Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «P»:
Pulse, pistol-shot: See: Pulse, water hammer....
Pulse, trip-hammer: See: Pulse, water hammer....
Pulse, water hammer
Pulse, water hammer: A jerky pulse that is full and then collapses because of aortic insufficiency (when blood ejected into the aorta regurgitates back through the aortic valve into the left ventricle). This type of pulse was likened to a water hammer, a Victorian toy consisting of a glass tube fi...
Pulseless disease: Takayasu disease. Called pulseless disease because inflammation of blood vessels (vasculitis) can lead to reduced or absent pulses in the arms or legs. See: Takayasu disease....
Pump-oxygenator: A machine that does the
work both of the heart (pump blood) and the lungs (oxygenate the
blood). Used, for example, in open heart surgery. Blood returning to
the heart is diverted through the machine before returning it to the
arterial circulation. Also called a heart-lung machi...
Punch biopsy: A biopsy performed using a punch, an
instrument for cutting and removing a disk of tissue. For example, a
punch biopsy of the skin may be done to make the diagnosis of a
malignancy. See also: Skin biopsy....
Puncture wound: An injury caused by a pointed object
that pierces or penetrates the skin. Any puncture wound through
tennis shoes (as with a nail) has a high risk of infection, because
the foam in tennis shoes can harbor the bacteria Pseudomonas.
Puncture wounds also carry a danger of tetanus....
Puncture, lumbar:A lumbar puncture or "LP"
procedure whereby spinal fluid is removed from the spinal canal for
the purpose of
diagnostic testing. It is particularly helpful in the diagnosis of
of the central nervous system, especially infections, such as
Pupil: The opening of the iris. The pupil may appear to
open (dilate) and close (constrict) but it is really the iris that is
the prime mover; the pupil is merely the absence of iris. The pupil
determines how much light is let into the eye. Both pupils are
usually of equal size. If they are not,...
Pupil dilation test
Pupil dilation test: An examination that enables an eye
care professional to see more of the retina, the light-sensitive
layer of tissue at the back of the eye. Dilating (widening) the pupil
permits the retina to be examined for signs of disease. To do this,
drops are placed into the eye to dil...
Purine: One of the two classes of bases in DNA and RNA. The
purine bases are guanine (G) and adenine (A). Uric acid, the offending substance in gout,
is a purine end-product....
Purpura: 1. A hemorrhagic area in the skin. The area of bleeding within the skin, by definition, is greater than 3 millimeters in diameter. The appearance of the purpura depends on age of the lesion. Early purpura is red and becomes darker, then purple, and brown-yellow as it fades. Purpura does not...
Purpura, acute thrombocytopenic
Purpura, acute thrombocytopenic: See: Acute thrombocytopenic purpura....
Purpura, allergic: See: Schonlein-Henoch purpura....
Purpura, anaphylactoid: See: Schonlein-Henoch purpura....