A

 

Abdominal pregnancy       a pregnancy in which the fetus develops outside of the uterus. This can occur because of a defect in the fallopian tube or uterus. This is rare. Diagnosis is made by ultrasound or x-ray films. The placenta and fetus must be removed.

 

Abdominal regions       nine parts of the belly, made by four imaginary lines, in a tic-tac-toe pattern.

 

Abiotrophy  /ab'è×ot'ræfè/     an early loss of energy or the breakdown of certain parts of the body, usually because of a lack of certain foods. -abiotrophic  /ab'è×ætrò'fik/adj.

 

Abiosis  /ab'è×ò'sis/     a lifeless condition or one that is not compatible with life.

 

Ablation  /ablà'shæn/     the act of cutting off any part of the body, or removal of a growth or damaged tissue.

 

Abor       the time and processes that occur during childbirth from the beginning of cervical dilatation to the delivery of the placenta, or after-birth.

 

Abortion       a spontaneous or deliberate ending of pregnancy before the fetus can be expected to live. Kinds of abortion include habitual abortion, infected abortion, septic abortion, threatened abortion, voluntary abortion.   Also see: Septic abortion       

 

 

Abrade  /æbràd/     to remove the top layer or other layers of skin, usually by scraping or rubbing.

 

Abrasion       a scraping or rubbing away of a surface. It may be theresult of trauma, as a skinned knee. Compare 10415laceration.

 

Abortifacient  /æbôr'tifà'shænt/     a drug or substance that causes abortion.

 

Abrosia  /æbrò'zhæ/     a state of fasting or not eating food. See also 1192anorexia.abcess        

 

Abscess       a hole filled with pus and surrounded by swollen tissue. It forms as a result of a local infection. Healing usually occurs after it drains or is opened.

 

Absorbent dressing       a dressing placed on a wound or cut to absorb fluid or other drainage.

 

Acantha  /ækan'thæ/     a spine, as the spine like projection of a backbone (vertebra).

 

Acardia  /akaär'dè×æ/     a rare birth defect in which the heart is absent. A cardiotro

 

Achondrogenesis  /àkon'dròjen'æsis/     a form of dwarfism characterized by very short arms and legs and excess fluid in the tissues of the head and trunk. It is transmitted genetically.

 

Achylia  /àkí'lè×æ/     a lack of or not enough hydrochloric acid and pepsinogen, chemicals needed for digesting food in the stomach.

 

Acidosis       an abnormal increase in hydrogen in the body from too much acid or the loss of base. The many forms of acidosis are named for the cause. For example, renal tubular acidosis results when the kidney fails to get rid of hydrogen or collect bicarbonate. Compare 760alkalosis.

 

Acidulous  /æsid'yælæs/     slightly acidic or sour.

 

Acne  /ak'nè/     a breakout of pimples. It usually occurs in or near the oil glands on the face, neck, shoulders, and upper back. Its cause is not known but involves bacteria that bother the skin. Treatment includes antibiotics, topical vitamin A, benzyl benzoate, and dermabrasion.

 

Acoustic       referring to sound or hearing. Also acoustical.

 

Acoria  /akôr'è×æ/     a state of always being hungry even when the desire for food is small.

 

Adipocele  /ad'ipòsèl'/     a loop of an organ or tissue through an opening and holding fat or fatty tissue. Also called lipocele.

 

Adenosine triphosphatase (ATPase)       an enzyme in skeletal muscles that causes the splitting of adenosine triphosphate to adenosine diphosphate and inorganic phosphate to provide energy to muscles.

 

Adhesion  /adhè'zhæn/     a band of scar tissue that binds two surfaces normally apart from each other. They are most commonly found in the belly after surgery, swelling, or injury. More surgery may be needed to pull apart the tissues. See also 466adhesiotomy, 9891intestinal obstruction.

 

Adrenalin       a trademark for a drug used to treat severe allergies, spasms of the large air channels of the lungs (bronchial spasms), and a clogged nose and throat (epinephrine).

 

Adrenaline       See 6758epinephrine.epinephrine  /ep'ænef'rin/     a drug that stimulates the adrenal glands and narrows the blood vessels. It is used to treat stuffy nose, to help extreme allergic reactions, and as a local anesthetic.

 

Adult       1. one who is fully physically mature and who has reached the mental potential and the emotional growth typical of a mature person. 2. a person who has reached full legal age. Compare 3778child.

 

Agoraphobia  /ag'æræ-/     mental defect in which the patient is afraid to be alone in an open, crowded, or public place, as a field, tunnel, bridge, busy street, or store, where escape may be hard or help may not be at hand. The disorder can sometimes be treated with success through psychiatric help.

 

Alba  /al'bæ/      a Latin term for "white," as in linea alba.

 

Albinism  /al'biniz'æm/     a birth defect marked by partial or total lack of pigment in the body. Total albinos have pale skin that does not tan, white hair, pink eyes, rapid, eye movement they cannot control (nystagmus), uneven eye curvature (astigmatism), and a response to light (photophobia). Compare 13626piebald, 18488vitiligo.

 

Albumin  /albyö'min/     a protein found in almost all animal tissues and in many plant tissues. Amounts and types of albumin in urine, blood, and other body tissues form the basis of many laboratory tests.

 

Alcoholism       the extreme dependence on alcohol that is marked by bad behaviors. It is a long-term illness that starts slowly and may occur at any age. The most frequent medical problems are mental changes and breakdown (cirrhosis) of the liver. The problems are worse when not enough food has been eaten. Patients may suffer from belly problems (gastritis), nerve damage, hearing things that are not there, and heart problems. Suddenly not drinking causes weakness, sweating, and very quick reflexes. The severe form of quitting is called delirium tremens. Caution must be used in giving drugs to the patient, because interactions with alcohol are common. The treatment of alcoholism consists of mental therapy (especially group therapy, as in Alcoholics Anonymous), electroshock treatments, or drugs, as disulfiram, that cause one to not want any alcohol. acute alcoholism       being drunk from too much alcohol. Symptoms are tremors, daze, loss of good movement, and often nausea, loss of water, and headache. Compare 4012chronic alcoholism.

 

Aldosterone  /al'dòstæròn',aldos'tæròn/,     a steroid hormone made by the adrenal cortex that controls sodium and potassium in the blood.

 

Alimentary canal 5823(digestive tract).  a muscular tube, about 30 feet (9 meters) long, which extends from the mouth to the anus. It includes the mouth, throat, stomach, small intestine, and large intestine. The tube, which is part of the digestive system of the body, includes several organs that release substances for digesting food.

 

Alkalosis  /al'kælò'sis/     a disorder of body fluids in which the pH level is greater than 7.44. Alkalosis of the lungs may be caused by too much air coming into the lungs (hyperventilation). Treatment of alkalosis restores the normal acid-base balance. Compare 218acidosis.

 

Allergy       a reaction to generally harmless antigens. More than 20 million Americans have allergic reactions to cigarette smoke, house dust, and pollens. Nasal irritation (allergic rhinitis), which is caused by allergens in the air, affects mostly young children and adolescents but occurs in all age groups. Allergies are labeled according to how the body's cells react to the allergen. Allergies are also divided into those that cause responses right away and those that cause delayed responses. Those allergic reactions that occur right away release substances into the blood flow, as histamine. Delayed allergic reactions, as skin rash or poison ivy, may take many days to show up. Some common symptoms of allergy are lung congestion, allergic eye swelling, fluid buildup, fever, itching, and vomiting. Severe allergic reactions can cause shock and death. Symptoms that last a short time, as those of hay fever, bee stings, and itching, can be treated with steroid drugs. When allergic reactions are life-threatening, steroids may be given in the vein. For milder diseases, as hay fever, antihistamines are usually given. See also 783allergy testing, 9460immunoglobulin.

 

Aloe  /al'ò/     the juice of the varied species of Aloe plants. Once used to empty the bowels, the practice has been stopped because it often causes severe cramps. The most common use of aloe today is for mild skin burns and rash.

 

Alveoli       small pockets that stick out along the walls of alveolar sacs in the lung. This is where carbon dioxide leaves the blood and oxygen is taken on by the blood.

 

Amenorrhea  /à'menærè'æ/     the absence of the monthly flow of blood and discharge of mucous tissues from the uterus through the vagina (menstruation). Amenorrhea is normal before sexual maturity, during pregnancy, after menopause, and in other phases of the menstrual cycle. Abnormal amenorrhea is caused by malfunction of the hypothalamus gland, pituitary gland, ovary, or uterus. It can be caused by drugs, or by removal of both ovaries or the uterus. A woman born without a uterus will not menstruate. Primary amenorrhea is the failure of menstrual cycles to begin. Secondary amenorrhea is the stopping of menstrual cycles once they have begun to occur. See also 9313hypothalamic amenorrhea, 13942postpill amenorrhea.-amenorrheic, adj.

 

Amilial       a disease in some families and not in others. It is usually but not always hereditary. Compare 261acquired, 4651congenital, 8765hereditary.hereditary       having to do with a feature, condition, or disease passed down from parent to offspring; inborn; inherited. Compare 261acquired, 4651congenital, 7213familial.

 

Amine pump        informal. a system in some nerve endings that absorbs epinephrine, a chemical of the nervous system. Bad reactions to some drugs, as antidepressants, block this. This causes a large amount of another chemical, norepinephrine, in heart tissue, resulting in heart rhythm disorders. See also monoamine oxidase inhibitor.

 

Aminocentesis    n., pl.  ses . surgical procedure of withdrawing  fluid from pregnant woman for genetic diagnosis of fetus.

 

Amniotic fluid  /am'nè×ot'ik/     a liquid made by the amnion and the fetus. It usually totals about 1,500 ml (a little more than 1 quarts) at 9 months. It surrounds the fetus during pregnancy, providing it with protection. It is swallowed, processed, and excreted as fetal urine at a rate of 50 ml (more than 2 ounces) every hour. Amniotic fluid is clear, though cells and fat give it a cloudy look.

 

Amphetamines       a group of drugs that works on the nervous system. These include amphetamine dextroamphetamine and methamphetamine. These drugs are abused by some people because they cause one to stay awake and feel great. Abuse causes the user to act driven, feel fearful, hear and see things that are not there, and consider suicide. They have street names, as black beauties, lid poppers, pep pills, and speed.

 

Amyloid       1.  referring to or resembling starch.  2.  a starchlike protein deposited in some tissues during certain diseases, such as amyloidosis, rheumatoid arthritis, and tuberculosis.

 

Anaerobe  /aner'òb/     a microorganism that grows and lives without oxygen. An example is Clostridium botulinum, which causes botulism. Anaerobes are found throughout nature and in the body. 1020

 

Anaerobic   /an'ærò'bik/     1. referring to the absence of air or oxygen. 2. able to grow and live without air or oxygen.

 

Anal reflex       a nerve reflex caused by stroking the skin around the anus. This should result in a contraction of the anal muscle (sphincter). This reflex may be lost in a nerve (neurological) disease.

 

Analgesic  /an'æljè'zik/     a drug that relieves pain. There are two kinds. One causes a stupor and is habit-forming (narcotic). The other lacks these side effects. Narcotics are usually given for severe pain. Compare 1181anodyne. See also 12928pain intervention.

 

Anatomy       1. the study of structures and organs of the body. Kinds of anatomy are applied anatomy, comparative anatomy, descriptive anatomy, gross anatomy, microscopic anatomy, surface anatomy. 2. the structure of an organism. 3. a text on anatomy. Compare 13608physiology. 4. archaic. dissection of a body.

 

Anatomic crown       the part of a tooth covered by dental enamel. Compare 1615artificial crown, 4203clinical crown, 13170partial crown.

 

Anencephaly  /an'ensef'ælè/     a birth defect in which there is no brain or spinal cord, the skull does not close, and the spinal canal remains a groove. Carried on the genes, it can be found early in pregnancy by looking at the amniotic fluid (amniocentesis). See also 12145neural tube defect.

 

Aneurysm  /an'yõriz'æm/     a bulging of the wall of a blood vessel, usually caused by hardening of the arteries (atherosclerosis) and high blood pressure (hypertension). It is sometimes caused by injury, infection, or an inherited weakness in the vessel wall. Aneurysms are most dangerous in the large artery of the heart (aorta). They also occur in smaller vessels and are common in the legs of older patients. A sign of an arterial aneurysm is a pulsating swelling. It makes a blowing murmur that can be heard with a stethoscope. An aneurysm may break open and cause bleeding, or clots may form in the pouch and block smaller vessels. Kinds of aneurysms include aortic aneurysm, bacterial aneurysm, berry aneurysm, cerebral aneurysm, compound aneurysm, dissecting aneurysm, fusiform aneurysm, mycotic aneurysm, racemose aneurysm, Rasmussen's aneurysm, saccular aneurysm, varicose aneurysm, ventricular aneurysm.-aneurysmal, adj.

 

Angina  /anjí'næ, an'jinæ/     1. a cramping chest pain and choking feeling caused by lack of oxygen to the heart muscle (angina pectoris). 2. a symptom of some diseases that is known by a feeling of choking, suffocation, or crushing pressure and pain. Kinds of angina are intestinal angina, Ludwig's angina, Prinzmetal's angina, streptococcal angina.-anginal, adj.

 

Anoint , v. put oil, etc., on, as in  consecration.

 

Anterior (A)       the front of a structure or a part facing toward the front. Compare 13904posterior. See also 18291ventral.

 

Antidote  /an'tidòt/     a drug or other substance that stops the action of a poison. An antidote may coat the stomach. This will keep the poison from being soaked up. It may also work to oppose the action of the poison, as giving a relaxing drug to a patient who has taken a large amount of a stimulant.

 

Antigen  /an'tijæn/     a substance foreign to the body, often a protein. It causes the body to form an antibody that responds only to that antigen. Antigens can cause allergic reactions in some people.

 

Antimony  /an'tæmònè/     a chemical element that occurs in nature, both free and as a salt. Its symbol is sb. Its atomic number is 51; its atomic weight is 121.8. Antimony is a bluish metal that has a crystal structure. Antimony compounds are used to treat parasite infections, as filariasis, leishmaniasis, schistosomiasis, and trypanosomiasis. It is also used to bring on vomiting in cases of poisoning.

 

Antipathy , n., pl. thies.  dislike; aversion

 

Antitoxin       an antiserum that is often made from the serum of horses that have immunity against a certain organism. Examples of antitoxins are botulism antitoxin given to patients who have a type of food poisoning (botulism), and tetanus and diphtheria antitoxins which are given to prevent those infections.

 

Apathetic hyperthyroidism       a form of excess thyroid production that tends to affect mainly older adults, who have stereotyped "senile" physical features and are apathetic and inactive rather than overactive in behavior. Medical treatment not only restores normal behavioral activity but also results in a loss of wrinkles and a younger physical appearance. Untreated, the patient is likely to succumb to the effects of stress or acute illness.

 

Aperture       an opening in an object or structure.

 

Aphasia  /æfà'zhæ/   (Broca's area)  a nerve defect in which there are problems with speaking or speech is lost. It is due to an injury to certain areas of the brain. There are many forms and degrees of aphasia. For example, a patient with aphasia may be able to speak but not to form words that can be understood. The patient may be able to understand speech and writing and form thoughts but not be able to speak. Aphasia may be the result of a severe head injury, lack of oxygen, or stroke. It is sometimes short term, as when a swelling in the brain goes down and language returns. Constant hard work and practice by the patient and the patient's family have helped to restore normal speaking ability.

 

Apoplexy  /ap'æplek'sè/      obsolete. a stroke that results in paralysis.

 

Appendage       an extra piece that is attached to a part or organ. Also called appendix.

 

Aqueous , adj. of or like water.

 

Ascites  /æsí'tèz/     an abnormal pooling of fluid in the abdominal cavity containing large amounts of protein and other cells. Ascites is usually noticed when more than one pint (500 ml) of fluid has collected. The condition may lead to general abdominal swelling, dilution of the blood, or less urinary output. The most common cause is liver disease (cirrhosis). However, ascites can be caused by cancer, kidney disease, congestive heart failure, or other diseases. The fluid can be removed with a needle (paracentesis). This relieves pain and improves breathing and organ function. See also 13057paracentesis.-ascitic, adj.

 

Asthma  /az'mæ/     a lung disorder marked by attacks of breathing difficulty, wheezing, coughing, and thick mucus coming from the lungs. The episodes may be started by breathing foreign substances (allergens) or pollutants, infection, vigorous exercise, or emotional stress. Treatment includes getting rid of the cause if possible. Sprays or wideners of the bronchi taken by mouth, and steroid drugs are also used. Certain drugs must not be used by persons with asthma (for example, some of the drugs for treating circulatory disease [beta-adrenergic drugs], barbiturates, and narcotics). Repeated attacks often result in shortness of breath (emphysema) and permanent obstructive lung disease. Also called bronchial asthma. See also 774allergic asthma, 1724asthma in children, 9978intrinsic asthma, 12694organic dust, 16278status asthmaticus.

 

Areola  /arè'òlæ/     pl. areolae, 1. a small space or a cavity within a tissue. 2. a circular area of a different color surrounding a feature, as the discolored skin around a lesion with pus (pustule). 3. the part of the iris around the pupil.

 

Arsenic (As)  /är'sænik/     an element that occurs throughout the earth's crust in metal arsenides, arsenious sulfides, and arsenious oxides. Its atomic number is 33; its atomic weight is 74.91. This element has been used for centuries as a drug and as a poison. It continues to have limited use in some drugs used to treat tropical disease (trypanosomiasis), as melarsoprol and tryparsamide. The introduction of drugs without arsenic that have less dangerous side effects has greatly reduced its use. The large amount of arsenic in the world places it in the food chain. Many compounds with arsenic are used as dyes, pesticides, herbicides, and feed additives for poultry and livestock. Fruit, vegetables, fish, and shellfish have significant concentrations of arsenic. The average daily human consumption of this element is about 900 micrograms. Most is consumed in food and water. The average concentration in the human adult is about 20 mg. It is stored mainly in the liver, the kidney, the stomach and intestines, and the lungs. Small amounts are found in the muscles and nerves. Long-term exposure to inorganic arsenic may cause severe damage to the lining of the stomach and intestines, kidneys, nervous system, bone marrow, liver, and blood system. Small doses of inorganic arsenic cause mild widening of the blood vessels. Larger doses lead to widening of the blood capillaries, heart disorders, and smaller blood volume. Studies show a strong link between the amount and length of time of arsenic exposure and lung cancer in metal workers. Federal laws on arsenic levels in food and industry have greatly lessened the number of arsenic poisonings.-arsenic  /ärsen'ik/, arsenical, adj. , n. 1. metallic element.  2. poisonous powder.

 

Arteriosclerosis       a common disorder of the arteries. It is marked by thickening, loss of elasticity, and hardening of the walls through calcium. This results in less blood supply, especially to the brain and legs. The condition often develops with aging. It also often occurs with high blood pressure, kidney disease, hardening of the connective tissues (scleroderma), diabetes, and excess of lipids in the blood (hyperlipidemia). Symptoms include leg cramps when walking (intermittent claudication), changes in skin temperature and color, altered pulses, headache, dizziness, and memory defects. Drugs to widen the blood vessels and exercise to stimulate circulation may relieve symptoms of arteriosclerosis. However, there is no specific treatment for the disorder. Kinds of arteriosclerosis are atherosclerosis, Mönckeberg's arteriosclerosis.

 

Arthritis  /ärthrí'tis/     any swelling of the joints, marked by pain and swelling. See also 12769osteoarthritis, 15069rheu

 

Asphyxia  /asfik'sè×æ/     severe oxygen lack. It leads to blood with low oxygen content, loss of consciousness, and, if not corrected, death. Some of the more common causes of asphyxia are drowning, electric shock, breathing vomit, and a foreign body stuck in the breathing tract. Breathing toxic gas or smoke, and poisoning are other causes. Artificial respiration and oxygen are promptly given to avoid damage to the brain. See 1627artificial respiration.-asphyxiate, v., asphyxiated, adj.

 

Astragalus       See 16823talus.alus  /tà'læs/, pl. tali,     the second largest bone of the ankle. It is made up of a body, neck, and head. Also called ankle bone, astragalus.

 

Atavism  /at'æviz'æm/     traits or characteristics in a person that are more like those of a grandparent or earlier ancestor than like the parents. Atavistic data may offer hints of genetic or family health factors to a physician.-atavistic, adj.

 

Atelectasis  /at'ilek'tæsis/     an abnormal condition marked by the collapse of lung tissue. This prevents the breathing exchange of carbon dioxide and oxygen by the blood. Symptoms include lessened breath sounds, fever, and more difficulty in breathing. The condition may be caused by obstruction of the major airways and bronchioles. It may also be caused by pressure on the lung from fluid or air in the area around the lungs (pleural space), or by pressure from a tumor outside the lung. Loss of lung tissue may cause increased heart rate, higher blood pressure, and faster breathing.

 

Atrium  /à'trè×æm/     pl. atria, a chamber or cavity, as the right and left atria of the heart or the nasal cavity.

 

Atrophic catarrh       an abnormal condition marked by swelling and discharge from the nose. It goes together with the loss of mucous membranes. Compare 9219hypertrophic catarrh. See also 3373catarrh.

 

Atrophy  /at'ræfè/     a wasting or loss of size of a part of the body because of disease or other influences. A muscle may atrophy because of lack of physical exercise. Nervous system or muscle disease are other causes. Cells of the brain and nervous system may atrophy in old age because of restricted blood flow to those areas. Compare to: 618aging.-atrophic, adj.

 

 

Auscultation  /ôskæltà'shæn/     the act of listening for sounds within the body to evaluate the condition of the heart, lungs, intestines, or other organs or to hear the fetal heart beat. Auscultation may be done with the ear alone. However, usually a stethoscope is used. The frequency, intensity, duration, and quality of the sounds are noted. During auscultation of the chest, the patient usually sits upright. He or she breathes slowly and deeply through the mouth. The front and back of the chest are auscultated from top to bottom. The sounds of the right and left sides are compared. The heart and stomach may be auscultated with the patient lying down or sitting upright.-auscultate, v.

 

Axilla  /aksil'æ/     pl. axillae, a pyramid-shaped space forming the underside of the shoulder between the upper part of the arm and the side of the chest. Also called armpit.

 

 

Azoospermia  /àzò'æspur'mè×æ/     lack of sperm in the semen. It may be caused by dysfunction of the testicles or by blockage of the tubes in which sperm is stored (epididymis). It may also be caused by vasectomy. Infertility but not impotence is linked to azoospermia. Compare 12570oligospermia.