雌性猪尿道的显微组织结构与空间形态学研究

目的描述正常雌性猪尿道的显微组织结构及其空间构象，为正确理解其控尿机制提供形态学资料。方法取6头正常成年未生育雌性猪的完整尿道，常规固定包埋切片后做Masson’s trichrome染色，观察和描述尿道的显微组织结构和空间构象特点，并运用计算机图像分析系统对尿道各组织成分进行定量分析。结果在全尿道标本的切面上可以清楚地识别尿道横纹肌、平滑肌、致密结缔组织和黏膜等4种基本成分及其特殊的空间构象。横纹肌纤维层呈马蹄形覆盖80％的尿道最外层，在中、远段尿道明显增厚，具有括约肌形态。平滑肌从内到外共有3层，分别是内纵层、中间环形层和外纵层。致密结缔组织分布广泛，并在尿道壁内形成尿道独特空间构象的基本框架和一些特殊结构。结论从尿道独特的空间构象可以看出横纹肌和平滑肌的收缩将使尿道腔缩窄和关闭，致密结缔组织构成尿道括约肌特殊空间构象的基本框架，黏膜层犹如橡胶衬垫具有密封尿道腔隙的作用。

The Microstructural and Spatial Morphological Study Of the Female Pig Urethra

Objective To study the microstructure and the spatial conformation of the normal female pig urethra in order to obtain the morphological information for understanding the sphincter mechanism properly.Methods Step serial histological paraffin sections from proximal,middle and distal parts of the urethra of 6 female pigs,stained with Masson's trichrome,were used to observe and describe the microstructure and the spatial conformation of the urethra and then determine the area percentage of the striated muscle,the smooth muscle,the dense connective tissue,glandular tissue and urethral cavity by computer-assisted image analysis system.Results The urethral anatomy from the step serial histological paraffin sections revealed well defined four layers as striated muscle,smooth muscle,dense connective tissue and mucosa.The striated muscle as the outer layer covered 80% of the whole urethra in horseshoe shape,and it became thicker obviously in the middle and distal parts of urethra.The smooth muscle fibers were arranged in 3 layers as an inner and outer longitudinal layer and a middle circular layer.The dense connective tissue distributed extensively,and it constituted the basic framework of some unique urethral spatial structures in the urethral wall.Conclusion From the unique urethral spatial structure,it can be seen that the contraction of the striated and smooth muscle can shorten and close the urethra.The dense connective tissue is the basic framework of the unique urethral spatial structure,the mucosa functions as a rubber pad to provide a hermetic seal of the lumen.