The circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels. The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms cardiovascular system and vascular system interchangeably with the circulatory system.
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.
In human anatomy, the inferior mesenteric artery (IMA) is the third main branch of the abdominal aorta and arises at the level of L3, supplying the large intestine from the distal transverse colon to the upper part of the anal canal. The regions supplied by the IMA are the descending colon, the sigmoid colon, and part of the rectum.
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 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 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 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 right marginal vein is a vein of the heart running along the inferior margin of the heart. It drains adjacent region of the right ventricle. It usually opens directly into the right atrium, but may sometimes instead empty into the anterior cardiac veins, or the coronary sinus.
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.
A circulatory anastomosis is a connection between two blood vessels, such as between arteries, between veins or between an artery and a vein. Anastomoses between arteries and between veins result in a multitude of arteries and veins, respectively, serving the same volume of tissue. Such anastomoses occur normally in the body in the circulatory system, serving as back-up routes in a collateral circulation that allow blood to flow if one link is blocked or otherwise compromised, but may also occur pathologically.
The anterior cardiac veins are a variable number of small veins which drain blood from the anterior portion of the right ventricle into the right atrium.
The sinoatrial nodal artery, sinuatrial nodal artery or sinoatrial artery is an artery of the heart which supplies the sinoatrial node, the natural pacemaker center of the heart. It is usually a branch of the right coronary artery. It passes between the right atrium, and the opening of the superior vena cava.
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 left gastric vein is a vein that derives from tributaries draining the lesser curvature of the stomach.
The smallest cardiac veins are small, valveless veins in the walls of all four heart chambers that drain venous blood from the myocardium directly into any of the heart chambers.
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.
