. Anatomy, descriptive and applied. Anatomy. Fig. 936.—Ground section through the root of a human pre- molar. D. Dentin. K. Cement corpuscles. O. Osteoblasts, Ep. Remains of Hertwig's epithelial sheath, 200 diameters. -A Interglobular spaces. (Rose.) Fig. 937.—From a ground section through the parts of a dentin, near the pulp, of a human canine tooth which lias been impregnated with pigment. The dental canaliculi are cut across and are joined together by side branches. X 400. The dentinal sheaths, or Netmiann's sheaths, are tubes of markedly resistant dentin sur- rounding and bounding the dent
. Anatomy, descriptive and applied. Anatomy. Fig. 936.—Ground section through the root of a human pre- molar. D. Dentin. K. Cement corpuscles. O. Osteoblasts, Ep. Remains of Hertwig's epithelial sheath, 200 diameters. -A Interglobular spaces. (Rose.) Fig. 937.—From a ground section through the parts of a dentin, near the pulp, of a human canine tooth which lias been impregnated with pigment. The dental canaliculi are cut across and are joined together by side branches. X 400. The dentinal sheaths, or Netmiann's sheaths, are tubes of markedly resistant dentin sur- rounding and bounding the dentinal tnlinlcs. They branch and curve as do the tubules. Tlie matrix, or intertubular dentin, is less dense than that of the sheaths. It fills the spaces between the sheaths, and seems to be composed of lamellae that run parallel to the pulp chamber. Fibrils have been found in the matrix. Scattered in the matrix, and especially near the enamel, are numerous spaces filled with a gelatinous substance; these are the interglobular spaces (spatia interglobulares), representing areas of incomplete calcification. Between the dentin and cementum the spaces are very numerous, but small; these constitute Tomes' granular layer. In a dry tooth a section of dentin often displays a series of lines—the incremental lines oi Salter—which are parallel with the laminae above mentioned. These lines are caused by two facts: (1) The imperfect calcification of the dentinal laminae immediately adjacent to the line. (2) The drying process, which reveals these defects in the calcification. These lines are wide or narrow according to the number of laminae involved, and along their coiu'se, in consequence of the imperfection in the calcifying process, little irregular cavities are left, which are the inter- globular spaces already referred to. They have received their name from the fact that they are smrounded by minute nodules or globules of dentin. Other curved lines may be seen ]>arallel to t
Size: 1446px × 1728px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1913
