A human heart consists of four chambers. There are two receiving chambers -- the right atrium and the left atrium. And there are two pumping chambers -- the right ventricle and the left ventricle. Blood enters the heart by way of the two atria (plural of atrium) and is pumped out by the two ventricles. The walls of these chambers are composed of a special type of muscle called cardiac muscle. The ventricles contract approximately once every second in order to pump blood through the blood vessels of the body. That amounts to approximately 32 million contractions in just one year.
In order to produce the energy needed for these contractions, the cardiac muscle uses large quantities of oxygen and nutrients. These nutrients and oxygen must be delivered to the cardiac muscle by a special system of blood vessels. At first glance it might seem that, since the chambers of the heart are full of blood, the cardiac muscle can get all the oxygen and nutrients it needs from the blood inside the chambers. However the distance the nutrients and oxygen can travel is microscopic. And the walls of the chambers, especially the ventricles, are extremely thick. Therefore the walls of the chambers contain a vast network of blood vessels whose purpose is to deliver oxygen and nutrients to the cardiac harga piala muscle. These blood vessels are called coronary vessels.
The aorta is the large blood vessel which leaves the left ventricle to carry blood to all parts of the body. Vessels branching off the aorta are called arteries. At the very beginning of the aorta, the right coronary artery and the left coronary artery branch off the aorta and travel over the outside of the heart. Both of these arteries branch many times to form a network of blood vessels which bring blood to every minute part of the cardiac muscle. That blood is rich in nutrients and oxygen, which the cardiac muscle uses to produce the energy needed to power the contractions of the heart.
If the cardiac muscle does not receive sufficient blood supply, the result could be a heart attack. The usual cause of a heart attack is a "coronary occlusion". The word, coronary, refers to the coronary blood vessels.