Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «R»:
An array of sites in DNA susceptible to cleavage by diverse restriction enzymes....
Restriction site: A sequence in DNA that can be
recognized and cut by a specific restriction enzyme. ...
Resuscitate: To restore to life. Derived from the Latin resuscitare, to reawaken....
Resuscitation: The procedure of restoring to life, as in cardiopulmonary resuscitation (CPR)....
Resveratrol: An antioxidant present in many plants. Resveratrol is a type of polyphenol called a phytoalexin, a class of compounds produced as part of a plant's defense system against disease. It is produced in the plant in response to an invading fungus, stress, injury, infection, or ultraviolet i...
Retardation, reading: Reading retardation means impaired ability to read. Reading retardation is an impairment that may, for example, reflect mental retardation or cultural deprivation.
Reading retardation is different from dyslexia, a specific reading disability due to a defect in the brain's (hi...
Retic: Short for reticulocyte....
Retic count: Short for reticulocyte count....
Reticulocyte: A young red blood cell that usually remains in the bone marrow with only a few venturing out into the circulating blood. The number of reticulocytes in blood rises when red cell production is unusually vigorous, as after a major bleeding episode or after the bone marrow has been suppre...
Reticulocyte count: The number of reticulocytes (young red blood cells) circulating in blood, usually less than 1% of the total number of the red blood cells. Elevation of the reticulocyte count above 1% (reticulocytosis) is a sign of rapid red blood cell production....
Reticulocytosis: An elevation in the number of reticulocytes (young red blood cells) in blood, a sign of unusually rapid red blood cell production. The number of reticulocytes is normally less than 1% of the total number of the red blood cells. A higher proportion (above 1%) constitutes reticulocyto...
Reticuloendotheliosis, leukemic: See: Hairy cell leukemia....
Retina: The retina is the nerve layer that lines the back
of the eye, senses light, and creates impulses that travel through
the optic nerve to the brain. There is a small area, called the
macula, in the retina that contains special light-sensitive
cells. The macula allows us to see fine details ...
Retina, detached: A retina that separates
from its connection at the back of the eye. The process of retinal detachment is usually due to a tear (a rip) in the retina, often when the vitreous gel pulls loose or separates from its attachment to the retina, most commonly along the outside edge of the...
Retinal: Pertaining to the retina, the extraordinary layer of neurons (nerve cells) that line the back of the eye, which can sense light and create impulses capable of voyaging through the optic nerve to the brain where the impulses are recognized as an image.
For a diagram showing the retina and o...