Dictionary

purulent Pertaining to pus. Containing or composed of pus. See also pus.

purpura, Henoch-Schonlein See anaphylactoid purpura.

purpura Hemorrhage (bleeding) into the surface of the skin. The area of skin with purpura is greater than 3 millimeters in diameter. The appearance of an individual area of purpura varies with the duration of the lesions. Early purpura is red and becomes darker, then purple, and brown-yellow as it fades.

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. See also pyrimidine.

purified protein derivative (PPD) The material used in the skin test for exposure to tuberculosis infection.

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…

puncture wound An injury that is caused by a pointed object that pierces or penetrates the skin. Puncture wounds carry a danger of tetanus.

puncture, lumbar See lumbar puncture.

puncture, ear See ear puncture.

punch biopsy A biopsy that is performed by 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 a diagnosis of skin cancer.

pump-oxygenator See heart-lung machine.

pulse rate A measure of the number of pulsations in an artery each minute. Pulse rate is usually taken at the wrist or neck.