Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «A»:
Afterbirth: The placenta + the fetal membranes that are
normally expelled from the uterus after the birth of the baby. Hence, the
"afterbirth." The placenta is of course the organ that joins the mother and
fetus and permits the provision of oxygen and nutrients to the fetus and the release...
Agammaglobulinemia: Total or near-total absence of gamma globulin, a protein fraction of the blood rich in antibodies, due to certain genetic diseases such as Bruton agammaglobulinemia or to acquired diseases such as HIV/AIDS....
Age by decade
Age by decade: A term designating someone's age by decade. For example, a septuagenarian refers to someone in his or her seventies (age 70 to 79). The prefix in such terms is always from the Latin. For example, the Latin septuageni = seventy.
Denarian: Someone age 10 to 19.
Vicenarian: Someone in ...
Age of mother
Age of mother: See: Maternal age....
Age of father
Age of father: See: Paternal age....
Age-related deafness: See: Presbycusis....
Age-related macular degeneration
Age-related macular degeneration: An eye disease with its onset usually after age 60 that progressively destroys the macula, the central portion of the retina, impairing central vision. Age-related macular degeneration (AMD) rarely causes blindness because only the center of vision is affected. How...
Agency for Toxic Substances and Disease Registry
Agency for Toxic Substances and
Disease Registry: An agency of the U.S. Department of Health and Human Services under the Public Health Service that works with states and
other federal agencies to prevent exposure to hazardous substances from waste
sites. The agency conducts public health assessm...
Agenesis: Lack of development of something. For
example, agenesis of a toe means that toe failed to form. ...
Agenesis of the corpus callosum
Agenesis of the corpus callosum: A congenital abnormality (a birth defect) in which there is partial or complete absence (agenesis) of the corpus callosum, the area of the brain which connects the two cerebral hemispheres (the two halves of the brain).
Agenesis of the corpus callosum can occur as a ...
Agenesis of the gallbladder
Agenesis of the gallbladder: This is a condition in which the gallbladder fails to develop. This happens in approximately one out of every 1,000 people.
Gallbladder agenesis occurs alone in more than two-thirds (70%) of cases. The person with isolated gallbladder agenesis is healthy. No treatment ...
Agenesis, sacral: Failure of formation of all or part of the sacrum (the lowest section of the
Currarino syndrome is a condition characterized by the combination of:
Partial absence of the sacrum (the lowest portion of spine),
Anorectal (anal and rectal) abnormalities, and
Agent Orange: An herbicide and defoliant containing 2,4-D and 2,4,5-T and trace amounts of dioxin. Agent Orange was used as a defoliant in the Vietnam War. There has been concern about Agent Orange as a carcinogen and teratogen (cause cancer and birth defects).
The Institute of Medicine of the Natio...
Agent, anti-infective: Something capable of acting
against infection, by inhibiting the spread of an infectious agent or
by killing the infectious agent outright.
Anti-infective is a general term that encompasses antibacterials,
antibiotics, antifungals, antiprotozoans and antivirals....
Agent, antibiotic: A drug used to treat bacterial infections.
The original definition of an antibiotic was a substance produced by one microorganism that selectively inhibits the growth of another microorganism. However, wholly synthetic antibiotics (usually chemically related to natural antibiotics...