胚胎时甲状腺来自内胚层原肠颅端,在胚胎4周时,甲状腺开始形成,当7周时,甲状腺下降至气管第6软骨前,分左右二叶,中间以峡部相连。发生初期的甲状腺,细胞密集成团,成束,逐渐有结缔组织和血管的侵入,在胚胎三个月时,有原始的甲状腺滤泡出现,并有胶体蓄积,以后胶体逐渐增多,在滤泡周围尚有大型的滤泡旁细胞出现。 Thyroid gland embryos from the endodermis when the primitive intestine cranial, 4 weeks in the embryo, the thyroid began to form, when 7 weeks, the thyroid decreased to the trachea 6 cartilage, points about two leaves, the middle of the isthmus connected. Occurred in the early thyroid gland, cells dense into groups, into bundles, and gradually the invasion of connective tissue and blood vessels, three months in the embryo, the original thyroid follicles appear, and there is colloidal accumulation, colloidal gradually increased after the follicles Around the large follicular cells appear.