Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «O»:
Open fracture: A fracture in which the bone is sticking through the skin. Also called a compound fracture.
Note that "comminuted fracture" in which the bone is fragmented is distinguished from a "compound fracture."...
Open heart surgery
Open heart surgery: Surgery in which the chest is opened and surgery is performed on the heart. The term "open" refers to the chest, not to the heart itself. The heart may or may not be opened depending on the particular type of surgery....
Open reading frame
Open reading frame: A long sequence of DNA that has no stop codon (no signal to stop reading) and therefore may encode part or all of a protein....
Open wound: An injury that is exposed due to
broken skin. An open wound is at high risk for
Open-angle glaucoma: Glaucoma in which the aqueous (fluid) that flows through the pupil into the anterior (front) chamber of the eye cannot get through a filtration system called the trabecular meshwork into the drainage canals, causing pressure to build up within the eye which can damage the optic ...
Open-label: A term used to describe the situation when both the researcher and the participant in a research study know the treatment the participant is receiving. Open-label is the opposite of double-blind when neither the researcher nor the participant knows what treatment the participant is recei...
Open-label trial: A clinical trial in which researchers and participants know which drug or vaccine is being administered....
Opening, vaginal: The
opening to the muscular canal extending from the cervix to the outside of the body. The word "vagina" is a Latin word meaning "a sheath or scabbard", a scabbard into which one might slide and sheath a sword. The "sword" in the case of the anatomic vagina was the penis. Love an...
Operating room: A facility equipped for
performing surgery. Abbreviated OR....
Operation: Although there are many meanings to the word "operation", in medicine it refers to a surgical procedure.
To put matters more formally, an operation is "an act or series of acts performed upon the body with the hand alone or by means of an instrument", the aim being "to remedy deformity ...
Operation, Blalock-Taussig: A pioneering heart operation named after the American surgeon Alfred Blalock (1899-1964) and the pediatric cardiologist Helen B. Taussig (1898-1986).
Dr. Taussig designed and Dr. Blalock carried out the first "blue-baby" operation to treat a child born with a previously...
Operation, Glenn: See: Glenn shunt....
Operation, Macewen: A surgical
operation for inguinal hernia designed by Sir William
Macewen (1848-1924), a surgeon in Glascow, Scotland who
also described Macewen's sign for the detection of
hydrocephalus and brain abscess. ...
Operon: A set of genes transcribed under the control of an operator gene. More specifically, an operon is a segment of DNA containing adjacent genes including structural genes, an operator gene, and a regulatory gene. An operon is thus a functional unit of transcription and genetic regulation. Opero...
Ophthalmia: Inflammation of the eye. Also known as