. Kirkes' handbook of physiology . ges are precisely similar to what goes on in the growing shaftof a bone which is increasing in length by the advance of the process of ossifi-cation into the intermediary cartilage between the diaphysis and this case the cartilage cells become flattened and, multiplying by division, OSSIFICATION IN CARTILAGE 49 are grouped into regular columns at right angles to the plane of calcifi-cation while the process of calcification extends into the hyaline matrixbetween them, The embryonic spongy bone, formed as above described, is simply a tem-porary ti
. Kirkes' handbook of physiology . ges are precisely similar to what goes on in the growing shaftof a bone which is increasing in length by the advance of the process of ossifi-cation into the intermediary cartilage between the diaphysis and this case the cartilage cells become flattened and, multiplying by division, OSSIFICATION IN CARTILAGE 49 are grouped into regular columns at right angles to the plane of calcifi-cation while the process of calcification extends into the hyaline matrixbetween them, The embryonic spongy bone, formed as above described, is simply a tem-porary tissue occupying the place of the fetal rod of cartilage; the precedingstages show the successive changes at the center of the shaft. Periostealbone is at the same time deposited in successive layers beneath the perios-teum at the circumference of the shaft, exactly as described in the sectionon ossification in membrane, and thus a casing of periosteal bone is formedaround the embryonic endochondral spongy bone. The embryonic spongy. Fig. 59.—Transverse Section of Femur of a Human Embryo about Eleven Weeks Old. Haversian canal in cross-section; b, in longitudinal section; c, osteoblasts; d, newlyformed osseous substance of a lighter color; e, that of greater age; f, lacunar with their cells; g,a cell still united to an osteoblast. (Frey.) bone is absorbed, through the agency of the osteoclasts, until the trabecularare replaced by one great cavity, the medullary cavity of the shaft. Stage of Formation of Compact Bone. The transformation of spongyperiosteal bone into compact bone is effected in a manner exactly similarto that which has been described in connection with ossification in mem-brane, page 46. The irregularities in the walls of the spongy periostealbone are absorbed by the osteoclasts, while the osteoblasts which linethem are developed in concentric layers, each layer in turn becoming ossifiedtill the comparatively large space in the center is reduced to
Size: 1323px × 1890px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectphysiology, bookyear1
