Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «I»:
Implantation: The act of setting in firmly.
In embryology, implantation refers specifically to the attachment of the fertilized egg to the uterine lining, which occurs approximately 6 or 7 days after conception (fertilization).
In medicine today, many things may be implanted (embedded). There are ...
Implantation, seed: Radiation treatment given by placing radioactive material contained within a small cylindrical shell directly in or near the target, often a tumor....
Implicit memory: Memory characterized by a lack of conscious awareness in the act of recollection. By contrast, explicit memory requires conscious recollection of previous experience.
Implicit memory may survive largely unimpaired at the same time as a person's powers of explicit memory decline wit...
Impotence: A common problem among men characterized by the consistent inability to sustain an erection sufficient for sexual intercourse or the inability to achieve ejaculation, or both. Impotence can vary. It can involve a total inability to achieve an erection or ejaculation, an inconsistent abil...
Imprinting, genomic: The phenomenon of parent-of-origin gene expression. The expression of a gene depends upon the parent who passed on the gene.
For instance, two different disorders - Prader-Willi syndrome and Angelman syndrome -- are due to deletion of the same part of chromosome 15. When the d...
Imprinting, psychological: A remarkable genetic phenomenon that
occurs in animals, and theoretically humans, in the first hours of
life. The newborn creature bonds to the type of animals it meets at
birth, and begins to pattern its behavior after them. In humans, this
is often called bonding and...
Impulsivity: Inclined to act on impulse rather than thought. People who are overly impulsive, seem unable to curb their immediate reactions or think before they act. As a result, they may blurt out answers to questions or inappropriate comments, or run into the street without looking. Their impulsiv...
IMRT: Intensity modulated radiation therapy....
in: Abbreviation for inch....
In situ: In the normal location. An "in situ" tumor
is one that is confined to its site of origin and has not invaded
neighboring tissue or gone elsewhere in the body.
For example, squamous cell carcinoma in situ is an early stage of
skin cancer. It is a tumor that develops from the squamous cel...
In situ hybridization
In situ hybridization: The use of a DNA or RNA probe to
detect the complementary sequence.
In situ hybridization is like all nucleic acid hybridization in being a technique in which single-stranded nucleic acids (DNA or RNA) are permitted to interact so that complexes, or hybrids, are formed by mole...
In situ hybridization, fluorescent
In situ hybridization, fluorescent: An important
molecular cytogenetic method for identifying chromosomes and parts of
chromosomes, deciphering chromosome rearrangements, and locating genes on chromosomes.
"Fluorescent" means emitting light that comes from a reaction within the emitter. "In situ"...
In situ, carcinoma
In situ, carcinoma: Cancer that involves only the place in which it began and has not spread. Carcinoma in situ is an early-stage tumor.
For example, squamous cell carcinoma in situ (Bowen's disease) is an early cancer of the skin. It develops from squamous cells which are flat, scalelike cells in t...
In vitro: Literally in glass, as in a test tube. A test that is performed in vitro is one that is done in glass or plastic vessels in the laboratory.
In vitro is the opposite of in vivo (in a living organism)....
In vitro fertilization
In vitro fertilization: IVF, a laboratory procedure in which sperm are placed with an unfertilized egg in a Petri dish to achieve fertilization. The embryo is then transferred into the uterus to begin a pregnancy or cryopreserved (frozen) for future use. IVF was originally devised to permit women w...