Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «M»:
Macule: A small localized change in the color of skin that is neither raised (elevated) nor depressed. Macules are never large. They are basically little spots or blemishes in the skin. They are entirely flat and can only be appreciated by visual inspection; they cannot be seen from the side, just f...
Macules: Small circumscribed
changes in the color of skin that are neither raised (elevated) nor depressed. Macules are never large. They are basically little spots or blemishes in the skin. They are entirely flat and can only be appreciated by visual inspection; they cannot be seen from the side.
Maculopathy: Any pathologic condition or disease of the macula, the small spot in the retina where vision is keenest. Also called macular retinopathy....
Maculopathy, cellophane: See: Macular pucker....
Mad deer disease
Mad deer disease: See Chronic wasting disease....
Madelung disease: A disorder characterized by painless symmetrical diffuse deposits of fat beneath the skin of the neck, upper trunk, arms and legs.
The condition is thought to be genetic although its exact mode of inheritance is uncertain; it may be a mitochondrial DNA disease. It frequently appea...
MADH4: A tumor suppressor gene (also known as SMAD4/DPC4) located on chromosome 18 in band 18q21 1. About 15% to 20% of cases of juvenile polyposis are due to germline mutations in MADH4. About 90% of pancreatic carcinomas show homozgous loss (loss of both copies) of MADH4....
Mag sulfate: Informal shortening of magnesium sulfate....
Magendie, foramen of
Magendie, foramen of: An opening from the fourth ventricle, which is one in a system of four communicating cavities called ventricles within the brain that are continuous with the central canal of the spinal cord. The four ventricles consist of the two lateral ventricles, the third ventricle and the...
Maggot: A soft-bodied wormlike larva of a fly that lays its eggs in living or especially in decaying tissues. The living or rotting material furnishes heat for the hatching of the eggs and food for the newly hatched maggots.
Certain blowfly maggots -- notably, those of the blackbottle fly (Phormia ...
Magic bullet: Or, sometimes, silver bullet. 1. The perfect drug to cure a disease with no danger of side effects. The term magic bullet was first used in this sense by the German scientist Paul Ehrlich to describe antibody and, later, the drug salvarsan that he created to treat syphilis.
2. In gen...
Magnesia: Named after a town in present day Turkey where an ore
containing magnesium carbonate was mined. Milk of Magnesia, the laxative, is magnesium
Magnesium: A mineral involved in many processes in the
body including nerve signaling, the building of healthy bones, and normal muscle contraction. About 350 enzymes are known to depend on magnesium.
Magnesium is contained in all unprocessed foods. High concentrations of magnesium are contained in...
Magnesium deficiency: Can occur due to inadequate
intake or impaired intestinal absorption of magnesium. Low magnesium (hypomagnesemia) is
often associated with low calcium (hypocalcemia) and low potassium (hypokalemia).
Deficiency of magnesium causes increased irritability of the nervous system wit...
Magnesium excess: Persons with
impaired kidney function should be especially careful about their magnesium intake because they can accumulate magnesium, a dangerous situation. According to the National Academy of Sciences, the Recommended Dietary Allowances of magnesium are 420 milligrams
per day ...