Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «M»:
Methylenedioxymethamphetamine: 3-4 methylenedioxymethamphetamine (MDMA), best known on the street as "Ecstacy." An illicit drug, considered a recreational or party drug. It acts as both a stimulant and a hallucinogen. Ecstasy achieves its high by preventing the brain from reabsorbing the chemical se...
Methylmalonicaciduria: An inherited metabolic (biochemical) disease that causes young children to become mentally retarded.
The defect in some (but not all) of these children has to do with an inability to use the vitamin B12 they ingest. If these children are given very large supplements of vitami...
Methylmercury: An organic form of mercury that is highly toxic and is the main culprit in mercury poisoning. Methylmercury is easily absorbed into the living tissue of aquatic organisms, is not easily eliminated, and therefore accumulates in fish that are predators. The degree to which mercury is tr...
Metrorrhagia: Uterine bleeding at irregular intervals, particularly between the expected menstrual periods. Metrorrhagia may be a sign of an underlying disorder, such as hormone imbalance, endometriosis, uterine fibroids or, rarely, cancer of the uterus. Metrorrhagia may cause significant anemia. Se...
Meuse fever: Named for the Meuse River area, one of
the great battlegrounds of World War I. Also known as trench fever.
Meuse or trench fever is a disease borne by body lice that
was first recognized in the trenches of World War I, when it is
estimated to have affected more than a million peopl...
mg: Abbreviation for milligram, a unit of measurement of mass in the metric system equal to a thousandth of a gram. A gram is equal to the mass of one milliliter, one thousandth of a liter, of water at 4 degrees C.
MG (in capital letters) is the abbreviation for the disease myasthenia gravis....
MG (myasthenia gravis)
MG myasthenia gravis (MG): An autoimmune neuromuscular
disorder characterized by fatigue and exhaustion of muscles. It is
caused by a mistaken immune response to the nicotinic acetylcholine receptors (AChR), which are found in junctions between muscles and the
nervous system. The body produces
mGy: Abbreviation for milligray....
MHC: Major histocompatibility complex....
MI: Commonly used abbreviation for myocardial infarction, otherwise known as a heart attack.
The term "myocardial infarction" focuses on the heart muscle, which is called the myocardium,and the changes that occur in it due to the sudden deprivation of circulating blood. This is usually caused by art...
Miasma: A poisonous vapor or mist believed to be made up of particles from decomposing material that could cause disease and could be identified by its foul smell.
The miasma theory of disease originated in the Middle Ages and persisted for centuries. During the Great Plague of 1665, doctors wore ...
Miasmic: Pertaining to a miasma, a poisonous vapor or mist that was once widely believed to be made up of particles from decomposing material which could cause disease and which could be identified by its foul smell. See: Miasma....
MIC-1: Macrophage inhibitory cytokine 1. A divergent member of the transforming growth factor beta superfamily. MIC-1 is produced in the placenta. There are detectable levels of MIC-1 in the blood of the mother during pregnancy. Low levels of MIC-1 in maternal serum are predictive for an elevated ri...
Michael Stuart Brown
Michael Stuart Brown: See: Brown, Michael Stuart....
Micro-: Prefix derived from the Greek "mikros"
meaning small. Examples of the many biomedical terms containing "micro-" include the following:
microcystic (as in microcystic corneal dystrophy),