Like all body organs, the heart needs a supply of blood to bring it oxygen. It cannot get oxygen from the blood within its chambers, which passes through too quickly and under too great a pressure, and in the right side is very low in oxygen. Instead, the muscle that makes up the wall of the heart, the myocardium, receives oxygen-rich blood from a system of small arteries that branch from the aorta. These are called the coronary arteries. They cross over the hearts surface, dividing and sending tiny branches into the heart muscle. The two coronary arteries are no wider than a drinking straw.
The right coronary artery lies in a groove between the right atrium and right ventricle and loops around the lower side and to the rear of the heart like a crown. Hence the name, coronary. This artery supplies blood to the thick muscle of the right ventricle.
On the other side, the left coronary artery divides almost immediately into two large branches, one of which (the anterior descending branch) passes over the front of the heart toward the tip. The other branch (the circumflex branch) lies in a groove between the left atrium and left ventricle. This artery supplies blood to the muscle of the left ventricle. The anterior descending branch supplies the front surface and tip of the heart and the front part of the septum. The circumflex branch supplies the portion of the left ventricular wall away from the septum. From the large coronary vessels, smaller branches arise, which divide and insert into the heart muscle, supplying its nutritional needs. If a blood clot occludes some part of the coronary artery, as in coronary thrombosis or coronary embolism, the cells of the heart are deprived of oxygen and soon die. This is called myocardial infarction. Research Coronary Artery
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Coronary Artery
