Dictionary

pulse The rhythmic dilation of an artery that results from beating of the heart. Pulse is often measured by feeling the arteries of the wrist or neck.

pulse, water-hammer See Corrigan pulse.

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

pump-oxygenator See heart-lung machine.

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.

puncture, ear See ear puncture.

puncture, lumbar See lumbar puncture.

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

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…

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

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.

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.