is located between the right and left lungs in the middle of your chest, and is covered by a three-layered, fluid-filled sac called the pericardium.
The heart has four muscular chambers, the upper two chambers are called the right and left atria, and the lower two chambers are called the right and left ventricles. With the help of blood vessels called arteries and veins, the heart and its chambers pump blood, supplying oxygen and nutrients to all parts of the body and collecting carbon dioxide and wastes from the body for purification.
The right atrium collects the de-oxygenated blood from the body from two large veins called the superior and inferior vena cava and delivers it to the right ventricle. This delivery is regulated by three flaps of skin called the tricuspid valve, which allows a one-way direction of blood flow. From here, the blood is pumped to the lungs for purification (oxygenation) via the pulmonary artery. This delivery is regulated by the pulmonary valve.
The left atrium collects the oxygenated blood from the lungs via the pulmonary veins and delivers it to the left ventricle. This delivery is regulated by the mitral valve. The left ventricle then delivers the oxygenated blood to the aorta (main artery) from where it is pumped to the rest of the body. This delivery is regulated by the aortic valve. These main arteries and veins branch out to smaller blood vessels to cover the entire body.
The flow of blood is made possible by the pumping action of the heart’s muscles. These muscles are also supplied with oxygen-rich blood by special blood vessels called coronary arteries, and deoxygenated blood is removed from the muscles by coronary veins. The pumping of the heart follows a specific pattern. This is controlled by an electrical conduction system that triggers the heart walls to contract. The system is made of two sets of conduction cells (nodes) called sinoatrial (SA) node and atrioventricular (AV) node and a series of conduction pathways.
A healthy heart is important for overall well-being. Certain disease conditions and lifestyle habits such as smoking, being overweight, and leading a sedentary life can put your heart at risk affecting how it functions and leading to complications. Heart disease is preventable and the actions you take to reduce your risk of heart disease by making lifestyle changes will increase your chances for a long and healthy life.