The strongest muscle in the human body is the human heart. The human heart continues to pumps liters of blood throughout the body all lifelong. The minute the heart stops pumping blood, it leads to a heart attack that can prove to be fatal.
Blood Circulation within the Heart for Kids
The human heart is connected with blood vessels coming from around the body. The blood is pumped into the blood vessels through the heart. This pumping of blood goes through a complex process, where in the deoxygenated blood or impure blood is cleansed and oxygenated blood or pure blood is sent throughout the body.
Chambers of the Heart
The heart is divided into two chambers, left and right, the right atrium and ventricle lie on the right side and the left atrium and ventricle on the left side. These two chambers are not directly connected to each other.
Synchronization of the Two Chamber
The right and left side or chambers of the heart work in tandem with each other. Blood from all over the body will reach the heart through pulmonary veins; inferior vena cava and the superior vena cava. The deoxygenated blood will first enter the right atrium and simultaneously the left atrium receives oxygenated blood from the lungs.
Contraction of Atria
The walls of the atria contract and the blood from left and right atria are pumped into the right and left ventricles. The blood from right atrium enters the right ventricle through an open tricuspid valve. When the ventricles are filled with blood, the tricuspid valves close. This helps in prevention of back flow of blood into the atria. In the left atrium, the blood flows to the left ventricle through the mitral valve (bicuspid valve). When the ventricles are full of blood, the mitral valve closes. Again, for the same reason; prevention of blood backflow.
Flow to Lungs
The deoxygenated blood from in the right ventricle is taken to the lungs with the help of pulmonary trunk that arises from the right ventricle. Coronary arteries and the systemic circulation of blood from aorta of left ventricle carry the oxygenated blood from lungs back to heart. The backflow of blood in pulmonary trunk and aorta is prevented due to presence of semilunar valves.
The deoxygenated blood from the heart enters the lungs through the pulmonary valve as seen in the human heart diagram. This process is called pulmonary circulation. From the pulmonic valve, the blood travels to the pulmonary artery into the tiny capillary vessels of the lungs. The oxygen present in the tiny air sacs enters the blood through the walls of the capillaries into the blood. Carbon dioxide, the metabolic waste is passed into the air sacs. As one exhales during respiration, carbon dioxide is removed from the body. The purified blood is oxygenated and sent back to the left atrium through the pulmonary veins.
Circulation into the Body
The oxygenated blood that returns to the heart through the pulmonary vein into the left auricle is passed to the left ventricle through the mitral valve (bicuspid valve). Then the left ventricle pumps the blood into the aorta through systemic circulation. From the aorta, the blood travels to various parts of the body carrying oxygen and nutrients. It then returns back to the heart through the veins in the form of deoxygenated blood. And the cycle of blood flow through the heart continues.
Heart pumps blood continuously without taking a break. There are many such interesting human heart facts. It is very important to maintain a healthy lifestyle as it can affect one's heart. Avoid stress, fatty foods and exercise regularly to keep heart healthy.