S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) The Seoul Journal of Medicine The Seoul Journal of Medicine Vol. 26 No.2 (1985)
A Human Embryo of Streeter Age Group XVII
사람배아(Streeter 연령군 XVII)의 1예
- Chi, Je G.; Yang, Hee Jin
- Issue Date
- Seoul J Med, Vol.26 No.2, pp. 139-148
- A human embryo considered to belong to stage XVII of Streeter's developmental
horizon was described. The embryo was surgically removed from a tubal pregnancy.
Although a certain portion of the back side of the embryo was lost during preparation, a
total of 456 serial sections were made through the frontal plane. The ovulation age was
thought to be 42 ±1 days, and the size of the embryo was llmm in crown-rump length.
Characteristic features of the embryo included digital rays in the hand plate, foot plate of the
lower limb bud, inward migration of retinal nuclei, definite pigment granules in the outer layer
of the retina, actively elongating cochlear duct, initiation of semilunar valves, branches of the
second order from stem bronchi, vermiform appendix, follicular lumen of the duodenum,
fused dorsal and ventral pancreas, indifferent gonad and developing suprarenal gland.
Although the embryo derived from a surgical specimen of a tubal pregnancy, there was no
change that could be considered abnormal in nature. Thus the embryo was designated as a