The heart is not only the body’s strongest muscle, but is also the hardest working muscle in the human body. It’s a hollow, cone-shaped muscle located between the lungs and behind the sternum, or breastbone, and is roughly the size of your fist. The average weight of a male’s heart is 10.5 ounces, while a female’s heart is 9 ounces on the average. This vital organ works nonstop to pump blood filled with oxygen and nutrients through the blood vessels to the body tissues. During an average lifetime, the human heart will beat more than 3 billion times- pumping an amount of blood that equals about one million barrels.

How it works:

The heart consists of four chambers, two atria (upper chambers) and two ventricles (lower chambers). When the heart muscle contracts, or beats, it pumps blood out of the heart. The heart contracts in two stages. In the first stage, the right and left atria contract at the same time, pumping blood into the right and left ventricles. Then the ventricles contract together to push blood out of the heart. Afterwards, the heart relaxes before the next heartbeat so that blood will fill up the heart again.

Functions of the heart:

The right and left sides of the heart have separate functions. The right side of the heart collects oxygen-poor blood from the body and pumps it to the lungs where it picks up oxygen and releases carbon dioxide. The left side of the heart then collects oxygen-rich blood from the lungs and pumps it to the body so that cells throughout the body have the oxygen they need to function properly.

Composed of the heart and blood vessels, the cardiovascular system is responsible for circulating blood throughout the body. A healthy cardiovascular system is vital to supplying the body with oxygen and nutrients.

The heart’s electrical system:

In simple terms, the heart is a pump, made up of muscle tissue. Like all pumps, the heart requires a source of energy to function. The heart’s pumping action comes from a built-in, electrical conductive system. Normally, as the electrical impulse travels through the heart, the heart contracts about 60 to 100 times per minute. The atria contract a fraction of a second before the ventricles so their blood empties into the ventricles before the ventricles contract. Each contraction of the ventricles represents one heartbeat.