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Congenital Portosystemic Shunt
A portosystemic shunt or portasystemic shunt (medical subject heading term; PSS), also known as a liver shunt, is a bypass of the liver by the body's circulatory system. It can be either a congenital (present at birth) or acquired condition and occurs in humans as well as in other species of animals. Congenital PSS are extremely rare in humans but are relatively common in dogs. Improvements in imaging and awareness have contributed to an increase in cases Thus a large part of medical and scientific literature on the subject is grounded in veterinary medicine. Background Blood leaving the digestive tract is rich in nutrients, as well as in toxins, which under normal conditions undergo processing and detoxification in the liver. The liver's position downstream to the intestines in the body's circulatory system - the hepatic portal vein conveys blood from the intestines to the liver - allows it to filter this nutrient rich blood before it passes to the rest of the body. The presenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liver
The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of various proteins and various other Biochemistry, biochemicals necessary for digestion and growth. In humans, it is located in the quadrants and regions of abdomen, right upper quadrant of the abdomen, below the thoracic diaphragm, diaphragm and mostly shielded by the lower right rib cage. Its other metabolic roles include carbohydrate metabolism, the production of a number of hormones, conversion and storage of nutrients such as glucose and glycogen, and the decomposition of red blood cells. Anatomical and medical terminology often use the prefix List of medical roots, suffixes and prefixes#H, ''hepat-'' from ἡπατο-, from the Greek language, Greek word for liver, such as hepatology, and hepatitis The liver is also an accessory digestive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatic Veins
In human anatomy, the hepatic veins are the veins that drain venous blood from the liver into the inferior vena cava (as opposed to the hepatic portal vein which conveys blood from the gastrointestinal organs to the liver). There are usually three large upper hepatic veins draining from the left, middle, and right parts of the liver, as well as a number (6-20) of lower hepatic veins. All hepatic veins are valveless. Structure All the hepatic veins drain into the inferior vena cava. The hepatic veins are divided into an upper and a lower group. Upper group The upper group consists of three hepatic veins - the right, middle, and left hepatic veins - draining the central veins from the right, middle, and left regions of the liver and are larger than the lower group of veins. The veins of the upper group drain into the suprahepatic part of the inferior vena cava (i.e. part superior to the liver). Right hepatic vein The right hepatic vein is the longest and largest of all the h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatic Encephalopathy
Hepatic encephalopathy (HE) is an altered level of consciousness as a result of liver failure. Its onset may be gradual or sudden. Other symptoms may include movement problems, changes in mood, or changes in personality. In the advanced stages, it can result in a coma. Hepatic encephalopathy can occur in those with acute or chronic liver disease. Episodes can be triggered by infections, gastrointestinal bleeding, constipation, electrolyte problems, or certain medications. The underlying mechanism is believed to involve the buildup of ammonia in the blood, a substance that is normally removed by the liver. The diagnosis is typically based on symptoms after ruling out other potential causes. It may be supported by blood ammonia levels, an electroencephalogram, or computer tomography (CT scan) of the brain. Hepatic encephalopathy is possibly reversible with treatment. This typically involves supportive care and addressing the triggers of the event. Lactulose is fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encephalopathy
Encephalopathy (; ) means any disorder or disease of the brain, especially chronic degenerative conditions. In modern usage, encephalopathy does not refer to a single disease, but rather to a syndrome of overall brain dysfunction; this syndrome has many possible organic and inorganic causes. Types There are many types of encephalopathy. Some examples include: * Mitochondrial encephalopathy: Metabolic disorder caused by dysfunction of mitochondrial DNA. Can affect many body systems, particularly the brain and nervous system. * Acute necrotizing encephalopathy, rare disease that occurs following a viral infection. * Glycine encephalopathy: A genetic metabolic disorder involving excess production of glycine. * Hepatic encephalopathy: Arising from advanced cirrhosis of the liver. * Hypoxic ischemic encephalopathy: Permanent or transitory encephalopathy arising from severely reduced oxygen delivery to the brain. * Static encephalopathy: Unchanging, or permanent, brain damage, u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Hypertension
Pulmonary hypertension (PH or PHTN) is a condition of increased blood pressure in the pulmonary artery, arteries of the lungs. Symptoms include dypsnea, shortness of breath, Syncope (medicine), fainting, tiredness, chest pain, pedal edema, swelling of the legs, and a fast heartbeat. The condition may make it difficult to exercise. Onset is typically gradual. According to the definition at the 6th World Symposium of Pulmonary Hypertension in 2018, a patient is deemed to have pulmonary hypertension if the pulmonary mean arterial pressure is greater than 20mmHg at rest, revised down from a purely arbitrary 25mmHg, and pulmonary vascular resistance (PVR) greater than 3 Wood units. The cause is often unknown. Risk factors include a family history, prior pulmonary embolism (blood clots in the lungs), HIV/AIDS, sickle cell disease, cocaine use, chronic obstructive pulmonary disease, sleep apnea, living at high altitudes, and problems with the mitral valve. The underlying mechanism typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatopulmonary Syndrome
In medicine, hepatopulmonary syndrome is a syndrome of shortness of breath and hypoxemia (low oxygen levels in the blood of the arteries) caused by vasodilation (broadening of the blood vessels) in the lungs of patients with liver disease. Dyspnea and hypoxemia are worse in the upright position (which is called platypnea and orthodeoxia, respectively). Pathophysiology The hepatopulmonary syndrome results from the formation of microscopic intrapulmonary arteriovenous dilatations in patients with both chronic, and far less commonly acute liver failure. The mechanism is unknown but is thought to be due to increased liver production or decreased liver clearance of vasodilators, possibly involving nitric oxide. The dilation of these blood vessels causes overperfusion relative to ventilation, leading to ventilation-perfusion mismatch and hypoxemia. There is an increased gradient between the partial pressure of oxygen in the alveoli of the lung and adjacent arteries (alveolar-arterial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholestasis
Cholestasis is a condition where the flow of bile from the liver to the duodenum is impaired. The two basic distinctions are: * obstructive type of cholestasis, where there is a mechanical blockage in the duct system that can occur from a gallstone or malignancy, and * metabolic type of cholestasis, in which there are disturbances in bile formation that can occur because of genetic defects or acquired as a side effect of many medications. Classification is further divided into acute or chronic and extrahepatic or intrahepatic. Signs and symptoms The signs and symptoms of cholestasis vary according to the cause. In case of sudden onset, the disease is likely to be acute, while the gradual appearance of symptoms suggests chronic pathology. In many cases, patients may experience pain in the abdominal area. Localization of pain to the upper right quadrant can be indicative of cholecystitis or choledocholithiasis, which can progress to cholestasis. Pruritus or itching is often pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Pass Effect
The first pass effect (also known as first-pass metabolism or presystemic metabolism) is a phenomenon of drug metabolism at a specific location in the body which leads to a reduction in the concentration of the active drug before it reaches the site of action or systemic circulation. The effect is most associated with orally administered medications, but some drugs still undergo first-pass metabolism even when delivered via an alternate route (e.g., IV, IM, etc.). During this metabolism, drug is lost during the process of absorption which is generally related to the liver and gut wall. The liver is the major site of first pass effect; however, it can also occur in the lungs, vasculature or other metabolically active tissues in the body. Notable drugs that experience a significant first pass effect are buprenorphine, chlorpromazine, cimetidine, diazepam, ethanol (drinking alcohol), imipramine, insulin, lidocaine, midazolam, morphine, pethidine, propranolol, and tetrahydroca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart
The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrients to the tissue, 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 thorax, chest, called the mediastinum. In humans, the heart is divided into four chambers: upper left and right Atrium (heart), atria and lower left and right Ventricle (heart), ventricles. Commonly, the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. In a healthy heart, blood flows one way through the heart due to heart valves, which prevent cardiac regurgitation, backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a sma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venae Cavae
In anatomy, the ''venae cavae'' (; ''vena cava'' ; ) are two large veins (great vessels) that return deoxygenated blood from the body into the heart. In humans they are the superior vena cava and the inferior vena cava, and both empty into the right atrium. They are located slightly off-center, toward the right side of the body. The right atrium receives deoxygenated blood through coronary sinus and two large veins called venae cavae. The inferior vena cava (or caudal vena cava in some animals) travels up alongside the abdominal aorta with blood from the lower part of the body. It is the largest vein in the human body. MadSci Network: Anatomy. Retrieved 19 September 2013. The superior vena cava (or cranial vena cava in animals) is above the heart, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capillary
A capillary is a small blood vessel, from 5 to 10 micrometres in diameter, and is part of the microcirculation system. Capillaries are microvessels and the smallest blood vessels in the body. They are composed of only the tunica intima (the innermost layer of an artery or vein), consisting of a thin wall of simple squamous endothelial cells. They are the site of the exchange of many substances from the surrounding interstitial fluid, and they convey blood from the smallest branches of the arteries (arterioles) to those of the veins (venules). Other substances which cross capillaries include water, oxygen, carbon dioxide, urea, glucose, uric acid, lactic acid and creatinine. Lymph capillaries connect with larger lymph vessels to drain lymphatic fluid collected in microcirculation. Etymology ''Capillary'' comes from the Latin word , meaning "of or resembling hair", with use in English beginning in the mid-17th century. The meaning stems from the tiny, hairlike diameter of a capi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intestines
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. The GI tract contains all the major organs of the digestive system, in humans and other animals, including the esophagus, stomach, and intestines. Food taken in through the mouth is digested to extract nutrients and absorb energy, and the waste expelled at the anus as feces. ''Gastrointestinal'' is an adjective meaning of or pertaining to the stomach and intestines. Most animals have a "through-gut" or complete digestive tract. Exceptions are more primitive ones: sponges have small pores ( ostia) throughout their body for digestion and a larger dorsal pore ( osculum) for excretion, comb jellies have both a ventral mouth and dorsal anal pores, while cnidarians and acoels have a single pore for both digestion and excretion. The human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
