人面神经管和面神经的发生

本文对229侧胚胎儿周至出生后1年颞骨组织切片连续观测。结果表明,面神经管由膜性化骨和软骨化骨共同形成。面神经管水平段外侧壁、下壁和迷路段上壁为膜性化骨,膜性化骨顺序有一定规律性;其余部分为软骨化骨。面神经发育随胎龄的增长而递增,出生前渐近高峰;不同部位面神经在面神经管内保持相对恒定的截面积空间比。面神经在面神经管迷路段远侧端所占截面积空间比最大,在茎乳孔处所占截面积空间比最小。本文并提出,胚胎发育后期膜性化骨不全、乳突气化过度是导致面神经管缺损的主要原因。

DEVELOPMENT OF HUMAN FACIAL CANAL AND FACIAL NERVE

The development of the human facial canal and the facial nerve of 229 temporal sides from 11 weeks fetuses to infancies were studied by histological method. The results showed that the facial canal was formed by the membranous ossification and by cartilaginous ossification. The lateral wall, inferior wall of the horizontal segment and the eminous segment, the superior wall of the labyrinthine segment of the facial canal were formed by the membranous ossification. The sequence of the membranous ossification had some regularities. The rest of the facial canal was ossified in the cartilaginous bone. The development of the facial nerve grew in advanced embrylogical age. The length and width diameters of the facial nerve in the facial canal were almost the largest in size before birth. The size of the facial nerve to that of the facial canal is kept in a more or less constant proportion. It was found that the facial norve was largest at the distal portion of the labyrinthine segment of the facial canal and smallest at the stylomastoid foramen.We put forward the conclusion that the disturbances of the membranous ossification in any portion of the facial canal and the anomalies of the pneumatization of the mastoid process were the main causes for the deficiency of the facial canal.