The histological and histochemical study of the body of axis and lst intervertebral disc in the Korean native cattle fetus was attempted to early developmental process. The experimental animals used in this study were collected from fetus of the Korean native cattle ranging from 50㎜ to 180㎜ in Crown-Rump length(CR-length).
The results were summerized as follows:
1. The ossification centers appeared centrum 1 and centrum 2 of the axis in 110㎜ CR-length fetus of the Korean native cattle. The centrum 2 was formed little earlier than the centrum 1.
2. The histochemical reactions for collagenous fibers in the axis revealed negative in 50㎜ CR-length, mild positive in 90㎜ CR-length, and strong positive in 110㎜ CR-length, respectively.
3. Dense collagenous fibers were observed in the notochord through the centrum 2, and intervertebral disc developed into cuneiform dorsoventrally, It´s contour looks like an annual ring. These fiber bundle arranged lamellar formation.
4. The intervertabral disc of 50㎜ CR-length fetus was composed mainly mesenchymal cells, and these cell showed aggregation in the central portion. The intervertebral disc of 110㎜ CR-length fetus was consisted of pricipally fibroblast, and notochordal sheath formed with two layers in the center.
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