人胚周皮的超微结构研究

RESEARCH ON ULTRASTRUCTURE OF HUMAN EMBRYO AND FETAL PEREDERM

用光镜和电镜技术对34例(6～20周)人胚手、足和背部周皮进行了观察.根据周皮发育的形态特点,归类为四期:(1)周皮泡前期;周皮表面平坦,细胞扁园,微绒毛稀少,为周皮形成期;(2)周皮泡期;此期周皮相继呈现单泡与复泡,部分区域泡上质膜凹陷呈花瓣状;(3)微绒毛期;周皮出现岛状分布的微绒毛区.细胞表面微绒毛密而长,胞质内散布大量的糖原颗粒.微绒毛区以外的周皮细胞体积增大,似气球状突起,以短蒂和不典型桥粒与中间层细胞相连;(4)周皮脱落退化期;周皮细胞变小细胞器减少,短蒂断裂,细胞脱落.文内还从形态学角度探讨了周皮存在的意义.

The periderm of hands, feet and backs in 36 embryos (6-20 weeks) was studied by light microscopy and electron microscopy. The results show that the periderm falls into four periods; 1. Early stage of periderm bubbles. The surface of the periderm is smooth, cells are oblate and microvilli are few. This is the period of the formation of the periderm. 2. Stage of periderm bubbles. The single bubbles and duplicate bubbles appear one after another with the formation of or ganelles. 3. Stage of microvilli. microvilli areas are dispersed in the form of islands. The microvilli on the surface of cells are long and thick, cells of the periderm beyond microvilli areas break out in ball forms with short handle and cells in middle layer connected together. 4. Stage of degeneration. The cells become smaller, short handles break down and cells come off. The possible significance of the periderm is discussed in this paper.