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 laceration.
Abortifacient
/æbôr'tifà'shænt/ a
drug or substance that causes abortion.
Abrosia
/æbrò'zhæ/ a state of fasting or not eating food. See
also anorexia.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 alkalosis.
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 adhesiotomy,
intestinal
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 child.
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 piebald, vitiligo.
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 chronic
alcoholism.
Aldosterone
/al'dòstæròn',aldos'tæròn/,
a steroid hormone made by the adrenal cortex that controls sodium
and potassium in the blood.
Alimentary
canal (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 acidosis.
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 allergy
testing, immunoglobulin.
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 hypothalamic
amenorrhea, postpill
amenorrhea.-amenorrheic, adj.
Amilial
a disease in some families and not in others. It is usually but not
always hereditary. Compare acquired,
congenital,
hereditary.hereditary
having to do with a feature, condition, or disease passed down from
parent to offspring; inborn; inherited. Compare acquired,
congenital,
familial.
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.
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 anodyne. See also pain
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 physiology.
4. archaic. dissection of a body.
Anatomic
crown
the part of a tooth covered by dental enamel. Compare artificial
crown, clinical
crown, partial 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 neural
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 posterior.
See also ventral.
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 paracentesis.-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 allergic
asthma, asthma in children, intrinsic
asthma, organic
dust, status 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 osteoarthritis,
rheu
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 artificial
respiration.-asphyxiate, v., asphyxiated, adj.
Astragalus
See talus.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 hypertrophic catarrh. See
also catarrh.
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: -atrophic, adj. aging.
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 oligospermia.