论文部分内容阅读
胸腺是从胚胎第3咽囊所发展的成对器官。胚胎第6周,每侧胸腺始基呈腹面囊状(见图1),以后囊状体向尾侧延长成管状结构,经过上皮的增生,很快成为实体。到胚胎第7周,与第3咽囊的联系断离,两侧始基在中线融合,并下降。到胚胎第8周,最后下降至前纵隔,并附着于心包处。胸腺的残留组织可发现干其正常下降通道的任何部位。进行甲状旁腺探查术,或作甲状腺手术时,偶尔可发现胸腺的残留组织。
The thymus gland is a pair of organs that develop from the third pharyngeal sac of the embryo. At the sixth week of embryonic development, the primordium of each thymus was ventral saccate (see Figure 1). Afterwards, the cystic body extended to a caudal aspect into a tubular structure, which was quickly become an entity after hyperplasia of the epithelium. By the 7th week of the embryo, the contact with the third pharyngeal sac dissected, and both sides of the primordia converged at the midline and fell. By the 8th week of the embryo, it finally fell to the anterior mediastinum and attached to the pericardium. Residual tissue of the thymus can be found anywhere in its normal descending channel. In the case of parathyroid exploration or thyroid surgery, the residual tissue of the thymus can occasionally be found.