Keeping 6 quarts of blood flowing through the entire body is hard work. It’s all done at the center of the chest by the heart. This amazing organ is one of the first to develop in babies and works every second of life to allow the body to carry on.
1. Where It’s At
Many people think the heart is on the left side of the body. It is actually located in the center of the chest between the lungs. Since it is soft, it needs protection which it gets from the strong bones of the rib cage.
2. Size of a Heart
You can estimate the size of the heart by holding your hand out and making a fist. For kids, the heart is about the size of a fist. Adult hearts are twice the size of their fist.
3. Four Chambers
The heart includes four chambers, two on each side. On the top are the right and left atriums and the bottom is home to the left and right ventricles. The blood moves up and down through these chambers controlled by valves The word “atrium” is latin for “entrance hall” and “ventricle” means “little belly.”
4. Blood Out
The blood that goes from the heart to other areas of the body travels through arteries. There are two arteries; the aorta from the left ventricle and the pulmonary from the right. The pulmonary artery only carries blood to the lungs while the aorta carries it to arteries that travel the whole body.
5. Blood In
Blood coming to the heart is carried from different parts of the body by veins. Blood from the lungs enters the heart through the left atrium and blood from others parts of the body comes through the right atrium.
6. Aorta – Largest Artery
The largest artery is almost the diameter of a garden hose. It is responsible for carrying blood from the heart to smaller arteries that continue on to other areas of the body. As the arteries travel to areas like the fingers they get smaller. Some are so small that they are only 1/10 of a human hair.
7. The Beat Goes On
The sound heard in a heartbeat is actually two parts. The two valves each make a different sound when they open and close. They work fast to move blood through, it travels at 1 mile per hour. A normal heart beats nearly a hundred thousand times a day.
8. Electric Power
The heart is powered by electricity. This system is called the conduction system. Electric impulses keep the heart muscle moving and can be measured by a test called an EKG. Since this electrical impulse is only used by the heart, it can continue to beat even if it is separated from the body. All it needs is oxygen to keep moving.
9. Boys and Girls
There is a difference between how the heart beats between boys and girls. A girl’s heart actually beats faster than a boy’s. The average boy’s rate of heart beating is 70 times a minute and a girl’s is 78.
10. Hardest Working Muscle
The amazing heart is a muscle that is always working. As a comparison, even when it is resting the heart is working harder than the legs muscles would be while running.