Talk:Paper - lnvolution of tissues in fetal life

The author’s address is:

DR. ARTHUR HERTIG

BOSTON LYING-IN HOSPITAL

221 LONGWOOD AVENUE

BOSTON 15, MASSACHUSETTS

ABSTRACT

There are certain organs and tissues which run a complete life cycle during fetal life. The exocoelomic membrane, for example, is present in the human ovum from the ninth to the thirteenth day, reaches a peak at the twelfth day, then rapidly declines. The yolk sac appears from the twelfth to the seventeenth day, assumes a definite structure, and by the end of the eighth week begins to degenerate until by the time of birth it is only a tiny atrophic structure. The placenta, a highly specialized organ, has a function for ten lunar months, then is discarded at birth. Pathologic aging in the placenta is observed when certain cytological changes pass beyond the normal physiological limits and lead to such phenomena as focal calcification and mural thrombosis of the intervillous space, hematomas, and infarcts. Such diseases as erythroblastosis fetalis lead to a continued immaturity of the placenta because of the continued demand for its function as a blood forming organ. On the other hand, certain toxemias of pregnancy acting through the mechanism of premature senility of the placenta lead to deficiency of the steroid hormone elaborated by this organ.