Abiotrophy (n)
Degeneration or loss of function without apparent cause. For example, retinal abiotrophy is progressive degeneration of the retina leading to impaired vision, occurring in genetic disorders such as retinitis pigmentosa.

Ablatio (n)
Separation; abruption. See detached retina (ablatio retinae)

Ablation (n)
The removal of tissue, a part of the body, or an abnormal growth, usually by cutting. See also endometrial ablation.

Ablepharia (n) Absence of or reduction in the size of the eyelids

Ablepsia (n) An obsolete term for blindness

Abortifacient (n) A drug that induces abortion or miscarriage. See prostaglandin

Abortion
The expulsion or removal of an embryo or fetus from the uterus at a stage of pregnancy when it is incapable of independent survival (i.e. at any time between conception and the 24th week of the pregnancy). In threatened abortion there is abdominal pain and bleeding from the uterus but the fetus is still alive. Once the fetus is dead abortion becomes inevitable. Abortion is incomplete so long as the uterus still contains some of the fetus or its membranes. Abortion may be spontaneous (a miscarriage) or it may be induced for medical or social reasons ( termination of pregnancy). Habitual abortion is the occurrence of three consecutive pregnancy losses before 20 weeks’ of gestation with fetuses weighing under 500grams. The presence of a uterine abnormality, such as bicornuate uterus or cervical incompetence, may account for 10-15% of recurrent abortions. After January 1973, induced abortion during the first three months of pregnancy became legal in the U.S. requiring only agreement between the woman and her doctor. During the remaining six months, voluntary termination of a pregnancy may be permitted under terms of state laws. Methods in current use include “salting out” in which saline solution is injected through the cervix into the membranes surrounding the fetus; vacuum aspiration of the products of conception through a thin cannula; dilation and curettage; opening the womb through an abdominal incision (hysterectomy); or the use of prostaglandin or other drugs to induce premature labor. Termination carries little risk early in pregnancy, but complications are more likely after the 13th week. Nonmedical people make a distinction between abortion and miscarriage, the former being a procedure deliberately carried out to end the pregnancy, the latter being an accidental occurrence. The medical profession increasingly recognizes this useful distinction.

Abortus (n)
A fetus, weighing less than 500 grams, that is expelled from the mother’s body either dead or incapable of surviving.
Abrasion (n)
1. A graze: a minor wound in which the surface of the skin or a mucous membrane is worn away by rubbing or scraping.
2. The wearing of the teeth, particularly at the necks by overvigoroous brushing. It is frequently enhanced by erosion
3. Any rubbing or scraping action that produces surface wear.

Abreaction
The release of strong emotion associated with a buried memory. While this can happen spontaneously, it is usually deliberately produced by a therapist using psychotherapy, hypnosis, or drugs such as thiopental. The technique is used as a treatment for conversion disorder, anxiety state, and other neurotic conditions, especially when they are thought to be caused by repression of memories or emotions.