The heart is divided into two sides; right and left.

How the heart works

Your heart is roughly the size of a fist and sits in the middle of your chest, slightly to the left.

The Heart

It is the best pump in the world which powers your body. It supplies blood carrying oxygen and nutrients to every vital organ in your body. The heart does this all day and all night, all the time. It is located in your chest between your lungs, more to the left, and is protected by your breastbone and ribs. The heart is around the size of your clenched fist.

The heart has two sides; left and right. All the blood returns to the right side and then it is pumped to the lungs. The oxygenated blood returns to the left side of the heart and is pumped out to the vital organs.

The heart is made up of four different zones, two on each side. One is on the top and one is on the bottom. The ones on top are the atria. The heart has a left atrium and a right atrium. The two on the bottom are called the ventricles. The heart has a left ventricle and a right ventricle. The atria and ventricles work as a team.

The left side of the heart delivers oxygenated blood to vital organs. The organs take in the oxygen and nutrients out of the blood then sends to blood filled with waste products (carbon dioxide and others) to the right side of the heart. The right ventricle pumps the blood to the lungs for oxygenation and removal of carbon dioxide. This continues repeatedly.

Blood flow is like the road traffic. It should only flow in one direction. Road traffic is managed by traffic lights and blood flow is managed by valves. Valves are like doors. Doors have a frame, and some have two or three doors. Valves are similar. Valves are between atria and ventricles; tricuspid (right) and mitral (left). There are two more valves; between the right ventricle and pulmonary artery (pulmonary valve) and between the left ventricle and aorta (aortic valve).

Valves can have problems like traffic lights. They can stop working the way they should. Valves can be too tight for blood to enter (stenosis) or too lax that blood backflows (regurgitation).