Testa-Riva F, Congiu T, Lantini M S, Puxeddu R, Riva A
Department of Cytomorphology, University of Cagliari, Italy.
Arch Histol Cytol. 1995 Oct;58(4):435-48. doi: 10.1679/aohc.58.435.
The epithelial cells of the human parotid main excretory duct (Stensen) were studied by transmission (TEM) and scanning (SEM) electron microscopy through a variety of procedures that allowed the visualization of their three-dimensional microanatomy. Stensen's duct in humans is lined, in its distal portion, with a pseudostratified epithelium with tall principal cells and smaller basal cells, while the epithelium becomes progressively stratified cylindrically toward the oral stoma. Goblet cells are scattered among the other epithelial cells. The principal cells exhibit, on their lateral surfaces, numerous flattened laminar folds probably involved in transporting processes. A well-developed smooth endoplasmic reticulum intermingled with mitochondria occupies the cellular apices. Some vesicles are recognized on the cytoplasmic surfaces of the apical and lateral plasmalemma when cytoplasmic organelles are removed. All these features are interpreted as being involved in the process of endocytosis. In both TEM and SEM, the principal cells show a relevant number of irregular apical protrusions that may represent a kind of apocrine secretion. Thus, with regard to function, the human Stensen's duct seems to modify the composition of saliva by processes of resorption and secretion, the latter coming from goblet cells as well. The basal cells have a surface microanatomy completely different from that of principal cells. They exhibit, in fact, only sparse microvillosities and smooth areas on their lateral aspect, while their stromal surface is greatly augmented by irregular thin ramified processes. The role of basal cells is also discussed.
通过多种能观察人腮腺主排泄管（斯滕森管）上皮细胞三维微观解剖结构的方法，利用透射电子显微镜（TEM）和扫描电子显微镜（SEM）对其进行了研究。人类的斯滕森管在其远端部分内衬假复层上皮，有高柱状的主细胞和较小的基底细胞，而朝着口腔开口处上皮逐渐变为柱状分层。杯状细胞散在于其他上皮细胞之间。主细胞在其侧面有许多扁平的层状褶皱，可能参与转运过程。发达的滑面内质网与线粒体交织占据细胞顶端。去除细胞质细胞器后，在顶端和侧面质膜的细胞质表面可识别出一些小泡。所有这些特征都被解释为与内吞作用过程有关。在TEM和SEM中，主细胞都显示出相当数量的不规则顶端突起，可能代表一种顶浆分泌。因此，就功能而言，人类的斯滕森管似乎通过重吸收和分泌过程来改变唾液的成分，后者也来自杯状细胞。基底细胞的表面微观解剖结构与主细胞完全不同。事实上，它们在侧面仅显示稀疏的微绒毛和光滑区域，而其基质表面因不规则的细分支突起而大大增加。还讨论了基底细胞的作用。
