배아(Streeter 연령군 ⅩⅦ)의 1예

Abstract

A human embryo that is thought to belong to age group XVII of Streeter s developmental horizon is described and reported. This embryo was obtained incidentally from the hysterectomy specimen. It was serially sectioned and was reconstructed with the 643 section slides The length of the embryo was llmm. This embryo was characterized by the formation of pituitary, for' mation of one semicircular duct at the inner ear,thin lens vesicle. marked pigmentation of the retina, complete separation of the right and left atrioventric' 비a r canals , formation of the semilunar valves, incom plete interventricular septum, and the separation of aorta and pulmonary artery. The gonad was undiffe· rentiated and Muellerian duct was not observed From the above findings, we concluded that this embryo belonged to age group XVII of Streeters delopmental horizon.