Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «P»:
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p arm of a chromosome
p arm of a chromosome: The short arm of a
chromosome. The "p" comes from the
French "petit" meaning small. All human chromosomes have 2 arms - the
p (short) arm and the q (long) arm - that are separated from each
other only by a primary constriction, the centromere, the point
at which the chrom...
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p in biochemistry
p in biochemistry: The abbreviation for protein. For example, p53
is a protein (53 kilodaltons in size). ...
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p in population genetics
p in population genetics: The frequency of the more common of two
different alternative (allelic) versions of a gene. (The frequency of less common allele
is q). ...
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P. acnes
P. acnes: See: Propionibacterium acnes....
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P. cepacia
P. cepacia: Pseudomonas cepacia, a bacterium now known as Burkholderia cepacia. See: Burkholderia cepacia....
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p.c.
p.c.: Abbreviation meaning after meals (from the Latin "post cibum", after meals). One of a number of hallowed abbreviations of Latin terms that have traditionally been used in prescriptions.
Some others:
a.c. = before meals (from "ante cibum", before meals)
b.i.d. = twice a day (from "bis in di...
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p.o.
p.o.: Abbreviation meaning by mouth, orally (from the Latin "per os", by mouth). One of a number of hallowed abbreviations of Latin terms that have traditionally been used in prescriptions.
Some others:
a.c. = before meals (from "ante cibum", before meals)
b.i.d. = twice a day (from "bis in die",...
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p.r.n.
p.r.n.: Abbreviation meaning "when necessary" (from the Latin "pro re nata", for an occasion that has arisen, as circumstances require, as needed). One of a number of hallowed abbreviations of Latin terms that have traditionally been used in prescriptions.
Some others:
a.c. = before meals (from "a...
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p53
p53: A tumor suppressor. The designation "p53" stands for "protein 53 kilodaltons" in size.
p53 is a specific protein produced by a gene that functions to suppress the growth of tumors. The p53 gene is the most commonly mutated gene known in human cancer. Like other tumor-suppressor genes, p53 no...
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PA (physician assistant)
PA (physician assistant): A physician assistant (PA) is a mid-level medical practitioner who works under the supervision of a licensed doctor (an MD) or osteopathic physician (a DO).
The physician assistant came about in the 1960s as a response to the need for more clinicians (there was a shortage...
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PA (posteroanterior)
PA (posteroanterior): In anatomy, PA stands for
posteroanterior: from back-to-front. For example, a PA X-ray of the
chest is taken from back-to-front.
PA in this respect is the opposite of AP which stands for
anteroposterior: from front-to-back. ...
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PA X-ray
PA X-ray: An X-ray picture in which
the beams pass from back-to-front (posteroanterior). As opposed to an AP
(anteroposterior) film in which the
rays pass through the body from front-to-back....
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PA-C
PA-C: Physician Assistant - Certified....
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Pacemaker
Pacemaker: A system that
sends electrical impulses to the heart in order to set the
heart rhythm. The pacemaker can be the normal "natural" pacemaker of the heart or it can be an electronic device.
The natural pacemaker of the heart is the sinus node, one of the major elements in the cardiac cond...
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Pacemaker, artificial
Pacemaker, artificial: A device that uses electrical impulses to regulate the heart rhythm or to reproduce that rhythm. An internal pacemaker is one in which the electrodes into the heart, the electronic circuitry and the power supply are implanted (internally) within the body.
Although there are di...
