Encephalopathy Glossary of TermsThe following are health and medical definitions of terms that appear in the Encephalopathy 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). Abstinence: The voluntary self-denial of food, drink, or sex. Today, abstinence most commonly refers to denial of one's sexual activity. Acetaminophen: A pain reliever and fever reducer. Brand name: Tylenol. The exact mechanism of action of acetaminophen is not known. Acetaminophen relieves pain by elevating the pain threshold (that is, by requiring a greater amount of pain to develop before it is felt by a person). Acetaminophen reduces fever through its action on the heat-regulating center (the "thermostat") of the brain. Generic is available. 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. Acute: Of abrupt onset, in reference to a disease. Acute often also connotes an illness that is of short duration, rapidly progressive, and in need of urgent care. Airway: The path air follows to get into and out of the lungs. The mouth and nose are the normal entry and exit ports. Entering air then passes through the back of the throat (pharynx), continues through the voice box (larynx), down the trachea, and finally out the branching tubes known as bronchi. Alcohol abuse: Use of alcoholic beverages to excess, either on individual occasions ("binge drinking") or as a regular practice. For some individuals-children or pregnant women, for example-almost any amount of alcohol use may be legally considered "alcohol abuse," depending on local laws. Heavy alcohol abuse can cause physical damage and death. 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. 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. Ammonia: A colorless gas with a very sharp odor. Made both by humans and by nature, ammonia dissolves easily in water and evaporates quickly. Liquid ammonia is found in many household cleaners. Ammonia is irritating to the skin, eyes, nose, throat, and lungs. Exposure to high concentrations in the air can severely burn the skin, eyes, throat, or lungs. In extreme cases, blindness, lung damage, or death can occur. Breathing lower concentrations causes coughing and nose and throat irritation. Swallowing ammonia may burn the mouth, throat, and stomach. 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. Anoxia: 1. Strictly speaking, the absence of oxygen. 2. The near absence of oxygen. 3. Sometimes used loosely as a synonym for hypoxia. Anoxic: Pertaining to anoxia, an absence or near absence of oxygen. Ataxia: Wobbliness. Incoordination and unsteadiness due to the brain's failure to regulate the body's posture and regulate the strength and direction of limb movements. Ataxia is usually a consequence of disease in the brain, specifically in the cerebellum which lies beneath the back part of the cerebrum. Bacteria: Single-celled microorganisms which can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life). Birth defect: Any defect present in a baby at birth, irrespective of whether the defect is caused by a genetic factor or by prenatal events that are not genetic. Blood count: The calculated number of white or red blood cells (WBCs or RBCs) in a cubic millimeter of blood. Blood glucose: The main sugar that the body makes from the food in the diet. Glucose is carried through the bloodstream to provide energy to all cells in the body. Cells cannot use glucose without the help of insulin. 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". Blood sugar: Blood glucose. See also: High blood sugar; Low blood sugar. Bovine: Having to do with cows and cattle, as in bovine spongiform encephalopathy (mad cow disease), bovine tuberculosis, and bovine growth hormone. 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." Breathing: The process of respiration, during which air is inhaled into the lungs through the mouth or nose due to muscle contraction, and then exhaled due to muscle relaxation. Broca's area: An area of the cerebral motor cortex in the frontal lobe of the brain that is responsible for speech development. Damage to Broca's area can cause speech disorders, including apraxia and dyspraxia of speech. Cancer: An abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread). Carbon monoxide poisoning: Poisoning with carbon monoxide, a tasteless odorless gas that is a byproduct of combustion. Carbon monoxide acts as a poison by competing with oxygen for binding sites on hemoglobin, the molecule in red blood cells that carries oxygen from the lungs to the more remote tissues of the body and returns carbon dioxide from the tissues to the lungs. On inhalation, carbon monoxide binds to hemoglobin with a binding affinity 200--270 times greater than that of oxygen. Cardiopulmonary: Having to do with both the heart and lungs. Cardiopulmonary resuscitation: The emergency substitution of heart and lung action to restore life to someone who appears dead. The two main components of conventional cardiopulmonary resuscitation (CPR) are chest compression to make the heart pump and mouth-to-mouth ventilation to breath for the victim. Hands-only CPR is a form of resuscitation that involves continuous, rapid chest compressions only, and although effective, it is not as beneficial as conventional CPR in a patient who is not breathing. 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. 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. 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. Chest: The area of the body located between the neck and the abdomen. The chest contains the lungs, the heart and part of the aorta. The walls of the chest are supported by the dorsal vertebrae, the ribs, and the sternum. Chest pain: There are many causes of chest pain. One is angina which results from inadequate oxygen supply to the heart muscle. Angina can be caused by coronary artery disease or spasm of the coronary arteries. Chest pain can also be due to a heart attack (coronary occlusion) and other important diseases such as, for example, dissection of the aorta and a pulmonary embolism. Do not try to ignore chest pain and "work (or play) though it." Chest pain is a warning to seek medical attention. Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time. Chronic kidney failure: See: Chronic renal failure. Clinical trials: Trials to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects on large groups of people. Coma: A state of deep unarousable unconsciousness. 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. Computerized tomography: Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them in pictures. Congenital: Present at birth. A condition that is congenital is one that is present at birth. There are numerous uses of "congenital" in medicine. There are, for example, congenital abnormalities. (For more examples, see below.) CPR: Cardiopulmonary resuscitation. Also cardiac and pulmonary rehabilitation and computer-based patient records. Cyanide: Poisoning with cyanide, a rapidly acting, potentially deadly chemical that can exist as a colorless gas, such as hydrogen cyanide (HCN) or cyanogen chloride (CNCl), or a crystal form such as sodium cyanide (NaCN) or potassium cyanide (KCN). Cyanide sometimes is described as having a "bitter almond" smell, but it does not always give off an odor, and not everyone can detect this odor. Cyanide is also known by the military designations AN (for hydrogen cyanide) and CK (for cyanogen chloride). Dementia: Significant loss of intellectual abilities such as memory capacity, severe enough to interfere with social or occupational functioning. 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). 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. Dialysis: The process of cleansing the blood by passing it through a special machine. Dialysis is necessary when the kidneys are not able to filter the blood. Dialysis allows patients with kidney failure a chance to live productive lives. There are two types of dialysis: hemodialysis and peritoneal dialysis. Each type of dialysis has advantages and disadvantages. Patients can often choose the type of long term dialysis that best matches their needs. Dopamine: An important neurotransmitter (messenger) in the brain. 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. Encephalopathy: Disease, damage, or malfunction of the brain. In general, encephalopathy is manifested by an altered mental state that is sometimes accompanied by physical changes. Although numerous causes of encephalopathy are known, the majority of cases arise from infection, liver damage, anoxia, or kidney failure. The term encephalopathy is very broad and, in most cases, is preceded by various terms that describe the reason, cause, or special conditions of the patient that leads to brain malfunction. For example, anoxic encephalopathy means brain damage due to lack of oxygen, and hepatic encephalopathy means brain malfunction due to liver disease. Depending upon the cause and severity of the condition, symptoms may range from mild alterations in mental status to severe and potentially fatal manifestations such as dementia, seizures, and coma. Fetal distress: Compromise of the fetus during the antepartum period (before labor) or intrapartum period (birth process). The term "fetal distress" is commonly used to describe fetal hypoxia (low oxygen levels in the fetus). The concern with fetal hypoxia is it may result in fetal damage or death if not reversed or if the fetus is not promptly delivered. Fetus: The unborn offspring from the end of the 8th week after conception (when the major structures have formed) until birth. Up until the eighth week, the developing offspring is called an embryo. Frontal: In anatomy, pertaining to the forehead. As, for example, the frontal bone, frontal sinus, and frontal nerve. From the Latin "frons" meaning the forehead or brow. Fungi: Plural of fungus. 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. Genetic: Having to do with genes and genetic information. Glucose: The simple sugar (monosaccharide) that serves as the chief source of energy in the body. Glucose is the principal sugar the body makes. The body makes glucose from proteins, fats and, in largest part, carbohydrates. Glucose is carried to each cell through the bloodstream. Cells, however, cannot use glucose without the help of insulin. Glucose is also known as dextrose. Glutamine: An amino acid, one of the 20 building blocks of protein. Glutamine is present in plant and animal proteins. It can be synthesized by the body and is therefore not essential to the diet. Glutamine serves as an important carrier of ammonia and contributes it to the formation of urea and purines (which are essential to make DNA and RNA). Glutamine is broken down in the kidney. It was isolated in 1833 from beet juice but not synthesized until 1933. Symbol: Gln. Headache: A pain in the head with the pain being above the eyes or the ears, behind the head (occipital), or in the back of the upper neck. Headache, like chest pain or back ache, has many causes. 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. Hemoglobin: The oxygen-carrying pigment and predominant protein in the red blood cells. Hemoglobin forms an unstable, reversible bond with oxygen. In its oxygenated state it is called oxyhemoglobin and is bright red. In the reduced state it is called deoxyhemoglobin and is purple-blue. Hemorrhagic: Pertaining to bleeding or the abnormal flow of blood. Hepatic: Having to do with the liver. Pronounced hi-'pa-tik. From the Latin hepaticus derived from the Greek hepar meaning (not too surprisingly) the liver. Hepatic encephalopathy: Brain dysfunction directly due to liver dysfunction, most often recognized in advanced liver disease. Hepatic encephalopathy may cause disturbances of consciousness and progress to coma. Hepatitis: Inflammation of the liver from any cause. 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. Hyperglycemia: A high blood sugar. An elevated level specifically of the sugar glucose in the blood. Hypertensive: Having abnormally high blood pressure (hypertension). See also: Hypotensive; Normotensive. Hypertensive crisis: A severe and potentially life-threatening increase in blood pressure . A hypertensive crisis is a medical emergency. When the blood pressure rises to levels of 180/110 or greater, the blood vessels and organs may become damaged. This damage can be manifested as a number of conditions including stroke, heart attack, pulmonary edema (fluid in the lungs), a tear in the main artery of the body, the aorta (known as an aortic dissection), and eclampsia (during pregnancy). Hypoglycemia: Low blood sugar (glucose). When symptoms of hypoglycemia occur together with a documented blood glucose under 45 mg/dl, and the symptoms promptly resolve with the administration of glucose, the diagnosis of hypoglycemia can be made with some certainty. Hypoglycemia is only significant when it is associated with symptoms. Hyponatremia: An abnormally low concentration of sodium in the blood. Too little sodium can cause cells to malfunction, and extremely low sodium can be fatal. Hyponatremia has many causes including medications such as diuretics and antidepressants, hypothyroidism, cortisone deficiency (such as in Addison's disease), dehydration, vomiting or diarrhea, severe burns, kidney or heart failure, and cirrhosis. Hypotension: Any blood pressure that is below the normal expected for an individual in a given environment. Hypotension is the opposite of hypertension (abnormally high blood pressure). Hypotonia: Decreased tone of skeletal muscles. In a word, floppiness. Hypotonia is a common finding in cerebral palsy and other neuromuscular disorders. Untreated hypotonia can lead to hip dislocation and other problems. Treatment is via physical therapy. In some cases braces may be needed to permit a full range of movement despite hypotonia. Hypoxic: Pertaining to hypoxia, a subnormal concentration of oxygen. 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. 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. 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. Intervention: The act of intervening, interfering or interceding with the intent of modifying the outcome. In medicine, an intervention is usually undertaken to help treat or cure a condition. For example, early intervention may help children with autism to speak. "Acupuncture as a therapeutic intervention is widely practiced in the United States," according to the National Institutes of Health. From the Latin intervenire, to come between. Intestine: The long, tubelike organ in the abdomen that completes the process of digestion. It consists of the small and large intestines. Intubation: The process of putting a tube into a hollow organ or passageway, often into the airway. The opposite of intubation is extubation. 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. See the entire definition of Kidney Kidney transplant: Replacement of a diseased, damaged, or missing kidney with a donor kidney. Also called a renal transplant. Kuru: A slowly progressive fatal disease of the brain due to an infectious agent transmitted among people in Papua New Guinea by ritual cannibalism. Lethargy: 1. Abnormal drowsiness, stupor. 2. A state of indifference. 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. See the entire definition of Liver 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. Lobe: Part of an organ that appears to be separate in some way from the rest. A lobe may be demarcated from the rest of the organ by a fissure (crack), sulcus (groove), connective tissue or simply by its shape. For example, there are the frontal, parietal, temporal, and occipital lobes of the brain. Low blood pressure: Any blood pressure that is below the normal expected for an individual in a given environment. Low blood pressure is also referred to as hypotension. Low blood sugar: A low blood level of the sugar glucose. Also called hypoglycemia. 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. 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. Magnetic resonance imaging: A special radiology technique designed to image internal structures of the body using magnetism, radio waves, and a computer to produce the images of body structures. In magnetic resonance imaging (MRI), the scanner is a tube surrounded by a giant circular magnet. The patient is placed on a moveable bed that is inserted into the magnet. The magnet creates a strong magnetic field that aligns the protons of hydrogen atoms, which are then exposed to a beam of radio waves. This spins the various protons of the body, and they produce a faint signal that is detected by the receiver portion of the MRI scanner. A computer processes the receiver information, and an image is produced. The image and resolution is quite detailed and can detect tiny changes of structures within the body, particularly in the soft tissue, brain and spinal cord, abdomen and joints. Malabsorption: The impaired absorption by the intestines of nutrients from food. Malabsorption can be specific and involve sugars, fats, proteins, or vitamins. Alternatively, malabsorption can be general and nonspecific. 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. 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. Meninges: The three membranes that cover the brain and spinal cord (singular: meninx). Meningitis: Inflammation of the meninges, usually due to a bacterial infection but sometimes from viral, protozoan, or other causes (in some cases the cause cannot be determined). 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). 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. 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. MRI: Abbreviation and nickname for magnetic resonance imaging. For more information, see: Magnetic Resonance Imaging; Paul C. Lauterbur; Peter Mansfield. 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." Myelin: The fatty substance that covers and protects nerves. Myelin is a layered tissue that sheathes the axons (nerve fibers). This sheath around the axon acts like a conduit in an electrical system, ensuring that messages sent by axons are not lost en route. It allows efficient conduction of action potentials down the axon. Myelin consists of 70% lipids (cholesterol and phospholipid) and 30% proteins. It is produced by oligodendrocytes in the central nervous system. Naloxone: A drug that antagonizes morphine and other opiates. Naloxone is a pure opiate antagonist and prevents or reverses the effects of opioids including respiratory depression, sedation and hypotension. Sold under the brand name of Narcan and in combination with buprenorphine as Suboxone. Narcan: Brand name for naloxone. Narcotic: 1. A drug that causes insensibility or stupor. A narcotic induces narcosis, from the Greek "narke" for "numbness or torpor." Nausea: Nausea, is the urge to vomit. It can be brought by many causes including, systemic illnesses, such as influenza, medications, pain, and inner ear disease. When nausea and/or vomiting are persistent, or when they are accompanied by other severe symptoms such as abdominal pain, jaundice, fever, or bleeding, a physician should be consulted. Neck: The part of the body joining the head to the shoulders. Also, any narrow or constricted part of a bone or organ that joins its parts as, for example, the neck of the femur bone. 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. Neurological: Having to do with the nerves or the nervous system. Obtunded: Mentally dulled. A person may be obtunded due to head trauma. To obtund is to dull or blunt. From the Latin obtundere, to blunt. Occipital: 1. Pertaining to the occiput, the back of head. Organ: A relatively independent part of the body that carries out one or more special functions. The organs of the human body include the eye, ear, heart, lungs, and liver. Organ failure: The failure of an essential system in the body. Multiple organ failure is the failure of two or more systems, such as the cardiovascular, and renal systems, and is a common consequence of sepsis (the presence of bacteria in the bloods) and of shock (very low blood pressure). 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. Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors. Parietal: Adjective from the Latin "parietalis" meaning "belonging to the wall" that the ancient anatomists used to designate the wall, as of a body cavity. Placenta: A temporary organ joining the mother and fetus, the placenta transfers oxygen and nutrients from the mother to the fetus, and permits the release of carbon dioxide and waste products from the fetus. It is roughly disk-shaped, and at full term measures about seven inches in diameter and a bit less than two inches thick. The upper surface of the placenta is smooth, while the under surface is rough. The placenta is rich in blood vessels. Placenta previa: Location of the placenta in the lower part of the uterus (womb) so that the placenta partially or completely covers the cervix. Poison: Any substance that can cause severe distress or death if ingested, breathed in, or absorbed through the skin. Many substances that normally cause no problems, including water and most vitamins, can be poisonous if taken in too large of a quantity. Poison treatment depends on the substance: if there are treatment instructions on the substance's container and you are sure it contained no other item, follow those directions immediately. Always contact your nearest Poison Control Center if you are concerned about possible poison ingestion. Poisoning: Taking a substance that is injurious to health or can cause death. Poisoning is still a major hazard to children, despite child-resistant (and sometimes adult-resistant) packaging and dose-limits per container. Pregnancy: The state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long. Primary care: The "medical home" for a patient, ideally providing continuity and integration of health care. All family physicians and most pediatricians and internists are in primary care. The aims of primary care are to provide the patient with a broad spectrum of care, both preventive and curative, over a period of time and to coordinate all of the care the patient receives. Primary care provider: In insurance parlance, a physician chosen by or assigned to a patient, who both provides primary care and acts as a gatekeeper to control access to other medical services. Prion: A disease-causing agent that is neither bacterial nor fungal nor viral and contains no genetic material. A prion is a protein that occurs normally in a harmless form. By folding into an aberrant shape, the normal prion turns into a rogue agent. It then coopts other normal prions to become rogue prions. Prognosis: 1. The expected course of a disease. Progressive: Increasing in scope or severity. Advancing. Going forward. In medicine, a disease that is progressive is going from bad to worse. 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. Proteins: Large molecules 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. Recur: To occur again. To return. Any symptom (such as fatigue), any sign (such as a heart murmur), or any disease can recur. Recurrent: Back again. A recurrent fever is a fever that has returned after an intermission: a recrudescent fever. Relapse: The return of signs and symptoms of a disease after a patient has enjoyed a remission. For example, after treatment a patient with cancer of the colon went into remission with no sign or symptom of the tumor, remained in remission for 4 years, but then suffered a relapse and had to be treated once again for colon cancer. Renal: Having to do with the kidney. From the Latin renes (the kidneys), which gave the French les reins which mean both the kidneys and the lower back. Resuscitation: The procedure of restoring to life, as in cardiopulmonary resuscitation (CPR). Seizure: Uncontrolled electrical activity in the brain, which may produce a physical convulsion, minor physical signs, thought disturbances, or a combination of symptoms. Seizure disorders: One of a great many medical conditions that are characterized by episodes of uncontrolled electrical activity in the brain (seizures). Some seizure disorders are hereditary, but others are caused by birth defects or environmental hazards, such as lead poisoning. Seizure disorders are more likely to develop in patients who have other neurological disorders, psychiatric conditions, or immune-system problems. In some cases, uncontrolled seizures can cause brain damage, lowered intelligence, and permanent mental and physical impairment. Diagnosis is by observation, neurological examination, electroencephalogram (EEG), and in some cases more advanced brain imaging techniques. Treatment is usually by medication, although in difficult cases a special diet or brain surgery may be tried. Sensation: In medicine and physiology, sensation refers to the registration of an incoming (afferent) nerve impulse in that part of the brain called the sensorium, which is capable of such perception. Therefore, the awareness of a stimulus as a result of its perception by sensory receptors. (Sensory is here synonymous with sensation.) 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. Shortness of breath: Difficulty in breathing. Medically referred to as dyspnea. Shortness of breath can be caused by respiratory (breathing passages and lungs) or circulatory (heart and blood vessels) conditions. See also dyspnea. 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. Sodium: The major positive ion (cation) in fluid outside of cells. The chemical notation for sodium is Na+. When combined with chloride, the resulting substance is table salt. Spinal cord: The major column of nerve tissue that is connected to the brain and lies within the vertebral canal and from which the spinal nerves emerge. Thirty-one pairs of spinal nerves originate in the spinal cord: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. The spinal cord and the brain constitute the central nervous system (CNS). The spinal cord consists of nerve fibers that transmit impulses to and from the brain. Like the brain, the spinal cord is covered by three connective-tissue envelopes called the meninges. The space between the outer and middle envelopes is filled with cerebrospinal fluid (CSF), a clear colorless fluid that cushions the spinal cord against jarring shock. Also known simply as the cord. Spongiform: Resembling a sponge in being soft and full of cavities, as in as in transmissible spongiform encephalopathy. 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. 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. Temporal: 1. Pertaining to time, limited in time, temporary, or transient. Temporal lobe: The lobe of the cerebral hemisphere located down on the side just forward of the occipital lobe. The temporal lobe contains the auditory cortex which is responsible for hearing. It is also the site of the seizure activity characteristic of temporal-lobe epilepsy. Therapy: The treatment of disease. Thiamine: Vitamin B1. Thiamine (vitamin B1) acts as a coenzyme in the metabolism of the body. Deficiency of thiamine leads to beriberi, a syndrome characterized by inflammation of multiple nerves (polyneuritis), heart disease (cardiopathy), and edema (swelling). 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.) Tomography: The process for generating a tomogram, a two-dimensional image of a slice or section through a three-dimensional object. Tomography achieves this remarkable result by simply moving an x-ray source in one direction as the x-ray film is moved in the opposite direction during the exposure to sharpen structures in the focal plane, while structures in other planes appear blurred. The tomogram is the picture; the tomograph is the apparatus; and tomography is the process. Trachea: A tube-like portion of the breathing or "respiratory" tract that connects the "voice box" (larynx) with the bronchial parts of the lungs. See the entire definition of Trachea Transplant: The grafting of a tissue from one place to another, just as in botany a bud from one plant might be grafted onto the stem of another. The transplanting of tissue can be from one part of the patient to another (autologous transplantation), as in the case of a skin graft using the patient's own skin; or from one patient to another (allogenic transplantation), as in the case of transplanting a donor kidney into a recipient. Trauma: Any injury, whether physically or emotionally inflicted. "Trauma" has both a medical and a psychiatric definition. Medically, "trauma" refers to a serious or critical bodily injury, wound, or shock. This definition is often associated with trauma medicine practiced in emergency rooms and represents a popular view of the term. In psychiatry, "trauma" has assumed a different meaning and refers to an experience that is emotionally painful, distressful, or shocking, which often results in lasting mental and physical effects. Trimester: The nine months of pregnancy is traditionally divided into three trimesters: distinct periods of roughly three months in which different phases of fetal development take place. Tylenol: See: Acetaminophen. Umbilical cord: The cord that connects the developing embryo or fetus with the placenta and through which run the umbilical arteries and vein. The matrix (the substance) of the umbilical cord is known as Wharton's jelly and is a rich source of stem cells. At birth the umbilical cord measures about 20 inches (50 cm) in length. The cord is clamped and cut after birth and its residual tip forms the umbilicus (bellybutton). Unconscious: 1. Interruption of awareness of oneself and one's surroundings, lack of the ability to notice or respond to stimuli in the environment. A person may become unconscious due to oxygen deprivation, shock, central nervous system depressants such as alcohol and drugs, or injury. Urea: A nitrogen-containing substance normally cleared from the blood by the kidney into the urine. Diseases that compromise the function of the kidney often lead to increased blood levels of urea, as measured by the blood urea nitrogen (BUN) test. Uterus: The uterus (womb) is a hollow, pear-shaped organ located in a woman's lower abdomen between the bladder and the rectum. The narrow, lower portion of the uterus is the cervix; the broader, upper part is the corpus. The corpus is made up of two layers of tissue. See the entire definition of Uterus Ventilator: A ventilator is a machine which mechanically assists patients in the exchange of oxygen and carbon dioxide (sometimes referred to as artificial respiration). Viruses: Small living particles that can infect cells and change how the cells function. Infection with a virus can cause a person to develop symptoms. The disease and symptoms that are caused depend on the type of virus and the type of cells that are infected. 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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Encephalopathy
Mad Cow Disease and Variant Creutzfeldt-Jakob Disease »
Mad Cow Disease Overview
“Mad cow” is an infectious disease in the brain of cattle. Humans who become infected, usually by eating tissue from diseased cattle, will die of a similar brain disease that may develop over many years.
Abnormal proteins called prions (PRE-ons) are found in brain tissue of diseased cattle. Prions eat away at the brain and create tiny spongelike holes in parts of the brain. These so-called spongy holes cause slow deterioration within the cattle brain, and eventually symptoms affecting the whole body. Death follows. The scientific name for mad cow disease in cattle is called bovine spongiform encephalopathy (meaning sick brain) or BSE, meaning a sickness of the cow’s brain; when damaged brain tissue is viewed on a laboratory slide, it has a spongy appearance.
If humans eat diseased tissue from cattle, they may develop the human form of mad cow disease known as variant Creutzfeld...Read the Mad Cow Disease and Variant Creutzfeldt-Jakob Disease article »
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