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Left Anterior Descending 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 l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Left Coronary Artery
The left coronary artery (LCA) is a coronary artery that arises from the aorta above the left cusp of the aortic valve, and feeds blood to the left side of the heart muscle. It is also known as the left main coronary artery (LMCA) and the left main stem coronary artery (LMS). Branching The left coronary artery typically runs for 10 to 25 mm, and then bifurcates into the left anterior descending artery (also called the widow maker) and the left circumflex artery. Sometimes, an additional artery arises at the bifurcation of the left main artery, forming a trifurcation; this extra artery is called the ''ramus'' or ''intermediate artery''. The part that is between the aorta and the bifurcation only is known as the left main artery (LM), while the term "LCA" might refer to just the left main, or to the left main and all its eventual branches. A "first septal branch" is sometimes described. Additional images File:Coronary arteries 1.jpg, Left coronary artery File:Cardiac vess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papillary Muscle
The papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves (also known as the mitral and tricuspid valves) via the chordae tendineae and contract to prevent inversion or prolapse of these valves on systole (or ventricular contraction). The papillary muscles constitute about 10% of the total heart mass. Structure There are five total papillary muscles in the heart; three in the right ventricle and two in the left. The anterior, posterior, and septal papillary muscles of the right ventricle each attach via chordae tendineae to the tricuspid valve. The anterolateral and posteromedial papillary muscles of the left ventricle attach via chordae tendineae to the mitral valve.Netter's Atlas of Human Anatomy, plates 216B and 217A Blood supply The mitral valve papillary muscles in the left ventricle are called the anterolateral and posteromedial muscles. * Anterolateral muscle blood supply: left anterior descending ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kevin Smith
Kevin Patrick Smith (born August 2, 1970) is an American filmmaker, actor, comedian, comic book writer, author, YouTuber, and podcaster. He came to prominence with the low-budget comedy buddy film '' Clerks'' (1994), which he wrote, directed, co-produced, and acted in as the character Silent Bob of stoner duo Jay and Silent Bob, characters who also appeared in Smith's later films '' Mallrats'' (1995), ''Chasing Amy'' (1997), ''Dogma'' (1999), '' Jay and Silent Bob Strike Back'' (2001), '' Clerks II'' (2006), ''Jay and Silent Bob Reboot'' (2019), and '' Clerks III'' (2022) which are set primarily in his home state of New Jersey. While not strictly sequential, the films have crossover plot elements, character references, and a shared canon known as the " View Askewniverse", named after Smith's production company View Askew Productions, which he co-founded with Scott Mosier. Since 2011, Smith has mostly made horror films, including '' Red State'' (2011) and the "comedy horror f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tim Russert
Timothy John Russert (May 7, 1950 – June 13, 2008) was an American television journalist and lawyer who appeared for more than 16 years as the longest-serving moderator of NBC's ''Meet the Press''. He was a senior vice president at NBC News, Washington bureau chief and also hosted an eponymous CNBC/MSNBC weekend interview program. He was a frequent correspondent and guest on NBC's ''The Today Show'' and '' Hardball''. Russert covered several presidential elections, and he presented the NBC News/''Wall Street Journal'' survey on the ''NBC Nightly News'' during the 2008 U.S. presidential election. ''Time'' magazine included Russert in its list of the 100 most influential people in the world in 2008. Russert was posthumously revealed as a 30-year source for syndicated columnist Robert Novak. Early life Russert was born in Buffalo, New York, the son of Elizabeth "Betty" (née Seeley; January 9, 1929 – August 14, 2005), a homemaker, and Timothy Joseph "Big Russ" Russert (Novembe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angioplasty
Angioplasty, is also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis. A deflated balloon attached to a catheter (a balloon catheter) is passed over a guide-wire into the narrowed vessel and then inflated to a fixed size. The balloon forces expansion of the blood vessel and the surrounding muscular wall, allowing an improved blood flow. A stent may be inserted at the time of ballooning to ensure the vessel remains open, and the balloon is then deflated and withdrawn. Angioplasty has come to include all manner of vascular interventions that are typically performed percutaneously. The word is composed of the combining forms of the Greek words ἀνγεῖον ' "vessel" or "cavity" (of the human body) and πλάσσω ' "form" or "mould". Uses and indications Coronary angioplasty A coronary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Artery Bypass Surgery
Coronary artery bypass surgery, also known as coronary artery bypass graft (CABG, pronounced "cabbage") is a surgical procedure to treat coronary artery disease (CAD), the buildup of plaques in the arteries of the heart. It can relieve chest pain caused by CAD, slow the progression of CAD, and increase life expectancy. It aims to bypass narrowings in heart arteries by using arteries or veins harvested from other parts of the body, thus restoring adequate blood supply to the previously ischemic (deprived of blood) heart. There are two main approaches. The first uses a cardiopulmonary bypass machine, a machine which takes over the functions of the heart and lungs during surgery by circulating blood and oxygen. With the heart in arrest, harvested arteries and veins are used to connect across problematic regions—a construction known as surgical anastomosis. In the second approach, called the off-pump coronary artery bypass graft (OPCABG), these anastomoses are constructed while t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platelets
Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow or lung, which then enter the circulation. Platelets are found only in mammals, whereas in other vertebrates (e.g. birds, amphibians), thrombocytes circulate as intact mononuclear cells. One major function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site of interrupted endothelium. They gather at the site and, unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium: ''adhesion''. Second, they change shape, turn on receptors and secrete chemical messengers: ''activ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myocardial Infarction
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck or jaw. Often it occurs in the center or left side of the chest and lasts for more than a few minutes. The discomfort may occasionally feel like heartburn. Other symptoms may include shortness of breath, nausea, feeling faint, a cold sweat or feeling tired. About 30% of people have atypical symptoms. Women more often present without chest pain and instead have neck pain, arm pain or feel tired. Among those over 75 years old, about 5% have had an MI with little or no history of symptoms. An MI may cause heart failure, an irregular heartbeat, cardiogenic shock or cardiac arrest. Most MIs occur due to coronary artery disease. Risk factors include high blood pressure, smoking, diabetes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angiography
Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is performed by injecting a radio-opaque contrast agent into the blood vessel and imaging using X-ray based techniques such as fluoroscopy. The word itself comes from the Greek words ἀγγεῖον ''angeion'' 'vessel' and γράφειν ''graphein'' 'to write, record'. The film or image of the blood vessels is called an ''angiograph'', or more commonly an ''angiogram''. Though the word can describe both an arteriogram and a venogram, in everyday usage the terms angiogram and arteriogram are often used synonymously, whereas the term venogram is used more precisely. The term angiography has been applied to radionuclide angiography and newer vascular imaging techniques such as CO2 angiography, CT angiography and MR angiography. The term ''iso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apex Of The Heart
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to the lungs. In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the chest. In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria and lower left and right ventricles. Commonly the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. Fish, in contrast, have two chambers, an atrium and a ventricle, while most reptiles have three chambers. In a healthy heart blood flows one way through the heart due to heart valves, which prevent backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a small amount of fluid. The wall of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myocardium
Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart. The cardiac muscle (myocardium) forms a thick middle layer between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation. It is composed of individual cardiac muscle cells joined by intercalated discs, and encased by collagen fibers and other substances that form the extracellular matrix. Cardiac muscle contracts in a similar manner to skeletal muscle, although with some important differences. Electrical stimulation in the form of a cardiac action potential triggers the release of calcium from the cell's internal calcium store, the sarcoplasmic reticulum. The rise in calcium causes the cell' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
