subs tanti a

(sub-stan's hyah) [L.] Substance. s. adamant i'na [BNA], enamel, the hard substance covering the exposed portion of the teeth it is composed chiefly of calcium phosphate, carbonate, and fluoride, and magnesium phosphate. In structure it is a ma of hexagonal prisms held together by an extremely thin calcified matrix. s. alba [BNA], white substance.* s. cine'rea, gray substance.* s. compac'ta, the compact, non-cancellous portion of bone. s. cortica'lis [BNA], cortex, cortical substance; the [BNA] notes the following: j. c cerebell'i, cerebellum, s. c. glan'dula suprarena'lis, suprarenal gland, i. c. len'tis, crystalline lens, j. c. lymphoglan'duliB, lymph node, s. c. o 'ium, bones, s. c, re'nis, kidney, 5. c. telenceph'ali, cerebrum, s. ebur'nea [B NA], dentine, the ivory forming the ma of the tooth; it is composed of collagen, elastin, calcium phosphate, carbonate, and fluoride, and magnesium phosphate. It is structurele , but contains a large number of fine tubules running in a direction from the pulp cavity to the external surface, in which are found proce es (dentinal fibrils. Tomes 's fibrils) from the odontoblasts, s. femigin'ea, ferruginous substance, an elongated group of pigmented cells, underlying and giving a bluish tint to the locus caerule us in the fioor of the fourth ventricle of the brain, s. gelatinofsa centra'lis [BNA], s. grise a central is, s. gelati no'sa Rolan'di [BNA],. gelatinous substance of Rolando, a light-colored gla y semitranslucent substance, composed chiefly of neuroglia, with, in certain regions, small ganglion cells, which forms the apex of the posterior gray column and, when seen on section, seems to fit over the caput cornu lik^ a cap. s. gris'ea [BNA], s. cinerea, gray substance.* s. gris'ea centra'lis [BNA], s. gelati nos a central is, central gray matter of the spinal cord, a ma of neuroglia surrounding the central canal, s. len'tis [BNA], substance of the crystalline lens; it is divided into i. cortical is, cortex, and nucleus lent is, inner or main substance of the lens. s. meduUa'riS [BNA], medullary substance; the [BNA] notes the following: m.