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.
A ventricle is one of two large chambers located toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in the upper heart that is smaller than a ventricle. Interventricular means between the ventricles, while intraventricular means within one ventricle.
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 chordae tendineae or tendinous cords, colloquially known as the heart strings, are inelastic cords of fibrous connective tissue that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart.
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 small cardiac vein, also known as the right coronary vein, is a coronary vein that drains parts of the right atrium and right ventricle of the heart. Despite its size, it is one of the major drainage vessels for the heart.
The middle cardiac vein commences at the apex of the heart. It passes posteriorly along the inferior interventricular sulcus to end at the coronary sinus near the sinus' termination.
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 circumflex branch of left coronary artery is a branch of the left coronary artery. It winds around the left side of the heart along the atrioventricular groove. It supplies the posterolateral portion of the left ventricle.
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 posterior interventricular sulcus or posterior longitudinal sulcus is one of the two grooves separating the ventricles of the heart. They can be known as subsinosal interventricular groove or paraconal interventricular groove respectively. It is located on the diaphragmatic surface of the heart near the right margin. It extends between the coronary sulcus and the apex of the heart. It contains the posterior interventricular artery and middle 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 crux cordis or crux of the heart is the area on the lower back side of the heart where the coronary sulcus and the posterior interventricular sulcus meet. It is important surgically because the atrioventricular nodal artery, a small but vital vessel, passes in proximity to the crux of the heart. It is the anastomotic point of right and left coronary artery.
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.
