Objective To provide the anatomic foundation for dorsoventral X-ray photographs of internal auditory canal. 目的为内听道后前位摄片提供解剖学基础。
In the posterior segment, its dorsoventral axis was the longest, and could be divided into two parts: the dorsal and the ventral parts. 后段的背腹径最长，可分为背侧部和腹侧部，两部分的细胞分界清晰。
The dorsoventral polarity of Drosophila egg is established by means of signaling between the germ line-derived oocyte and the surrounding somatic follicle cells. 果蝇胚胎的发育是由四种系统，分别控制头尾部、前部、后部以及背腹部的形成。
In the posterior segment, its dorsoventral axis was the longest, and could be divided into two parts: the dorsal and the ventral parts.The boundary of the two parts was clear. 后段的背腹径最长，可分为背侧部和腹侧部，两部分的细胞分界清晰。
Conclusion The Pth is a long, narrow and flat structure;its rostrocaudal axis is longer than its dorsoventral axis, and its dorsal edge is smoother than its ventral edge. 结论 皮质加厚区为一吻尾径长于内外径的狭长片状结构， 背侧缘较腹侧缘平滑；
dorsoventral Stretching from the dorsal to the ventral surface; from top to bottom, back to belly. 有背腹性的来自背部到腹面的伸展作业;从顶端到底部,游回腹面。
