PERICARDIUM

n. Pe2r-i2-ka3rd'i2-u3m. From wepi. around, and teapSia, the heart. Fr., pericarde. Ger., P., Herzhvutel. The somewhat conical membranous sac that contains the heart. It is attached by its base to the central tendon of the diaphragm, and its apex surrounds the ve els arising from the base of the heart. It consists of a dense external fibrous layer, which is continued up on to the great ve els in tubular prolongations that blend above with the cervical fascia. The internal or serous layer covers the heart and the origins of the great ve els, and is reflected upon the inner surface of the outer layer, forming a closed sac which secretes a thin watery fluid. [L, 31, 142, 332.] Cf. EPICARDIDM. P. externum. The fibrous layer of the p. [L.] P. internum. The serous layer of the p. P. parietale. See P. externum. Visceral p. See P. internum. [s. 237]