胸腺作为一重要免疫器官的免疫作用是决定于胸腺激素的分泌。有资料表明,胸腺网状上皮细胞的超微结构改变同胸腺体液因子的产生之间有平行关系。本文拟综述由胸腺网状上皮细胞衍变成的特殊结构——胸腺小体的组织学形态及其功能意义。胸腺小体约在胚胎发育第三月的初期出现。光镜下,小体分为实性及囊性两 The immune function of the thymus as an important immune organ is determined by the secretion of thymus hormones. Data show that there is a parallel relationship between the ultrastructural changes of thymic reticular epithelial cells and the production of thymic humoral factors. This article is to review the histological morphology and functional significance of the special structure of thymus reticular epithelium, which is derived from thymus. Thymus is about early in the third month of embryonic development. Light microscope, the body is divided into solid and cystic two