Definitions

abdominal cavity

The superior portion of the abdominopelvic cavity.

abdominal region

One of the anterior regions of the trunk.

abdominopelvic cavity

A ventral cavity consisting of the abdominal and pelvic cavities. It contains digestive, urinary, and reproductive organs.

abduction

Directional term meaning to move away from the median or middle line of the body.

abnormal psychology

The study and treatment of behaviors that are outside of normal and are detrimental to the person or society. These maladaptive behaviors range from occasional difficulty coping with stress, to bizarre actions and beliefs, to total withdrawal.

ABO system

The major system of blood typing.

abortifacient

Medication that terminates a pregnancy.

abrasion

Scraping away a portion of the surface of the skin. Performed to remove acne scars, tattoos, and scar tissue.

abruptio placentae

Emergency condition in which the placenta tears away from the uterine wall before the 20th week of pregnancy. Requires immediate delivery of the baby.

abscess

Swelling of soft tissues of the jaw as a result of infection.

absence seizure

Type of epileptic seizure that lasts only a few seconds to half a minute, characterized by a loss of awareness and an absence of activity. It is also called a petit mal seizure.

acapnia

Lack of carbon dioxide.

accessory organs

The accessory organs to the digestive system consists of the organs that are part of the system, but not part of the continuous tube from mouth to anus. The accessory organs are the liver, pancreas, gall bladder, and salivary glands.

accommodation (Acc)

Ability of the eye to adjust to variations in distance.

ACE inhibitor drugs

Medication that produces vasodilation and decreases blood pressure.

achromatopsia

Condition of color blindness; more common in males.

acidosis

Excessive acidity of body fluids due to the accumulation of acids, as in diabetic acidosis.

acne

Inflammatory disease of the sebaceous glands and hair follicles that results in papules and pustules.

acne rosacea

Hypertrophy of sebaceous glands causing thickened skin generally on the nose, forehead, and cheeks.

acne vulgaris

A common form of acne occurring in adolescence from an oversecretion of the oil glands. It is characterized by papules, pustules, blackheads, and whiteheads.

acoustic

Pertaining to hearing.

acoustic neuroma

Benign tumor of the eighth cranial nerve sheath, which can cause symptoms from pressure being exerted on tissues.

acquired immunity

The protective response of the body to a specific pathogen.

acquired immunodeficiency syndrome (AIDS) I

Disease that involves a defect in the cell-mediated immunity system. A syndrome of opportunistic infections that occur in the final stages of infection with the human immunodeficiency virus (HIV).

acquired immunodeficiency syndrome (AIDS) II

This virus attacks T4 lymphocytes and destroys them, which reduces the person's ability to fight infection.

acromegaly

Chronic disease of adults that results in an elongation and enlargement of the bones of the head and extremities. There can also be mood changes.

action

The type of movement a muscle produces.

active acquired immunity

Immunity developing after direct exposure to a pathogen.