A text-book of dental histology and embryology, including laboratory directions . le or complex, depending apparently upon therequirements of protection. In general, the more exposedthe position the thicker is the layer, and the larger andstronger the bundles of fibers of which it is composed. Simple Unattached Periosteum.—Where the periosteum iscovered by a thick layer of muscles which are not attachedto it, as in the thigh, the thinnest and simplest form ofperiosteum is found. An illustration, drawn by Dr. Black,of the periosteum from the femur of a kitten will illustrate itsstructure (Fig.
A text-book of dental histology and embryology, including laboratory directions . le or complex, depending apparently upon therequirements of protection. In general, the more exposedthe position the thicker is the layer, and the larger andstronger the bundles of fibers of which it is composed. Simple Unattached Periosteum.—Where the periosteum iscovered by a thick layer of muscles which are not attachedto it, as in the thigh, the thinnest and simplest form ofperiosteum is found. An illustration, drawn by Dr. Black,of the periosteum from the femur of a kitten will illustrate itsstructure (Fig. 208). The outer layer is composed chiefly of 266 PERIOSTEUM bundles of white fibers, most of which run in a directionparallel with the long axis of the bone. The bundles are com-paratively small and much flattened, so as to be quite rib-bon-like. The inner layer contains a much greater numberof cells lying among extremely delicate fibers. In its outerportion many of the cells are embryonal in character. Incontact with the surface of the bone is a continuous layer of Fig. 208. Non-attached periosteum from the shaft of the femur of the kitten: B, bone; O,layer of osteoblasts. In the central portion of the figure they have been pulled slightlyaway from the bone, displaying the processes to advantage. It will be observed thatthe fibers of the periosteum do not enter the bone, a, inner layer of fine white fibroustissue (osteogenetic layer) showing the nuclei of the fibroblasts and a number ofdeveloping connective-tissue cells, which probably become osteoblasts; c, outer layer,or coarse fibrous layer, in which fusiform fibroblasts are also rendered apparentby double staining with hematoxylin and carmine; d, some remains of the reticulartissue connecting the superimposed tissue with the periosteum, (jj immersion.)(Black.) osteoblasts which are building subperiosteal bone in theyoung animal, processes of their cytoplasm extending intothe canaliculi of the matrix which they have forme
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectteeth, bookyear1912
