人脾的组织发生

FHistogenesis of the Human Spleen

用光镜观察了80例人胎和4例新生儿脾。结果表明，脾发生可分两个阶段。血管网阶段：一直持续到胎12周，脾原基由间充质细胞、网状纤维和小血管构成，在网状纤维间和血管内填充大量的红细胞、少量晚幼红细胞、淋巴细胞与巨噬细胞。此期脾不具备淋巴器官的结构特点。淋巴组织形成阶段：12周后随淋巴细胞的聚集，脾内淋巴细胞逐渐增多，部分细胞密集成团，至14周时红髓、白髓雏形已可分辨。15—16周时动脉周围淋巴鞘与牌小结开始形成，脾索与脾血窦已能区分。18周时脾已具有淋巴器宜的结构特点。从19周一直到出生，红、白髓进一步发育完善。

The spleen of 80 fetuses and 4 neonats were observed with light microscope. The resultsshowed that the development of the spleen could be divided into two stages. The primaryvascular reticulum stage was lasted up to 12th gestational week. The primordium of tilespleen consists of mesenchymal cells.reticular fibers and small vessels. There' are many erythrocytes as well as a few of nomoblasts. lymphocytes and macrophages in the meshes ofthe reticular fibers and in the lumen of the vessels. But. the specific architecture of thespleen, as red and white pule, didn't appear still' The lymphoid tissue forming stage was thelymphocytes gradually increased and crowded together while the lymphoid cells were colonized within the spleen. The primary lymphoid sheeth. the splenic corpuscle. the spleniccord and the splenic sinus could be distinguished at 15-16th week. At 18th week. thespleen possess the tructural characters of the lymphoid organ. The red and white pulp gradually develop perfectly from 19th week to birth.