Ramkrishna V, Tiwari G P
Acta Anat (Basel). 1979;103(3):292-300. doi: 10.1159/000145026.
Non-keratinized, stratified squamous epithelium lined the mucosa of the fore-stomach. The mucosal appendages in the form of ruminal papillae did not develop in the rumen during this study, however, omasal laminae and reticular ribs were evident in groups I and II, respectively. Cytoplasmic accumulations were evident in the middle layer of the epithelium, which is characteristic of this region. The thickness of the epithelium increased constantly in the rumen and reticulum, but in the omasum it remained constant with the increase in the size of the fetus. The corial papillae in the rumen, reticulum and omasum appeared at the 12.7-, 11.5-and 14.6-cm CVR stage, respectively. The muscularis mucosae appeared in the omasum at the 14.6-cm CVR stage in the first-order laminae. The tunica muscularis consisted of spirally arranged muscle fibre bundles. Cross-cut muscle fibre bundles below the tip of the omasal laminae descended downward with the increase in the size of the fetus and continued with the inner circular layer. Acid and alkaline phosphatases and fat could not be observed. The concentration of glycogen in the epithelium was maximum in group III and minimum in group II.
前胃黏膜衬以非角化复层鳞状上皮。在本研究中，瘤胃内未发育出瘤乳头形式的黏膜附属物，然而，在I组和II组中，分别可见瓣胃叶片和网胃肋。上皮中层可见明显的细胞质积聚，这是该区域的特征。瘤胃和网胃上皮厚度持续增加，但瓣胃上皮厚度随胎儿大小增加保持不变。瘤胃、网胃和瓣胃的真皮乳头分别出现在CVR为12.7厘米、11.5厘米和14.6厘米阶段。瓣胃黏膜肌层在CVR为14.6厘米阶段出现在一级叶片中。肌层由螺旋排列的肌纤维束组成。瓣胃叶片尖端下方的横切肌纤维束随胎儿大小增加向下延伸，并与内环层相连。未观察到酸性和碱性磷酸酶及脂肪。上皮中糖原浓度在III组最高，在II组最低。
