Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «P»:
Pavlovian conditioning: The Russian
Petrovich Pavlov (1848-1936) conditioned dogs to respond in what
proved to be a
predictable manner, for example, by first ringing a bell before
feeding them and then
simply ringing the bell upon which stimulus they would begin to
salivate as ...
Pax3: One in a family of Pax genes involved in regulating embryonic development at the level of transcription. The Pax3 gene is on chromosome 2 in band q35. It encodes a DNA-binding transcription factor that is expressed in the early embryo.
Mutation of Pax3 leads to Waardenburg syndrome with a wi...
PCA: Commonly used abbreviation for patient-controlled analgesia. Analgesia simply means relief of pain. PCA is a method by which the patient controls the amount of pain medicine (analgesia) they receive. There are a number of different PCA systems.
In the classic PCA system, the patient receives a...
PCB: See: PCBs....
PCBs: PolyChlorinated Biphenyls, a mixture of up to 209 chlorinated chemicals. Although PCBs are no longer produced in the US where they were once known under the trade name Aroclor, PCBs are still found in the environment. A number of adverse health effects have associated with exposure to PCBs.
PCL (posterior cruciate ligament)
PCL (posterior cruciate
ligament): The knee joint is surrounded by a joint capsule with ligaments strapping the inside and outside of the joint (collateral ligaments) as well as crossing within the joint (cruciate ligaments).
These ligaments provide stability and strength to the knee joint.
PCO: 1. Abbreviation in medical records for "Patient complains of." 2. Abbreviation for polycystic ovary. See also: Polycystic ovarian syndrome....
PCO disease: PCO stands for PolyCystic Ovarian. PCO disease is an hormonal problem that causes women various symptoms including:
Irregular or no periods
Excess hair growth.
All women with PCO have irregular or no menses. Women with PCO do not ...
PCOS: Polycystic ovary syndrome....
PCP: Pneumocystis carinii pneumonia. A parasitic infection of the
lungs that is particularly common and life-threatening in immunosuppressed persons.
Prophylaxis is available to prevent PCP....
PCR (polymerase chain reaction)
PCR (polymerase chain
reaction): PCR (polymerase chain reaction) is a technique in molecular genetics that permits the analysis of any short sequence of DNA (or RNA) even in samples containing only minute quantities of DNA or RNA. PCR is used to reproduce
(amplify) selected sections of DNA or RNA ...
PCT: The abbreviation "PCT" stands for a number of things including porphyria cutanea tarda, literally, the late skin form of porphyria, a genetic photosensitive (light-sensitive) skin disease with onset in adult life with substances called uroporphyrins in the urine due to a deficiency of uroporphy...
PDA: Patent ductus arteriosus....
PDR: Physicians' Desk Reference (please see entry
to Physicians' Desk Reference). PDR less frequently stands for "postdelivery
Pea, jequirity: See: Abrin....