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Coronary Circulation
Coronary circulation is the circulation of blood in the blood vessels 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 (myocardial infarctions), 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. Structure Coronary ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circulatory System
The blood 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 (from Greek ''kardia'' meaning ''heart'', and from Latin ''vascula'' meaning ''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''. The network of blood vessels are the great vessels of the heart including large elastic arteries, and large veins; other arteries, smaller arterioles, capillaries that join with venules (small veins), and other veins. The circulatory system is closed in vertebrates, which means that the blood never leaves the network of blood vessels. Some invertebrates such as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Left Ventricle
A ventricle is one of two large chambers 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 (for example the interventricular septum), while intraventricular means within one ventricle (for example an intraventricular block). In a four-chambered heart, such as that in humans, there are two ventricles that operate in a double circulatory system: the right ventricle pumps blood into the pulmonary circulation to the lungs, and the left ventricle pumps blood into the systemic circulation through the aorta. Structure Ventricles have thicker walls than atria and generate higher blood pressures. The physiological load on the ventricles requiring pumping of blood throughout the body and lungs is much greater than the pressure generated by the at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Arteries
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 coronary arteries wrap around the entire heart. The two main branches are the left coronary artery and right coronary artery. The arteries can additionally be categorized based on the area of the heart for which they provide circulation. These categories are called ''epicardial'' (above the epicardium, or the outermost tissue of the heart) and ''microvascular'' (close to the endocardium, or the innermost tissue of the heart). Reduced function of the coronary arteries can lead to decreased flow of oxygen and nutrients to the heart. Not only does this affect supply to the heart muscle itself, but it also can affect the ability of the heart to pump blood throughout the body. Therefore, any disorder or disease of the coro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Marginal Branch Of Right Coronary Artery
The right marginal branch of right coronary artery (or right marginal 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. Structure The right marginal branch is the largest branch to split off from the right coronary artery. It often anastomoses with the nearby parallel posterior interventricular artery, which itself is usually a continuation of the right coronary artery. Variation The right marginal branch may reach the distal part of the posterior interventricular sulcus. Function The right marginal branch primarily supplies the right ventricle A ventricle is one of two large chambers 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 uppe .... Additional images File:Human heart with coronary arter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart Conduction System
The cardiac conduction system (CCS) (also called the electrical conduction system of the heart) transmits the signals generated by the sinoatrial node – the heart's pacemaker, to cause the heart muscle to contract, and pump blood through the body's circulatory system. The pacemaking signal travels through the right atrium to the atrioventricular node, along the bundle of His, and through the bundle branches to Purkinje fibers in the walls of the ventricles. The Purkinje fibers transmit the signals more rapidly to stimulate contraction of the ventricles. The conduction system consists of specialized heart muscle cells, situated within the myocardium. There is a skeleton of fibrous tissue that surrounds the conduction system which can be seen on an ECG. Dysfunction of the conduction system can cause irregular heart rhythms including rhythms that are too fast or too slow. Structure Electrical signals arising in the SA node (located in the right atrium) stimulate the atr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal. Cellular death due to necrosis does not follow the apoptotic signal transduction pathway, but rather various receptors are activated and result in the loss of cell membrane integrity and an uncontrolled release of products of cell death into the extracellular space. This initiates in the surrounding tissue an inflammatory response, which attracts leukocytes and nearby phagocytes which eliminate the dead cells by phagocytosis. However, microbial damaging substances released by leukocytes would cre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Artery Blockage
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic plaque in the arteries of the heart. It is the most common of the cardiovascular diseases. Types include stable angina, unstable angina, myocardial infarction, and sudden cardiac death. A common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw. Occasionally it may feel like heartburn. Usually symptoms occur with exercise or emotional stress, last less than a few minutes, and improve with rest. Shortness of breath may also occur and sometimes no symptoms are present. In many cases, the first sign is a heart attack. Other complications include heart failure or an abnormal heartbeat. Risk factors include high blood pressure, smoking, diabetes, lack of exercise, obesity, high blood cholesterol, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anastomose
An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal (such as the foramen ovale in a fetus's heart) or abnormal (such as the patent foramen ovale in an adult's heart); it may be acquired (such as an arteriovenous fistula) or innate (such as the arteriovenous shunt of a metarteriole); and it may be natural (such as the aforementioned examples) or artificial (such as a surgical anastomosis). The reestablishment of an anastomosis that had become blocked is called a reanastomosis. Anastomoses that are abnormal, whether congenital or acquired, are often called fistulas. The term is used in medicine, biology, mycology, geology, and geography. Etymology Anastomosis: medical or Modern Latin, from Greek ἀναστόμωσις, anastomosis, "outlet, opening", Gr ana- "up, on, upon", stoma "mouth", ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Interventricular Artery
In the coronary circulation, the posterior interventricular artery (PIV, PIA, or PIVA), most often called the posterior descending artery (PDA), is an artery running in the posterior interventricular sulcus to the apex of the heart where it meets with the anterior interventricular artery or also known as Left Anterior Descending artery. It supplies the posterior third of the interventricular septum. The remaining anterior two-thirds is supplied by the anterior interventricular artery which is a septal branch of the left anterior descending artery, which is a branch of left coronary artery. It is typically a branch of the right coronary artery (70%, known as right dominance). Alternately, the PIV can be a branch of the circumflex coronary artery The circumflex branch of left coronary artery, or left circumflex artery or circumflex artery, is a branch of the left coronary artery. Description The left circumflex artery follows the left part of the coronary sulcus, running firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Interventricular Artery
The left anterior descending artery (also LAD, anterior interventricular branch of left coronary artery, or anterior descending branch) is a branch of the left coronary artery. Blockage of this artery is often called the ''widow-maker infarction'' due to a high death risk. Structure It passes at first behind the pulmonary artery and then comes forward between that vessel and the left atrium to reach the anterior interventricular sulcus, along which it descends to the notch of cardiac apex. Although rare, multiple anomalous courses of the LAD have been described. These include the origin of the artery from the right aortic sinus. In 78% of cases, it reaches the apex of the heart. Branches The LAD gives off two types of branches: ''septals'' and ''diagonals''. * Septals originate from the LAD at 90 degrees to the surface of the heart, perforating and supplying the anterior 2/3 of the interventricular septum. * Diagonals run along the surface of the heart and supply the lateral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Sulcus
The coronary sulcus (also called coronary groove, auriculoventricular groove, atrioventricular groove, AV groove) 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. Structure In relation to the rib cage, the coronary sulcus spans from the medial side of the 3rd left costal cartilage, to the middle of the right 6th costal cartilage. Epicardial fat tends to be concentrated along the coronary sulcus. There are two coronary sulci in the heart, including left and right coronary sulci. Left coronary sulcus The left coronary sulcus originates posterior to the pulmonary trunk, and travels inferiorly separating the left atrium and left ventricle. The location of the left coronar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumflex Branch Of Left Coronary Artery
The circumflex branch of left coronary artery, or left circumflex artery or circumflex artery, is a branch of the left coronary artery. Description The left circumflex artery follows the left part of the coronary sulcus, running first to the left and then to the right, reaching nearly as far as the posterior longitudinal sulcus. There have been multiple anomalies described, for example the left circumflex having an aberrant course from the right coronary artery. Branches The circumflex artery curves to the left around the heart within the coronary sulcus, giving rise to one or more left marginal arteries (also called obtuse marginal branches) as it curves toward the posterior surface of the heart. It helps form the posterior left ''ventricular branch'' or posterolateral artery. The circumflex artery ends at the point where it joins to form to the posterior interventricular artery in 15% of all cases, which lies in the posterior interventricular sulcus. In the other 85% of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
