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Collateralization
In medicine, collateralization, also vessel collateralization and blood vessel collateralization, is the growth of a blood vessel or several blood vessels that serve the same end organ or vascular bed as another blood vessel that cannot adequately supply that end organ or vascular bed sufficiently. Coronary collateralization is considered a normal response to hypoxia and may be induced, under some circumstances, by exercise. It is considered to be protective. Collateral or anastomotic blood vessels also exist even when blood supply is adequate to an area, and these blood vessels are often taken advantage of in surgery. Some notable areas where this occurs include the abdomen, rectum, knee, shoulder, and head. Coronary collateralization Coronary collateralization exists latently in the normal heart. Microscopic collateral vessels of the heart undergo a process called ''transformation'' that widens the vessel lumen at the expense of its cell wall in response to myocardial stressesâ ... [...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] |
Medicine
Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness. Contemporary medicine applies biomedical sciences, biomedical research, genetics, and medical technology to diagnose, treat, and prevent injury and disease, typically through pharmaceuticals or surgery, but also through therapies as diverse as psychotherapy, external splints and traction, medical devices, biologics, and ionizing radiation, amongst others. Medicine has been practiced since prehistoric times, and for most of this time it was an art (an area of skill and knowledge), frequently having connections to the religious and philosophical beliefs of local culture. For example, a medicine man would apply herbs and say prayers for healing, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Left Main Coronary Artery
The left coronary artery (LCA) is a Coronary arteries, 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 anterior interventricular branch of left coronary artery, left anterior descending artery (also called the Widow maker (medicine), 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 d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitotic Division
In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is maintained. Therefore, mitosis is also known as equational division. In general, mitosis is preceded by S phase of interphase (during which DNA replication occurs) and is often followed by telophase and cytokinesis; which divides the cytoplasm, organelles and cell membrane of one cell into two new cells containing roughly equal shares of these cellular components. The different stages of mitosis altogether define the mitotic (M) phase of an animal cell cycle—the division of the mother cell into two daughter cells genetically identical to each other. The process of mitosis is divided into stages corresponding to the completion of one set of activities and the start of the next. These stages are preprophase (specific to plant cells), prophase, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monocytes
Monocytes are a type of leukocyte or white blood cell. They are the largest type of leukocyte in blood and can differentiate into macrophages and conventional dendritic cells. As a part of the vertebrate innate immune system monocytes also influence adaptive immune responses and exert tissue repair functions. There are at least three subclasses of monocytes in human blood based on their phenotypic receptors. Structure Monocytes are amoeboid in appearance, and have nongranulated cytoplasm. Thus they are classified as agranulocytes, although they might occasionally display some azurophil granules and/or vacuoles. With a diameter of 15–22 μm, monocytes are the largest cell type in peripheral blood. Monocytes are mononuclear cells and the ellipsoidal nucleus is often lobulated/indented, causing a bean-shaped or kidney-shaped appearance. Monocytes compose 2% to 10% of all leukocytes in the human body. Development Monocytes are produced by the bone marrow from precursors cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammatory Response
Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immunity, as compared to adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. bacteria) and compromise the survival of the organism. In contrast, too much inflammation, in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Elastic Lamina
The internal elastic lamina or internal elastic lamella is a layer of elastic tissue that forms the outermost part of the tunica intima of blood vessels. It separates tunica intima from tunica media. Histology It is readily visualized with light microscopy in sections of muscular arteries, where it is thick and prominent, and arterioles, where it is slightly less prominent and often incomplete. It is very thin in veins and venules. In elastic arteries such as the aorta, which have very regular elastic laminae between layers of smooth muscle cells in their tunica media, the internal elastic lamina is approximately the same thickness as the other elastic laminae that are normally present.http://www.ouhsc.edu/histology/text%20sections/cardiovascular.html There is small amount of subendothelial connective tissue between basement membrane of endothelial cells and internal elastic lamina. Reduplication of internal elastic lamina can be seen in elderly individuals due to intimal fib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of anatom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure Gradient
In atmospheric science, the pressure gradient (typically of Earth's atmosphere, air but more generally of any fluid) is a physical quantity that describes in which direction and at what rate the pressure increases the most rapidly around a particular location. The pressure gradient is a dimensional quantity expressed in units of pascal (unit), pascals per metre (Pa/m). Mathematically, it is the gradient of pressure as a function of position. The negative gradient of pressure is known as the force density. In petroleum geology and the petrochemical sciences pertaining to oil wells, and more specifically within hydrostatics, pressure gradients refer to the gradient of vertical pressure in a column of fluid within a wellbore and are generally expressed in pounds per square inch per foot (unit), foot (psi/ft). This column of fluid is subject to the compound pressure gradient of the overlying fluids. The path and geometry of the column is totally irrelevant; only the vertical depth of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Spasm
Coronary reflex is the change of coronary diameter in response to chemical, neurological or mechanical stimulation of the coronary arteries. The coronary reflexes are stimulated differently from the rest of the vascular system. Causes of coronary constriction Chemical * N-nitro L-arginine * indomethacin * glibenclamide * tetraethylammonium chloride * caffeine Other * Cold Causes of coronary dilation Cocaine abuse frequently can cause a coronary spasm, resulting in a spontaneous 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 .... Chemical * Versed (Midazolam): a coronary dilator. In midazolam's presence, dilation was unaffected by N-nitro L-arginine, indomethacin and glibenclamide. * Tetraethylammonium chloride, an inhibitor of the BKCa K+ channel (a high cond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occlusion
Occlusion may refer to: Health and fitness * Occlusion (dentistry), the manner in which the upper and lower teeth come together when the mouth is closed * Occlusion miliaria, a skin condition * Occlusive dressing, an air- and water-tight trauma dressing used in first aid * Vascular occlusion, blockage of a blood vessel ** Vascular occlusion training, or blood flow restriction training, a technique done by some bodybuilders Other uses * Ambient occlusion, a shading method used in 3D computer graphics * Occluded front, part of cyclone formation * Occlusion culling, or hidden surface determination, a 3D computer graphics process * Occlusion effect, an audio phenomenon * Occlusive, in phonetics See also * Occlusion training (other) * Occultation An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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