In a series of studies to investigate the basic features and characteristics of the bone, the present study was made on the structural features of the resting line and reversal line in the bone tissue, using light microscopy, scanning electron microscopy and transmission electron microscopy.
From the result, it was recognized that the zones of the resting line and reversal line were the regions susceptible to dissolution by acid-etching, as compared to the lamellar bone.
Both zones of the resting line and reversal line consist of a small number of fine collagen fibrils and a large number of small rod-like crystals.
The hydroxyapatite crystals were deposited on the surface of the collagen fibril and inside the collagen fibril. In the intercollagen fibril area and non-collagen fibril area, small rod-like crystals were seen deposited densely. These rod-like crystals were seen deposited as a bundle. These bundles of crystals were arranged mainly in two directions.
In the inner structure of the rod-like crystal, the lattice image could not be observed.
The electron diffraction pattern was also not obtained on the crystals so clearly.
Therefore, it was considered that at least the rod-like crystal was not a hydroxyapatite crystal.
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