Pyothorax

(pi-o-tho’ ‘-raks)[Trvov, pus; Ocjpat;, thorax]. An accumulation of pus in the pleural cavity; empyema. Pyoxanthin, Pyoxanthose, (pi-o-zan’-thin, pi-o-zan’ -thos) [ttvov, pus; l-avdog, yellow]. A yellow substance sometimes found in pus, and resulting from the oxidation of pyocyanin. Pyramid having a (pirf-am-id) [Trvpa/uig’] polygonal base and.triangular A solid planes for its sides, which meet at a point called the apex or vertex. P., Anterior, one of the two pyramidal bundles of white matter on either side of the anterior median fi ure of the medulla. P. of the Cerebel um, a conic projection forming the central portion of the inferior vermiform proce . P. of Ferrein, one of the prolongations of the Malpighian pyramid into the cortex of the kidney; it is also known as medullary ray. P., Malpighian, one of the conic ma es composing the medullary substance of the kidney. P., Posterior, one of the two narrow bundles of white matter placed on either side of the posterior median fi ure of the medulla oblong at a. They are continuous with the posterior median columns of the spinal cord. 539