Dementia Glossary of Medical Terms

These are medical definitions of medical terms from the MedTerms.com medical dictionary that appear in the Dementia article.

Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer ).
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Acetylcholine: A key chemical in neurons (nerve cells) that acts as a neurotransmitter and carries information across the synaptic cleft , the space between two nerve cells. Abbreviated ACh.
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Aging: The process of becoming older, a process that is genetically determined and environmentally modulated.
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Alcoholism: Physical dependence on alcohol to the extent that stopping alcohol use will bring on withdrawal symptoms. In popular and therapeutic parlance, the term may also be used to refer to ingrained drinking habits that cause health or social problems. Treatment requires first ending the physical dependence, then making lifestyle changes that help the individual avoid relapse . In some cases, medication or hospitalization are needed. Alcohol dependence can have many serious effects on the brain , liver , and other organs of the body.
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Alzheimer disease: See: Alzheimer's disease .
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Alzheimer's disease: A progressive neurologic disease of the brain that leads to the irreversible loss of neurons and dementia . The clinical hallmarks of Alzheimer's disease are progressive impairment in memory, judgment, decision making, orientation to physical surroundings, and language. A working diagnosis of Alzheimer disease is usually made on the basis of the neurologic examination. A definitive diagnosis can be made only at autopsy. On a cellular level, Alzheimer's disease is characterized by unusual helical protein filaments in nerve cells (neurons) of the brain. These odd twisted filaments are called neurofibrillary tangles. On a functional level, there is degeneration of the cortical regions, especially the frontal and temporal lobes, of the brain.
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Anemia: The condition of having less than the normal number of red blood cells or less than the normal quantity of hemoglobin in the blood. The oxygen-carrying capacity of the blood is, therefore, decreased.
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Anticholinergic: The action of certain medications that inhibit the transmission of parasympathetic nerve impulses and thereby reduce spasms of smooth muscle (such as that, for example, in the bladder).
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Anticonvulsant: A medication used to control (prevent) seizures (convulsions) or stop an ongoing series of seizures. There are a large number of anticonvulsant drugs today including, but not limited to: phenobarbital, phenytoin (Dilantin), carbamazepine , ethosuximide (Zarontin), clonazepam (Klonopin), diazepam (Valium), lorazepam (Ativan), and midazolam (Versed). Anticonvulsant drugs taken during pregnancy put the baby at risk of major birth defects -- growth retardation, microcephaly (a small head) and deformities of the face and fingers -- a condition known as anticonvulsant embryopathy.
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Antidepressants : Anything, and especially a drug, used to prevent or treat depression .
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Antipsychotic: A medication (or another measure) that is believed to be effective in the treatment of psychosis . For example, aripiprazole (Abilify) is an antipsychotic medication used to treat schizophrenia .
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Anxiety: A feeling of apprehension and fear characterized by physical symptoms such as palpitations , sweating, and feelings of stress . Anxiety disorders are serious medical illnesses that affect approximately 19 million American adults. These disorders fill people's lives with overwhelming anxiety and fear. Unlike the relatively mild, brief anxiety caused by a stressful event such as a business presentation or a first date, anxiety disorders are chronic, relentless, and can grow progressively worse if not treated.
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Aspiration: Removal of a sample of fluid and cells through a needle. Aspiration also refers to the accidental sucking in of food particles or fluids into the lungs.
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Assisted living: A type of long-term care facility for elderly or disabled people who are able to get around on their own but who may need help with some activities of daily living, or simply prefer the convenience of having their meals in a central cafeteria and having nursing staff on call.
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Atherosclerosis: A process of progressive thickening and hardening of the walls of medium-sized and large arteries as a result of fat deposits on their inner lining.
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Atrophy: Wasting away or diminution. Muscle atrophy is wasting of muscle, decrease in muscle mass.
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Benign: Not cancer. Not malignant . A benign tumor does not invade surrounding tissue or spread to other parts of the body. A benign tumor may grow but it stays put (in the same place).
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Binswanger disease: A form of dementia with blood vessel abnormalities in the deep white-matter of the brain causing loss of memory, decreasing cognition, and mood changes. Patients usually show signs of abnormal blood pressure (too high or too low), stroke , blood abnormalities, disease of the large blood vessels in the neck, and disease of the heart valves. Other prominent features of the disease include urinary incontinence , difficulty walking, tremors similar to Parkinson's disease, and depression . Seizures may also occur.
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Bladder: Any pouch or other flexible enclosure that can hold liquids or gases but usually refers to the hollow organ in the lower abdomen that stores urine -- the urinary bladder. The kidneys filter waste from the blood and produce urine, which enters the bladder through two tubes called ureters. Urine leaves the bladder through another tube, the urethra . In women, the urethra is a short tube that opens just in front of the vagina . In men, it is longer, passing through the prostate gland and then the penis . Infection of the bladder is called cystitis .
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Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle . It's measurement is recorded by two numbers. The first ( systolic pressure) is measured after the heart contracts and is highest. The second ( diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called " hypertension ".
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Brain: That part of the central nervous system that is located within the cranium ( skull ). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."
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Brain tumor : A benign or malignant growth in the brain. Primary brain tumors arise in brain tissue. Secondary brain tumors are cancers that have spread to the brain tissue (metastasized) from elsewhere in the body. Brain tumors can and do occur at any age.
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CBC: A commonly used abbreviation in medicine that stands for complete blood count , a set values of the cellular (formed elements) of blood. These measurements are generally determined by specially designed machines that analyze the different components of blood in less than a minute.
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Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane .
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Cerebral: Pertaining to the brain, the cerebrum or the intellect.
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Cerebral cortex: A thin mantle of gray matter about the size of a formal dinner napkin covering the surface of each cerebral hemisphere. The cerebral cortex is crumpled and folded, forming numerous convolutions ( gyri ) and crevices ( sulci ). It is made up of six layers of nerve cells and the nerve pathways that connect them. The cerebral cortex is responsible for the processes of thought, perception and memory and serves as the seat of advanced motor function, social abilities, language, and problem solving.
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Cerebrospinal fluid: CSF. A watery fluid, continuously produced and absorbed, which flows in the ventricles (cavities) within the brain and around the surface of the brain and spinal cord.
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Cholesterol: The most common type of steroid in the body, cholesterol has gotten something of a bad name. However, cholesterol is a critically important molecule.
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Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time.
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Circulation: The movement of fluid in a regular or circuitous course. Although the noun "circulation" does not necessarily refer to the circulation of the blood, for all practical purposes today it does. Heart failure is an example of a problem with the circulation.
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Cocaine: The most potent stimulant of natural origin, a bitter addictive anesthetic (pain blocker) which is extracted from the leaves of the coca scrub (Erythroxylon coca) indigenous to the Andean highlands of South America.
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Cognition: The process of knowing and, more precisely, the process of being aware, knowing, thinking, learning and judging. The study of cognition touches on the fields of psychology, linguistics, computer science, neuroscience, mathematics, ethology and philosophy.
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Cognitive: Pertaining to cognition , the process of knowing and, more precisely, the process of being aware, knowing, thinking, learning and judging. The study of cognition touches on the fields of psychology , linguistics, computer science, neuroscience , mathematics, ethology and philosophy.
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Coma: A state of deep unarousable unconsciousness.
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Congestive heart failure : Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling ( edema ), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart.
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Constipation: Infrequent (and frequently incomplete) bowel movements. The opposite of diarrhea , constipation is commonly caused by irritable bowel syndrome, diverticulosis , and medications (constipation can paradoxically be caused by overuse of laxatives). Colon cancer can narrow the colon and thereby cause constipation. The large bowel (colon) can be visualized by barium enema x-rays, sigmoidoscopy, and colonoscopy. Barring a condition such as cancer, high-fiber diets can frequently relieve the constipation.
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Cortex: The outer portion of an organ.
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Cortical: Having to do with the cortex, the outer portion of an organ.
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CT scan: Computerized tomography scan. Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them into pictures on a screen. CT stands for computerized tomography.
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Cure: 1. To heal, to make well, to restore to good health. Cures are easy to claim and, all too often, difficult to confirm.
2. A time without recurrence of a disease so that the risk of recurrence is small, as in the 5-year cure rate for malignant melanoma .
3. Particularly in the past, a course of treatment. For example, take a cure at a spa.
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Dehydration : Excessive loss of body water. Diseases of the gastrointestinal tract that cause vomiting or diarrhea may, for example, lead to dehydration. There are a number of other causes of dehydration including heat exposure, prolonged vigorous exercise (e.g., in a marathon), kidney disease, and medications (diuretics).
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Delirium: A sudden state of severe confusion and rapid changes in brain function, sometimes associated with hallucinations and hyperactivity , in which the patient is inaccessible to normal contact. Symptoms may include inability to concentrate and disorganized thinking evidenced by rambling, irrelevant, or incoherent speech. There may be a reduced level of consciousness, sensory misperceptions and illusions, disturbances of sleep, drowsiness, disorientation to time, place, or person, and problems with memory.
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Dementia : Significant loss of intellectual abilities such as memory capacity, severe enough to interfere with social or occupational functioning.
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Depression : An illness that involves the body, mood, and thoughts, that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely "pull themselves together" and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression.
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Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus . Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria).
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Diagnosis: 1 The nature of a disease ; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies . 3 The identification of any problem. The diagnosis was a plugged IV.
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Dry mouth: The condition of not having enough saliva to keep the mouth wet. This is due to inadequate function of the salivary glands. Everyone has dry mouth once in a while when they are nervous, upset or under stress. But if someone has a dry mouth most all of the time, it can be uncomfortable and lead to serious health problems.
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Dysfunction: Difficult function or abnormal function.
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EEG: Electroencephalogram, e technique for studying the electrical current within the brain. Electrodes are attached to the scalp. Wires attach these electrodes to a machine which records the electrical impulses. The results are either printed out or displayed on a computer screen. Electroencephalogram is abbreviated EEG.
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Emphysema: 1) A lung condition featuring an abnormal accumulation of air in the lung's many tiny air sacs, a tissue called alveoli. As air continues to collect in these sacs, they become enlarged, and may break, or be damaged and form scar tissue. Emphysema is strongly associated with smoking cigarettes, a practice that causes lung irritation. It can also be associated with or worsened by repeated infection of the lungs, such as is seen in chronic bronchitis. The best response to the early warning signs of emphysema is prevention: stop smoking and get immediate treatment for incipient lung infections. Curing established emphysema is not yet possible. Because patients don't have an adequate amount of space in the lungs to breathe, they gasp for breath, and may not be able to obtain enough oxygen. Those with severe emphysema usually end up using an oxygen machine to breathe. In some cases, medication may be helpful to ease symptoms or to treat infection in already-damaged lungs.
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Encephalitis: Inflammation of the brain. Encephalitis occurs, for example, in 1 in 1,000 cases of measles . It may start (up to 3 weeks) after onset of the measles rash and present with high fever , convulsions, and coma. It usually runs a blessedly short course with full recovery within a week. Or it may eventuate in central nervous system impairment or death.
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Enzyme: A protein (or protein-based molecule) that speeds up a chemical reaction in a living organism. An enzyme acts as catalyst for specific chemical reactions , converting a specific set of reactants (called substrates) into specific products. Without enzymes, life as we know it would not exist.
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Fats: Plural of the word "fat". See the definition of fat .
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FDA: The Food and Drug Administration, an agency within the U.S. Public Health Service, which is a part of the Department of Health and Human Services.
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Folic acid: One of the B vitamins that is a key factor in the synthesis (the making) of nucleic acid (DNA and RNA).
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Food and Drug Administration: The FDA, an agency within the U.S. Public Health Service, which is a part of the Department of Health and Human Services.
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Gait: A manner of walking. Observation of the gait can provide clues to a number of diagnoses including Parkinson disease, cerebral palsy , congenital dislocation of the hip, and stroke .
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Gland: 1. A group of cells that secrete a substance for use in the body. For example, the thyroid gland. 2. A group of cells that removes materials from the circulation. For example, a lymph gland.
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Head injury: Damage to any of the structures of the head as a result of trauma. While the term "head injury" is most often used to refer to an injury to the brain, head injuries may also involve the bones, muscles, blood vessels, skin, and other organs of the face or head. A head injury does not always mean that there is an associated brain injury. Most head injuries are caused by blows to the head from numerous causes including motor vehicle accidents and falls. Head injuries are one of the most common causes of death and disability in the United States.
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Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.
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Heart disease: Any disorder that affects the heart. Sometimes the term "heart disease" is used narrowly and incorrectly as a synonym for coronary artery disease . Heart disease is synonymous with cardiac disease but not with cardiovascular disease which is any disease of the heart or blood vessels. Among the many types of heart disease, see, for example: Angina ; Arrhythmia ; Congenital heart disease ; Coronary artery disease (CAD); Dilated cardiomyopathy ; Heart attack (myocardial infarction); Heart failure ; Hypertrophic cardiomyopathy ; Mitral regurgitation ; Mitral valve prolapse ; and Pulmonary stenosis .
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Heart failure : Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling ( edema ), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart.
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Heroin: Semisynthetic drug derived from morphine. Discovered in 1874, it was introduced commercially in 1898 by the Bayer company in Germany. The name heroin was coined from the German heroisch meaning heroic, strong. Heroin is stronger (more potent) than morphine.
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High blood pressure : Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
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HIV: Acronym for the Human Immunodeficiency Virus , the cause of AIDS (acquired immunodeficiency syndrome). HIV has also been called the human lymphotropic virus type III, the lymphadenopathy-associated virus and the lymphadenopathy virus . No matter what name is applied, it is a retrovirus. (A retrovirus has an RNA genome and a reverse transcriptase enzyme. Using the reverse transcriptase , the virus uses its RNA as a template for making complementary DNA which can integrate into the DNA of the host organism).
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Hormone: A chemical substance produced in the body that controls and regulates the activity of certain cells or organs.
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Huntington disease : An hereditary disorder with mental and physical deterioration leading to death. Although characterized as an "adult-onset" disease, it can affect children as well.
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Hydrocephalus: Hydrocephalus is an abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain. The fluid is often under increased pressure and can compress and damage the brain.
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Hypothalamus: The area of the brain that controls body temperature, hunger, and thirst.
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Hypoxia: A subnormal concentration of oxygen . By contrast with normoxia (normal oxygen) and anoxia (the absence or near absence of oxygen). From hyp- (below) + -ox- (oxygen) + -ia.
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Hypoxic: Pertaining to hypoxia , a subnormal concentration of oxygen .
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Incontinence: Inability to control excretions. Urinary incontinence is inability to keep urine in the bladder. Fecal incontinence is inability to retain feces in the rectum.
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Incontinent: Unable to control excretions, to hold urine in the bladder or keep feces in the rectum . This is the usual medical meaning of the word incontinent. Incontinent can also refer to a lack of self-restraint in the sexual arena or failure to refrain from sexual intercourse.
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Infarction: The formation of an infarct, an area of tissue death due to a local lack of oxygen.
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Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person.
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Inflammation: A basic way in which the body reacts to infection , irritation or other injury, the key feature being redness, warmth, swelling and pain . Inflammation is now recognized as a type of nonspecific immune response .
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Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury . The injury may be accidental or deliberate, as with a needlestick injury . The term "injury" may be synonymous (depending on the context) with a wound or with trauma .
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Kidney: One of a pair of organs located in the right and left side of the abdomen which clear "poisons" from the blood, regulate acid concentration and maintain water balance in the body by excreting urine. The kidneys are part of the urinary tract. The urine then passes through connecting tubes called "ureters" into the bladder. The bladder stores the urine until it is released during urination.


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Limb: The arm or leg.
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Liver: An organ in the upper abdomen that aids in digestion and removes waste products and worn-out cells from the blood. The liver is the largest solid organ in the body. The liver weighs about three and a half pounds (1.6 kilograms). It measures about 8 inches (20 cm) horizontally (across) and 6.5 inches (17 cm) vertically (down) and is 4.5 inches (12 cm) thick.


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Liver disease: Liver disease refers to any disorder of the liver. The liver is a large organ in the upper right abdomen that aids in digestion and removes waste products from the blood.
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Long-term memory: A system for permanently storing, managing, and retrieving information for later use. Items of information stored as long-term memory may be available for a lifetime.
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Lumbar: Referring to the 5 lumbar vertebrae which are situated below the thoracic vertebrae and above the sacral vertebrae in the spinal column. The 5 lumbar vertebrae are represented by the symbols L1 through L5. There are correspondingly 5 lumbar nerves.
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Lumbar puncture: A lumbar puncture or "LP" is a procedure whereby spinal fluid is removed from the spinal canal for the purpose of diagnostic testing. It is particularly helpful in the diagnosis of inflammatory diseases of the central nervous system, especially infections, such as meningitis. It can also provide clues to the diagnosis of stroke , spinal cord tumor and cancer in the central nervous system.
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Lungs: The lungs are a pair of breathing organs located with the chest which remove carbon dioxide from and bring oxygen to the blood. There is a right and left lung.
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Malnutrition: A term used to refer to any condition in which the body does not receive enough nutrients for proper function. Malnutrition may range from mild to severe and life-threatening. It can be a result of starvation, in which a person has an inadequate intake of calories, or it may be related to a deficiency of one particular nutrient (for example, vitamin C deficiency). Malnutrition can also occur because a person can not properly digest or absorb nutrients from the food they consume, as may occur with certain medical conditions. Malnutrition remains a significant global problem, especially in developing countries.
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Memory: 1. The ability to recover information about past events or knowledge. 2. The process of recovering information about past events or knowledge. 3. Cognitive reconstruction. The brain engages in a remarkable reshuffling process in an attempt to extract what is general and what is particular about each passing moment.
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Metabolic: Relating to metabolism, the whole range of biochemical processes that occur within us (or any living organism). Metabolism consists of anabolism (the buildup of substances) and catabolism (the breakdown of substances).
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Microscopic: So small it cannot be seen without the aid of microscope. As opposed to macroscopic (large enough to be seen with naked eye). A tiny tumor is microscopic while a big tumor is macroscopic.
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Motor: In medicine, having to do with the movement of a part of the body. Something that produces motion or refers to motion. For example, a motor neuron is a nerve cell that conveys an impulse to a muscle causing it to contract. The term "motor" today is also applied to a nerve that signals a gland to secrete. Motor is as opposed to sensory.
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Mouth: 1. The upper opening of the digestive tract, beginning with the lips and containing the teeth, gums, and tongue. Foodstuffs are broken down mechanically in the mouth by chewing and saliva is added as a lubricant. Saliva contains amylase, an enzyme that digests starch. 2. Any opening or aperture in the body. The mouth in both senses of the word is also called the os, the Latin word for an opening, or mouth. The o in os is pronounced as in hope. The genitive form of os is oris from which comes the word oral.
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MRI: Abbreviation and nickname for magnetic resonance imaging . For more information, see: Magnetic Resonance Imaging ; Paul C. Lauterbur ; Peter Mansfield .
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Mucus: A thick slippery fluid produced by the membranes lining certain organs such as the nose, mouth, throat, and vagina. Mucus is the Latin word for "a semifluid, slimy discharge from the nose." Note that mucus is a noun while the adjective is mucous.
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Multi-infarct dementia: Dementia brought on by a series of strokes. See Vascular dementia .
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Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."
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Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. See: Nervous system .
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Neurological: Having to do with the nerves or the nervous system.
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Neurology: The medical specialty concerned with the diagnosis and treatment of disorders of the nervous system -- the brain, the spinal cord, and the nerves.
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Neurotransmitter: A chemical that is released from a nerve cell which thereby transmits an impulse from a nerve cell to another nerve, muscle, organ, or other tissue. A neurotransmitter is a messenger of neurologic information from one cell to another.
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Normal pressure hydrocephalus: A specific form of hydrocephalus in which the central cavities of the inner brain (the ventricles) enlarge at the expense of the substance of the brain, while the pressure of the CSF remains within normal range. Normal pressure hydrocephalus (NPH) is due usually to a gradual blockage of the drainage pathways for cerebrospinal fluid (CSF) in the brain. NPH can occur as a complication of brain infection or hemorrhage. In some patients no predisposing cause can be identified.
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Nursing: 1) Profession concerned with the provision of services essential to the maintenance and restoration of health by attending the needs of sick persons. 2) Feeding a infant at the breast .
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Nursing home: A residential facility for persons with chronic illness or disability, particularly older people who have mobility and eating problems. Also called a convalescent home, long-term care facility.
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Organic: 1. A chemical compound that contains carbon.
2. Related to an organ.
3. Grown or prepared without the use of chemicals or pesticides, as in organic food.
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Organic brain syndrome: Psychiatric or neurological symptoms, including problems with attention, concentration, and memory, confusion, anxiety, and depression, arising from damage to or disease in the brain. Also called organic mental disorder. See also: Neurobiological disorder .
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Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life.
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Oxygenation: The addition of oxygen to any system, including the human body. Oxygenation may also refer to the process of treating a patient with oxygen, or of combining a medication or other substance with oxygen.
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PA-C: Physician Assistant - Certified.
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Pancreas: A fish-shaped spongy grayish-pink organ about 6 inches (15 cm) long that stretches across the back of the abdomen, behind the stomach. The head of the pancreas is on the right side of the abdomen and is connected to the duodenum (the first section of the small intestine). The narrow end of the pancreas, called the tail, extends to the left side of the body.


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Parkinson disease : A slowly progressive neurologic disease characterized by a fixed inexpressive face, a tremor at rest, slowing of voluntary movements, a gait with short accelerating steps, peculiar posture and muscle weakness, caused by degeneration of an area of the brain called the basal ganglia , and by low production of the neurotransmitter dopamine . Most patients are over 50, but at least 10 percent are under 40. Also known as paralysis agitans and shaking palsy.
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Parkinson's disease: See: Parkinson disease .
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Pharmacy: A location where prescription drugs are sold. A pharmacy is, by law, constantly supervised by a licensed pharmacist.
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Physical therapy: A branch of rehabilitative health that uses specially designed exercises and equipment to help patients regain or improve their physical abilities. Physical therapists work with many types of patients, from infants born with musculoskeletal birth defects, to adults suffering from sciatica or the after- effects of injury, to elderly post-stroke patients.
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Pick disease : A form of dementia characterized by a slowly progressive deterioration of social skills and changes in personality leading to impairment of intellect, memory, and language.
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Pituitary: 1. As an adjective, pertaining to the pituitary gland or its hormonal secretions. 2. As a noun, the pituitary gland itself.
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Pituitary gland: The main endocrine gland. It is a small structure in the head. It is called the master gland because it produces hormones that control other glands and many body functions including growth. The pituitary consists of the anterior and posterior pituitary.
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Pneumonia: Inflammation of one or both lungs with consolidation. Pneumonia is frequently but not always due to infection. The infection may be bacterial, viral, fungal or parasitic. Symptoms may include fever, chills, cough with sputum production, chest pain, and shortness of breath.
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Prescription: A physician's order for the preparation and administration of a drug or device for a patient. A prescription has several parts. They include the superscription or heading with the symbol "R" or "Rx", which stands for the word recipe (meaning, in Latin, to take); the inscription, which contains the names and quantities of the ingredients; the subscription or directions for compounding the drug; and the signature which is often preceded by the sign "s" standing for signa (Latin for mark), giving the directions to be marked on the container.
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Prostate: A gland within the male reproductive system that is located just below the bladder. Chestnut shaped, the prostate surrounds the beginning of the urethra, the canal that empties the bladder.
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Prostate enlargement: Most prostatic enlargement is due to benign prostatic hyperplasia (BPH), a problem that bothers men increasingly with advancing age. The process of BPH generally begins in a man's 30s, evolves very slowly and usually causes symptoms only after he has passed the half-century mark.
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Protein: A large molecule composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein.
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Psychiatry: The medical specialty concerned with the prevention, diagnosis , and treatment of mental illness.
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Psychosis: In the general sense, a mental illness that markedly interferes with a person's capacity to meet life's everyday demands. In a specific sense, it refers to a thought disorder in which reality testing is grossly impaired.
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Quality of life: An important consideration in medical care, quality of life refers to the patient's ability to enjoy normal life activities. Some medical treatments can seriously impair quality of life without providing appreciable benefit, while others greatly enhance quality of life.
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Re-uptake: See: Reuptake .
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Referral: The recommendation of a medical or paramedical professional. If you get a referral to ophthalmology, for example, you are being sent to the eye doctor. In HMOs and other managed care schemes, a referral is usually necessary to see any practitioner or specialist other than your primary care physician (PCP), if you want the service to be covered. The referral is obtained from your PCP, who may require a telephone or office consultation first.
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Regimen: With the accent on the first syllable (reg as in Reggie Jackson), a regimen is a plan, a regulated course such as a diet, exercise or treatment, designed to give a good result. A low-salt diet is a regimen.
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Rehydration: The process of restoring lost water to the body tissues and fluids. Prompt rehydration is imperative whenever dehydration occurs, from diarrhea , exposure, lack of drinking water, or medication use. Rehydration can be by the oral route or by the intravenous administration of fluids.
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Rule out: A term much used in medicine, meaning to eliminate or exclude something from consideration. The ACB (albumin cobalt binding) test helps rule out a heart attack in the differential diagnosis of severe chest pain.
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Safe sex: 1. A sexual practice designed to reduce the risk of catching sexually transmitted infections (STIs). 2. A sexual practice that does not involve the exchange of bodily fluids, including blood, sperm , vaginal secretions, and saliva, to avoid AIDS and other sexually transmitted infections. 3. Sex without penetration, or sex using condoms and Nonoxynol-9 spermacide, and/or vaginal dams, with consistency.
In reality, no matter which meaning one ascribes to safe sex, "safer sex" is a more apt term.
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Saliva: a watery secretion in the mouth produced by the salivary glands that aids in the digestion of food. Saliva also serves to moisten and cleanse the mouth, including the tongue and teeth, and contains substances that can play a role in the prevention of infection . Saliva aids digestion by moistening food and contains enzymes that begin the digestion process. Also known as spit.
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Scan: As a noun, the data or image obtained from the examination of organs or regions of the body by gathering information with a sensing device.
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Seat belt: A belt used to hold an individual in their seat.
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Senile: 1. Pertaining to old age. 2. Pertaining to the physical decline associated with old age. 3. Pertaining to the mental decline once associated with old age but now known to be due to dementia , such as Alzheimer's disease or cerebral atherosclerosis . "The road to senility is paved with plaques." (Paul F. Wehrle, MD [1921-2004] pediatrician and vaccine researcher)
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Senility: 1. Originally, old age. 2. The physical decline associated with old age. 3. The mental decline once associated with old age but now known to be due to dementia , as for instance Alzheimer's disease and atherosclerosis. "The road to senility is paved with plaques." (Paul F. Wehrle, MD [1921-2004] pediatrician and vaccine researcher who helped eradicate smallpox)
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Serotonin: A hormone , also called 5-hydroxytryptamine , in the pineal gland , blood platelets, the digestive tract, and the brain. Serotonin acts both as a chemical messenger that transmits nerve signals between nerve cells and that causes blood vessels to narrow.
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Short-term memory: A system for temporarily storing and managing information required to carry out complex cognitive tasks such as learning, reasoning, and comprehension. Short-term memory is involved in the selection, initiation, and termination of information-processing functions such as encoding, storing, and retrieving data.
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Shunt: 1) To move a body fluid, such as cerebrospinal fluid, from one place to another. 2) A catheter (tube) that carries cerebrospinal fluid from a ventricle in the brain to another area of the body. A shunt may be placed to relieve pressure from hydrocephalus , for example.
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Skull: The skull is a collection of bones which encase the brain and give form to the head and face. The bones of the skull include the following: the frontal, parietal, occipital, temporal, sphenoid, ethmoid, zygomatic, maxilla, nasal, vomer, palatine, inferior concha, and mandible.
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Sleep : The body's rest cycle.
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Sleeplessness: Insomnia . See also Fatal familial insomnia .
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Soothing: Bringing comfort, solace, reassurance, peace, composure, quietude.
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SPECT: An acronym that stands for Single Photon Emission Computed Tomography, a nuclear medicine procedure in which a gamma camera rotates around the patient and takes pictures from many angles, which a computer then uses to form a tomographic (cross-sectional) image.
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Spinal tap: Also known as a lumbar puncture or "LP", a spinal tap is a procedure whereby spinal fluid is removed from the spinal canal for the purpose of diagnostic testing. It is particularly helpful in the diagnosis of inflammatory diseases of the central nervous system, especially infections, such as meningitis. It can also provide clues to the diagnosis of stroke , spinal cord tumor and cancer in the central nervous system.
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Spine: 1) The column of bone known as the vertebral column, which surrounds and protects the spinal cord. The spine can be categorized according to level of the body: i.e., cervical spine (neck), thoracic spine (upper and middle back), and lumbar spine (lower back). See also vertebral column. 2) Any short prominence of bone. The spines of the vertebrae protrude at the base of the back of the neck and in the middle of the back. These spines protect the spinal cord from injury from behind.
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Stress: Forces from the outside world impinging on the individual. Stress is a normal part of life that can help us learn and grow. Conversely, stress can cause us significant problems.
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Stroke: The sudden death of some brain cells due to a lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. A stroke is also called a cerebrovascular accident or, for short, a CVA.
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Substance: 1. Material with particular features, as a pressor substance .
2. The material that makes up an organ or structure. Also known in medicine as the substantia.
3. A psychoactive drug as, for example, in substance abuse .
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Substance abuse: The excessive use of a substance, especially alcohol or a drug. (There is no universally accepted definition of substance abuse.)
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Suicidal: Pertaining to suicide . the taking of ones own life. As in a suicidal gesture, suicidal thought, or suicidal act. An "online lifeline for suicidal undergrads" may help prevent college students from committing suicide.
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Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office.
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Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease.
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Syphilis: A sexually transmitted disease caused by Treponema pallidum, a microscopic organism called a spirochete. This worm-like, spiral-shaped organism infects people by burrowing into the moist mucous membranes of the mouth or genitals. From there, the spirochete produces a non-painful ulcer known as a chancre. There are three stages of syphilis:
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Therapy: The treatment of disease .
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Thyroid: 1. The thyroid gland . Also, pertaining to the thyroid gland. 2. A preparation of the thyroid gland used to treat hypothyroidism . 3. Shaped like a shield. (The thyroid gland was so-named by Thomas Wharton in 1656 because it was shaped like an ancient Greek shield.)
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Thyroid gland: A gland that makes and stores hormones that help regulate the heart rate, blood pressure, body temperature, and the rate at which food is converted into energy. Thyroid hormones are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions ( metabolism ) in the body. Thyroid hormones also help children grow and develop.
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Traumatic brain injury: Brain damage from trauma. The three leading causes of death from traumatic brain injury relate to firearms, motor vehicles and falls. The leading causes of death differ by age group. Motor vehicles are the leading cause among youth from birth to 19 years of age. Firearms are the leading cause of death among persons aged 20 to 74 years. Falls are the leading cause of death among persons aged 75 and older.
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Tremor: Any abnormal repetitive shaking movement of the body. Tremors have many causes and can be inherited, be related to illnesses such as thyroid disease , or caused by fever , hypothermia, drugs or fear.
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Tumor: An abnormal mass of tissue. Tumors are a classic sign of inflammation, and can be benign or malignant (cancerous). There are dozens of different types of tumors. Their names usually reflect the kind of tissue they arise in, and may also tell you something about their shape or how they grow. For example, a medulloblastoma is a tumor that arises from embryonic cells (a blastoma) in the inner part of the brain (the medulla). Diagnosis depends on the type and location of the tumor. Tumor marker tests and imaging may be used; some tumors can be seen (for example, tumors on the exterior of the skin) or felt (palpated with the hands).
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Urine: Liquid waste. The urine is a clear, transparent fluid. It normally has an amber color. The average amount of urine excreted in 24 hours is from 40 to 60 ounces (about 1,200 cubic centimeters). Chemically, the urine is mainly an aqueous (watery) solution of salt (sodium chloride) and substances called urea and uric acid. Normally, it contains about 960 parts of water to 40 parts of solid matter. Abnormally, it may contain sugar (in diabetes), albumen (a protein) (as in some forms of kidney disease), bile pigments (as in jaundice ), or abnormal quantities of one or another of its normal components.
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Vascular: Relating to the blood vessels of the body. The blood vessels of the body, as a group, are referred to as the vascular system.
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Vascular dementia: A common form of dementia in older persons that is due to cerebrovascular disease, usually with stepwise deterioration from a series of small strokes and a patchy distribution of neurologic deficits affecting some functions and not others. Risk factors include high blood pressure , an unsteady way of walking, and advanced age. Symptoms include confusion, problems with recent memory, wandering or getting lost in familiar places, loss of bladder or bowel control (incontinence), emotional problems such as laughing or crying inappropriately, difficulty following instructions, and problems handling money. The damage is typically so slight that the change is noticeable only as a series of small steps. However, over time, as more small blood vessels in the brain are blocked, there is noticeable gradual mental decline. Vascular dementia commonly begins between the ages of 60 and 75 and affects men more often than women. Also known as multi-infarct dementia. See also CADASIL .
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Ventricles: 1, The right ventricle and the left ventricle , the lower two chambers of the heart. 2. Two or more of the four connected spaces within the central portion of the brain.
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Vertebrae: The preferred plural of vertebra . (The alternate plural is vertebras.) See also: Cervical vertebrae ; Coccygeal vertebrae ; Lumbar vertebrae ; Sacral vertebrae ; and Thoracic vertebrae .
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Vitamins: The word "vitamin" was coined in 1911 by the Warsaw-born biochemist Casimir Funk (1884-1967). At the Lister Institute in London, Funk isolated a substance that prevented nerve inflammation (neuritis) in chickens raised on a diet deficient in that substance. He named the substance "vitamine" because he believed it was necessary to life and it was a chemical amine. The "e" at the end was later removed when it was recognized that vitamins need not be amines.
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Wasting: 1. Gradual loss (for example, of weight), deterioration, emaciation. As in a wasting disease. 2. Excessive depletion. As in salt wasting, the excessive loss of salt.
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