The human heart provides a continuous blood circulation through the cardiac cycle and is one of the most vital organs in the human body. It is divided into four chambers: the two upper chambers are called the left and right atria and two lower chambers are called the right and left ventricles. Normally the right ventricle pumps the same blood amount into the lungs with each bit that the left ventricle pumps out. Physicians commonly refer to the right atrium and right ventricle together as the right heart and to the left atrium and ventricle as the left heart.
The heart is one of the most important organs in the entire human body. It is really nothing more than a pump, composed of muscle which pumps blood throughout the body, beating approximately 72 times per minute of our lives.
The human heart is equipped with four types of valves, which prevent the blood flowback between strokes: mitral valve, aortic valve, pulmonic valve and tricuspid valve.
The heart is the body’s engine room, responsible for pumping life-sustaining blood via a 60,000-mile-long (97,000-kilometer-long) network of vessels.
The output of each ventricle per beat is about 70 ml, or about 2 tablespoons. In a trained athlete this amount is about double. With the average heart rate of 72 beats per minute the heart will pump about 5 litres per ventricle, or about 10 litres total per minute. This is called the cardiac output. In a trained athlete the total cardiac output is about 20 litres. If we multiply the normal, non-athlete output by the average age of 70 years, we see that the cardiac output of the average h