Coronary circulation is the circulation of blood in the arteries and veins that supply the heart muscle (myocardium). Coronary arteries supply oxygenated blood to the heart muscle. Cardiac veins then drain away the blood after it has been deoxygenated. Because the rest of the body, and most especially the brain, needs a steady supply of oxygenated blood that is free of all but the slightest interruptions, the heart is required to function continuously. Therefore its circulation is of major importance not only to its own tissues but to the entire body and even the level of consciousness of the brain from moment to moment. Interruptions of coronary circulation quickly cause heart attacks, in which the heart muscle is damaged by oxygen starvation. Such interruptions are usually caused by coronary ischemia linked to coronary artery disease, and sometimes to embolism from other causes like obstruction in blood flow through vessels.
The aortic valve is a valve in the heart of humans and most other animals, located between the left ventricle and the aorta. It is one of the four valves of the heart and one of the two semilunar valves, the other being the pulmonary valve. The aortic valve normally has three cusps or leaflets, although in 1–2% of the population it is found to congenitally have two leaflets. The aortic valve is the last structure in the heart the blood travels through before stopping the flow through the systemic circulation.
The papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves via the chordae tendineae and contract to prevent inversion or prolapse of these valves on systole.
A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the main pulmonary artery or pulmonary trunk from the heart, and the smallest ones are the arterioles, which lead to the capillaries that surround the pulmonary alveoli.
The coronary arteries are the arterial blood vessels of coronary circulation, which transport oxygenated blood to the heart muscle. The heart requires a continuous supply of oxygen to function and survive, much like any other tissue or organ of the body.
The atrioventricular node or AV node electrically connects the heart's atria and ventricles to coordinate beating in the top of the heart; it is part of the electrical conduction system of the heart. The AV node lies at the lower back section of the interatrial septum near the opening of the coronary sinus, and conducts the normal electrical impulse from the atria to the ventricles. The AV node is quite compact.
The left coronary artery is a coronary artery that arises from the aorta above the left cusp of the aortic valve, and supplies blood to the left side of the heart muscle. The left coronary artery typically runs for 10–25 mm, then bifurcates into the left anterior descending artery, and the left circumflex artery.
In the blood supply of the heart, the right coronary artery (RCA) is an artery originating above the right cusp of the aortic valve, at the right aortic sinus in the heart. It travels down the right coronary sulcus, towards the crux of the heart. It gives off many branches, including the sinoatrial nodal artery, right marginal artery, posterior interventricular artery, conus artery, and atrioventricular nodal branch. It contributes the right side of the heart, and parts of the interventricular septum.
The interventricular septum is the stout wall separating the ventricles, the lower chambers of the heart, from one another.
The coronary sinus is the largest vein of the heart. It drains over half of the deoxygenated blood from the heart muscle into the right atrium. It begins on the backside of the heart, in between the left atrium, and left ventricle; it begins at the junction of the great cardiac vein, and oblique vein of the left atrium. It receives multiple tributaries. It passes across the backside of the heart along a groove between left atrium and left ventricle, then drains into the right atrium at the orifice of the coronary sinus.
The great cardiac vein is a vein of the heart. It begins at the apex of the heart and ascends along the anterior interventricular sulcus before joining the oblique vein of the left atrium to form the coronary sinus upon the posterior surface of the heart.
The right gastroepiploic artery is one of the two terminal branches of the gastroduodenal artery. It runs from right to left along the greater curvature of the stomach, between the layers of the greater omentum, anastomosing with the left gastroepiploic artery, a branch of the splenic artery.
The coronary sulcus is a groove on the surface of the heart at the base of right auricle that separates the atria from the ventricles. The structure contains the trunks of the nutrient vessels of the heart, and is deficient in front, where it is crossed by the root of the pulmonary trunk. On the posterior surface of the heart, the coronary sulcus contains the coronary sinus. The right coronary artery, circumflex branch of left coronary artery, and small cardiac vein all travel along parts of the coronary sulcus.
In the coronary circulation, the posterior descending artery (PDA), also called the posterior interventricular artery, is an artery running in the posterior interventricular sulcus to the apex of the heart where it meets with the left anterior descending artery also known as the anterior interventricular artery. The PDA supplies the posterior third of the interventricular septum. The remaining anterior two-thirds is supplied by the left anterior descending artery, which is a branch of left coronary artery.
The anterior interventricular sulcus is one of two grooves separating the ventricles of the heart. They can also be known as paraconal interventricular groove or subsinosal interventricular groove respectively. It is situated on the sternocostal surface of the heart, close to the left margin of the heart. It extends between the coronary sulcus, and the apex of the heart; upon reaching the diaphragmatic surface of the heart, it ends at the notch of cardiac apex. It contains the anterior interventricular branch of the left coronary artery, and great cardiac vein.
The right marginal branch of right coronary artery is the largest marginal branch of the right coronary artery. It follows the acute margin of the heart. It supplies blood to both surfaces of the right ventricle.
The left anterior descending artery is a branch of the left coronary artery. It supplies the anterior portion of the left ventricle. It provides about half of the arterial supply to the left ventricle and is thus considered the most important vessel supplying the left ventricle. Blockage of this artery is often called the widow-maker infarction due to a high risk of death.
The atrioventricular nodal branch is a coronary artery that supplies arterial blood to the atrioventricular node, which is responsible for initiating muscular contraction of the ventricles. The AV nodal branch is most often a branch of the right coronary artery.
The left marginal artery is a branch of the circumflex artery, originating at the left atrioventricular sulcus, traveling along the left margin of heart towards the apex of the heart.
The heart is a muscular organ situated in the mediastinum. It consists of four chambers, four valves, two main arteries, and the conduction system. The left and right sides of the heart have different functions: the right side receives de-oxygenated blood through the superior and inferior venae cavae and pumps blood to the lungs through the pulmonary artery, and the left side receives saturated blood from the lungs.
