The heart tireless engine of our life

The heart is the tireless engine of our life. It is a muscular organ roughly the size of a closed fist and, in an adult, weighs between 300 and 500 grams. It beats continuously more or less 70 times per minute, pumping the blood in all our body: towards the lungs to fill up with oxygen and towards each cell of the body to carry energy and nutrients.

It is located at the middle of the chest, protected by the rib cage and by a “protective bag” called pericardium. It is slightly to the left, just in between the two lungs.

The heart is formed of four chambers: two atria in the upper part, which collect the incoming blood, and two ventricles in the lower part, which forcefully pump it out. The cardiac valves act as doors that open and close in the right moment, avoiding the blood going back. The coronary arteries instead, are the ones that give oxygen to the heart muscle.

Its activity is double: mechanical, because it contracts (systole) and relaxes (diastole), and electric, because it has and “internal system” that generates and coordinates the heart beats.

Everything starts from a little group of special cells, the sinoatrial node, a real “natural pacemaker” located in the right atrium, that sends electric impulses to all the heart, guaranteeing a synchronized contraction.

In this way, the heart, day and night, carries out the circulation of blood: from the right side to the lungs for oxygenation, from the left side to the body to deliver oxygen and remove waste. A continuous cycle that accompanies us from the first to the last heartbeat.