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Shunt (medical)
In medicine, a shunt is a hole or a small passage that moves, or allows movement of, fluid from one part of the body to another. The term may describe either congenital or acquired shunts; acquired shunts (sometimes referred to as iatrogenic shunts) may be either biological or mechanical. __TOC__ Types * Cardiac shunts may be described as right-to-left, left-to-right or bidirectional, or as systemic-to-pulmonary or pulmonary-to-systemic. * Cerebral shunt: In cases of hydrocephalus and other conditions that cause chronic increased intracranial pressure, a one-way valve is used to drain excess cerebrospinal fluid from the brain and carry it to other parts of the body. This valve usually sits outside the skull but beneath the skin, somewhere behind the ear. Cerebral shunts that drain fluid to the peritoneal cavity (located in the upper abdomen) are called ''ventriculoperitoneal'' (''VP'') shunts. * Lumbar-peritoneal shunt (a.k.a. ''lumboperitoneal'', ''LP''): In cases of chron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phonocardiograms From Normal And Abnormal Heart Sounds
Auscultation (based on the Latin verb ''auscultare'' "to listen") is listening to the internal sounds of the body, usually using a stethoscope. Auscultation is performed for the purposes of examining the circulatory and respiratory systems (heart and breath sounds), as well as the alimentary canal. The term was introduced by René Laennec. The act of listening to body sounds for diagnostic purposes has its origin further back in history, possibly as early as Ancient Egypt. (Auscultation and palpation go together in physical examination and are alike in that both have ancient roots, both require skill, and both are still important today.) Laënnec's contributions were refining the procedure, linking sounds with specific pathological changes in the chest, and inventing a suitable instrument (the stethoscope) to mediate between the patient's body and the clinician's ear. Auscultation is a skill that requires substantial clinical experience, a fine stethoscope and good listening ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Alveolus
A pulmonary alveolus (plural: alveoli, from Latin ''alveolus'', "little cavity"), also known as an air sac or air space, is one of millions of hollow, distensible cup-shaped cavities in the lungs where oxygen is exchanged for carbon dioxide. Alveoli make up the functional tissue of the mammalian lungs known as the lung parenchyma, which takes up 90 percent of the total lung volume. Alveoli are first located in the respiratory bronchioles that mark the beginning of the respiratory zone. They are located sparsely in these bronchioles, line the walls of the alveolar ducts, and are more numerous in the blind-ended alveolar sacs. The acini are the basic units of respiration, with gas exchange taking place in all the alveoli present. The alveolar membrane is the gas exchange surface, surrounded by a network of capillaries. Across the membrane oxygen is diffused into the capillaries and carbon dioxide released from the capillaries into the alveoli to be breathed out. Alveoli are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfusion
Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion is measured as the rate at which blood is delivered to tissue, or volume of blood per unit time (blood flow) per unit tissue mass. The SI unit is m3/(s·kg), although for human organs perfusion is typically reported in ml/min/g. The word is derived from the French verb "perfuser" meaning to "pour over or through". All animal tissues require an adequate blood supply for health and life. Poor perfusion (malperfusion), that is, ischemia, causes health problems, as seen in cardiovascular disease, including coronary artery disease, cerebrovascular disease, peripheral artery disease, and many other conditions. Tests verifying that adequate perfusion exists are a part of a patient's assessment process that are performed by medical or emergency personnel. The most common methods include eva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Shunt
A pulmonary shunt is the passage of deoxygenated blood from the right side of the heart to the left without participation in gas exchange in the pulmonary capillaries. It is a pathological condition that results when the alveoli of parts of the lungs are perfused with blood as normal, but ventilation (the supply of air) fails to supply the perfused region. In other words, the ventilation/perfusion ratio (the ratio of air reaching the alveoli to blood perfusing them) of those areas is zero. A pulmonary shunt often occurs when the alveoli fill with fluid, causing parts of the lung to be unventilated although they are still perfused. Intrapulmonary shunting is the main cause of hypoxemia (inadequate blood oxygen) in pulmonary edema and conditions such as pneumonia in which the lungs become consolidated. The shunt fraction is the percentage of cardiac output that is not completely oxygenated. In pathological conditions such as pulmonary contusion, the shunt fraction is significant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Edema
Pulmonary edema, also known as pulmonary congestion, is excessive liquid accumulation in the tissue and air spaces (usually alveoli) of the lungs. It leads to impaired gas exchange and may cause hypoxemia and respiratory failure. It is due to either failure of the left ventricle of the heart to remove oxygenated blood adequately from the pulmonary circulation (cardiogenic pulmonary edema), or an injury to the lung tissue directly or blood vessels of the lung (non-cardiogenic pulmonary edema). Treatment is focused on three aspects: firstly improving respiratory function, secondly, treating the underlying cause, and thirdly preventing further damage and assuring full recovery to the lung. Pulmonary edema, especially when sudden (acute), can lead to respiratory failure or cardiac arrest due to hypoxia. It is a cardinal feature of congestive heart failure. The term edema is from the Greek (''oidēma'', "swelling"), from οἰδέω (''oidéō'', "(I) swell"). Types Classical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disseminated Intravascular Coagulation
Disseminated intravascular coagulation (DIC) is a condition in which blood clots form throughout the body, blocking small blood vessels. Symptoms may include chest pain, shortness of breath, leg pain, problems speaking, or problems moving parts of the body. As clotting factors and platelets are used up, bleeding may occur. This may include blood in the urine, blood in the stool, or bleeding into the skin. Complications may include organ failure. Relatively common causes include sepsis, surgery, major trauma, cancer, and complications of pregnancy. Less common causes include snake bites, frostbite, and burns. There are two main types: acute (rapid onset) and chronic (slow onset). Diagnosis is typically based on blood tests. Findings may include low platelets, low fibrinogen, high INR, or high D-dimer. Treatment is mainly directed towards the underlying condition. Other measures may include giving platelets, cryoprecipitate, or fresh frozen plasma. Evidence to supp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varices
A varix (pl. varices) is an abnormally dilated vessel with a tortuous course. Varices usually occur in the venous system, but may also occur in arterial or lymphatic vessels. Examples of varices include: * Varicose veins, large tortuous veins usually found on legs * Sublingual varices * Esophageal varices, commonly stemming from cirrhosis of the liver, also known as oesophageal varicose * Gastric varices, commonly stemming from cirrhosis of the liver * Intestinal varices * Scrotal varices * Vulvar varices * Pelvic varices * Vesical varices, varicose veins associated with the urinary bladder * Rectal varices, which can be similar to external haemorrhoids See also * Varicose ulcer * Varix (mollusc) A varix () is an anatomical feature of the shell of certain sea snails, marine gastropod molluscs. Gastropods whose shells have varices are primarily families and species within the taxonomic groups Littorinimorpha and Neogastropoda. The va ... References {{Reflist Diseases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascites
Ascites is the abnormal build-up of fluid in the abdomen. Technically, it is more than 25 ml of fluid in the peritoneal cavity, although volumes greater than one liter may occur. Symptoms may include increased abdominal size, increased weight, abdominal discomfort, and shortness of breath. Complications can include spontaneous bacterial peritonitis. In the developed world, the most common cause is liver cirrhosis. Other causes include cancer, heart failure, tuberculosis, pancreatitis, and blockage of the hepatic vein. In cirrhosis, the underlying mechanism involves high blood pressure in the portal system and dysfunction of blood vessels. Diagnosis is typically based on an examination together with ultrasound or a CT scan. Testing the fluid can help in determining the underlying cause. Treatment often involves a low-salt diet, medication such as diuretics, and draining the fluid. A transjugular intrahepatic portosystemic shunt (TIPS) may be placed but is associated with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Vena Cava
The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vein that receives venous return from the upper half of the body, above the diaphragm. Venous return from the lower half, below the diaphragm, flows through the inferior vena cava. The SVC is located in the anterior right superior mediastinum. It is the typical site of central venous access via a central venous catheter or a peripherally inserted central catheter. Mentions of "the cava" without further specification usually refer to the SVC. Structure The superior vena cava is formed by the left and right brachiocephalic veins, which receive blood from the upper limbs, head and neck, behind the lower border of the first right costal cartilage. It passes vertically downwards behind first intercostal space and receives azygos vein just before it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Jugular Vein
The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the posterior compartment of the jugular foramen, at the base of the skull. It is somewhat dilated at its origin, which is called the ''superior bulb''. This vein also has a common trunk into which drains the anterior branch of the retromandibular vein, the facial vein, and the lingual vein. It runs down the side of the neck in a vertical direction, being at one end lateral to the internal carotid artery, and then lateral to the common carotid artery, and at the root of the neck, it unites with the subclavian vein to form the brachiocephalic vein (innominate vein); a little above its termination is a second dilation, the ''inferior bulb''. Above, it lies upon the rectus capitis lateralis, behind the internal carotid artery and the nerves pas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vein
Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. In contrast to veins, arteries carry blood away from the heart. Veins are less muscular than arteries and are often closer to the skin. There are valves (called ''pocket valves'') in most veins to prevent backflow. Structure Veins are present throughout the body as tubes that carry blood back to the heart. Veins are classified in a number of ways, including superficial vs. deep, pulmonary vs. systemic, and large vs. small. * Superficial veins are those closer to the surface of the body, and have no corresponding arteries. * Deep veins are deeper in the body and have corresponding arteries. * Perforator veins drain from the superficial to the deep veins. These are usually referred to in the lower limbs and feet. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
