PYRAMID

n. Pi2r'a2m-i2d. Gr., irvpajxis. Lat, pyram is. corpus pyramid ale (3d def.). Fr.,pyramide, coi-ps pyramidal (3d def.). Ger., Pyramide. 1. A solid resting on a plane base of three or more sides, and having as its sides triangular planes which meet at the apex, [a, 48.] 2. A part of the body shaped more or le like a p. 3. A large compact bundle of medullated nerve-fibres situated ventrad in the medulla oblong at a, being the downward continuation of the motorial tract. 4. The petrous portion of the temporal bone. [a, 29.] 5. A pyramidal nerve-cell. [J.] Anterior p's (of the medulla oblong at a). Fr., pyramides bulbaires anterievres. A pair of oblong bodies on the anterior surface of the medulla oblong at a. separated by the anterior median fi ure. [I, 15 (K).] Cortical p's [HenleJ. See P's of Malpighi. Lateral p. See Rextiform BODY. Posterior p. (of the medulla oblong at a). The expanded portion of the funiculus gracilis at the lower angle of the fourth ventricle. [1,15.] P's of Ferrein. Lat., fasciculi tubulosi. The minute cone-like bodies formed by the central tubules of the medullary radii. [J.] P. of Lalouette. See P. of the thyreoid gland. Fof light. Fr., cone de lumiere. See Light SPOT on the membrana tympani.'P.. of Malacarne. The posterior extremity of the middle lobe of the cerebellum. [L, 49 (a. 39).] P's of 3Ialpighi. Lat., com' Malpighii. The pyramidal ma es of the renal cortex, composed of glomeruli, blood-ve els, and convoluted tubules, situated between the medullary radii. They have the base of the p. next the surface of the kidney, and the apex terminating as a renal papilla. ("J, 121; L.] P. of the cerebellum, P. of the inferior vermiform proce . L, ., pyramis cerebelli (sen laminosa, seu vermis). lobus pyriform is. Fr., pyramide du cervelet (ou vermis). Ger., Kleinhirn-Pyramide. A small elevation near the middle of the inferior vermiform proce , between the biventral lobes. [I, 15 (K).] P's of the medulla oblong at a. See P. (3d def.), interior p's, and Posterior p. P. of the spinal cord. Lat., funiculus pyramidal is. See Pyramidal TRACT. P. of the thyreoid gland. A slender conical proce of the gland which extends from the upper part of the isthmus or the adjacent part of the lobes to the hyoid bone, to which it is attached by loose Ibrous ti ue. [C ] P. of the tympanum. Lat., eminent i a pyramidal is (sen papilla.ris). Ger., Pyramidenwulst. A small, lollow bony projection on the inner wall of the tympanum, behind the oval fenestra. The stapedius muscle pa es through a small opening at its apex, [a, 29.] Renal p's. See P's of Malpighi and P's of Ferrein. E, lie; E2, ell; G, go; I, die; I2, in; N, in; N2, tank; [s. 364]