Medical terms - Letter A (page 22) | MedicalVocabulary.org

Antiparallel

A term applied to two molecules that are side by side but run in opposite directions. The two strands of DNA are antiparallel. The head of one strand is always laid against the tail of the other strand of DNA
Antiparasitic

Effective in the treatment of parasites. For example, nitazoxanide (Alinis) is an antiparasitic medication used to treat diarrhea due to the intestinal parasite Giardia lamblia
Antiphospholipid antibody syndrome

Antiphospholipid antibody syndrome (APLS): An immune disorder characterized by the presence of abnormal antibodies in the blood associated with abnormal blood clotting, migraine headaches, recurrent pregnancy losses…
Antiprotozoal

Something that destroys protozoa or inhibits their growth and ability to reproduce. A few of the protozoa of medical importance include Plasmodium (the cause of malaria); Entamoeba histolytica (the cause of amebiasis…
Antiprotozoal drug

Something that destroys protozoa or inhibits their growth and ability to reproduce. A few of the protozoa of medical importance include Plasmodium (the cause of malaria); Entamoeba histolytica (the cause of amebiasis…
Antipsoriatic

Directed against psoriasis. Sunlight is antipsoriatic, as are a number of drugs
Antipsychotic

A medication (or another measure) that is believed to be effective in the treatment of psychosis. For example, aripiprazole (Abilify) is an antipsychotic medication used to treat schizophrenia
Antipyretic

Something that reduces fever or quells it. There are 3 classes of antipyretic medications that are sold OTC (over-the-counter) without prescription: > >Salicylates -- aspirin (acetylsalicylic acid), choline salicylate…
Antiretroviral

An agent or process effective against a retrovirus. For example, a drug to treat HIV
Antiretroviral therapy (ART)

Treatment that suppresses or stops a retrovirus. One of the retrovirus is the human immunodeficiency virus (HIV) that causes AIDS. Retroviruses are so named because they carry their genetic information in the form of…
Antisense

In molecular biology, the strand complementary to a coding sequence of a nucleic acid. Antisense DNA is the non-coding strand complementary to the coding strand in double-stranded DNA. The antisense strand serves as the…
Antisense DNA

DNA normally has two strands, i.e., the sense strand and the antisense strand. In double-stranded DNA, only one strand codes for the RNA that is translated into protein. This DNA strand is referred to as the antisense…
Antisense drug

A medication containing part of the non-coding strand of messenger RNA (mRNA), a key molecule involved in the translation of DNA into protein. Antisense drugs hybridize with and inactivate mRNA. This stops a particular…
Antisense mRNA

An mRNA (messenger RNA) transcript that is complementary to endogenous mRNA. Antisense mRNA is the noncoding strand complementary to the coding sequence of mRNA. Introducing a transgene coding for antisense mRNA is a…
Antisense-strand RNA virus

See: Negative-strand RNA virus
Antisepsis

Prevention of infection by inhibiting or arresting the growth and multiplication of germs (infectious agents). Antisepsis implies scrupulously clean and free of all living microorganisms. From the Greek roots anti-…
Antiseptic

Something that discourages the growth microorganisms. By contrast, aseptic refers to the absence of microorganisms
Antisocial personality

See: Antisocial personality disorder
Antisocial personality disorder

Antisocial personality disorder: A pervasive pattern of disregard for and violation of the rights of others and inability or unwillingness to conform to what are considered to be the norms of society. The disorder…
Antispasmodic

1) A medication that lowers the incidence of or prevents seizures. 2) A medication that lowers the incidence of or prevents muscle spasms
Antithymocyte globulin

An immunosuppressive agent that selectively destroys T lymphocytes. Antithymocyte globulin is the gamma globulin fraction of antiserum from animals that have been immunized against human thymocytes. It is a polyclonal…
Antithyroglobulin

An antibody directed against thyroglobulin which is a key protein in the thyroid gland essential to the production of thyroid hormones (thyroxine and triiodothyronine). Antithyroglobulin antibodies can damage the…
Antithyroid antibody

An antibody directed against the thyroid gland, a gland which produces thyroid hormones (such as, for example, thyroxine and triiodothyronine). Antithyroid antibodies can be associated with inflammation of the thyroid…
Antithyroid drug

A drug directed against the thyroid gland. The antithyroid drugs include carbimazole, methimazole, and propylthiouracil (PTU). These drugs are used to treat hyperthyroidism (overactivity of the thyroid gland) in order…
Antitoxin

An antibody capable of destroying microorganisms including viruses and bacteria. An antitoxin provides passive immunity. For example, if a child gets whooping cough (diphtheria), an antitoxin prepared in horses against…
Antivenin

Antibodies created in the blood of a horse or sheep when the animal is injected with snake venom. Antivenin acts by neutralizing snake venom that has entered the body. Also called antivenom, snake antivenin, or snake…
Antiviral

An agent that kills a virus or that suppresses its ability to replicate and, hence, inhibits its capability to multiply and reproduce. For example, amantadine (Symmetrel) is a synthetic antiviral. It acts by inhibiting…
Antiviral agent

An agent that kills viruses or suppresses their replication and, hence, inhibits their capability to multiply and reproduce. For example, amantadine (BRAND name: SYMMETREL) is a synthetic (man- made) drug that inhibits…
Anton Chekhov

See: Chekhov, Anton
Antonio Maria Valsalva

See: Antonio Maria Valsalva
Antonomasia

1. The substitution of a title for a proper name, as in addressing a physician as 'Doctor' or a nurse as 'Nurse.'2. The substitution of a personal name for a noun to designate a member of a group or class, as in calling…
Antonomastic

Concerning, pertaining to, or characteristic of antonomasia. See also: Antonomasia
Antonomasy

See: Antonomasia
Antro-duodenal motility study

Antro-duodenal motility study: An antro-duodenal motility study is a study for detecting and recording the contractions of the muscles of the stomach and the first part of the small intestine, the duodenum. It is…
Antrum

A general term for cavity or chamber which may have specific meaning in reference certain organs or sites in the body. The antrum of the stomach (gastric antrum) is a portion before the outlet which is lined by mucosa…
Ants, fire

Originally from S. America. Among the worst insect pests ever to invade the U.S. Red or yellowish ants of small-to-medium size with a severe sting that burns like fire. They normally feed on small insects but, with…
Ants, velvet

Ommon in most parts of the world including the Southern and Southwestern U.S., velvet ants are not true ants but rather parasitic wasps. Their sting can trigger allergic reactions. Avoidance, prompt treatment and, in…
ANUG (acute necrotizing ulcerative gingivitis)

This is trench mouth, a progressive painful infection with ulceration, swelling and sloughing off of dead tissue from the mouth and throat due to the spread of infection from the gums. Certain germs (including fusiform…
Anus

The opening of the rectum to the outside of the body. The word 'anus' comes straight from the Latin. It referred to the same structure to the Romans. It also meant a 'ring' in the sense of an encirclement which was…
Anus, imperforate

A congenital malformation (a birth defect) in which the rectum is a blind alley (a cul-de-sac) and there is no anus. The anus is imperforate in the sense that the normal perforation we call the anus is absent. The end…
Anvil

The incus
ANXA1

Annexin A1
Anxiety

Anxiety: A feeling of apprehension and fear characterized by physical symptoms such as palpitations, sweating, and feelings of stress. Anxiety disorders are serious medical illnesses that affect approximately 19 million…
Anxiety disorder

A chronic condition characterized by an excessive and persistent sense of apprehension with physical symptoms such as sweating, palpitations, and feelings of stress. Anxiety disorders have biological and environmental…
Anxiety disorder, social

Excessive fear of embarrassment in social situations that is extremely intrusive and can have debilitating effects on personal and professional relationships. Also called social phobia. Phobias are persistent…
AOA

Abbreviation for Alpha Omega Alpha, the medical honor society, the medical school equivalent of Phi Beta Kappa, in the United States and Canada. Membership is by election for distinguished academic achievement. Medical…
AOM

Acute otitis media, a middle ear infection of abrupt onset
Aorta

The largest artery in the body, the aorta arises from the left ventricle of the heart, goes up (ascends) a little ways, bends over (arches), then goes down (descends) through the chest and through the abdomen to where…
Aorta, abdominal

The abdominal aorta is the final section of the aorta, the largest artery in the body. It is a continuation of the thoracic aorta. It begins at the diaphragm, and runs down to the point where it ends (by splitting in…
Aorta, ascending

The ascending aorta is the first section of the aorta, the largest artery in the body. The ascending aorta starts from the left ventricle of the heart and extends to the arch (the bend) of the aorta. The right and left…