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. 24 No.2 (1983)
태아 및 배아 유선의 발달과정에 관한 관찰
An Observation on Development of Mammary Glands in Fetuses and Embryos
- 김우호; 지제근
- Issue Date
- 서울대학교 의과대학
- Seoul J Med, Vol.24 No.2, pp. 185-190
- To evaluate the intra-uterine developmental process
of the mammary gland, a microscopic observation
was made using 38 normal human fetuses and 10
human embryos. Gestational ages were calculated
based on the crown-rump lengths in the fetuses,
and organ development (developmental horizons) in
Following observations were made:
1. The first sign of breast development is recognizable
at the 4th gestational week, and was characterized
by lens-like thickening of the epidermis and
mesenchymal cell condensation. 2. Primordium of mammary gland becomes globoid
by the tith gestational week and lobulated by the
7th week, which corresponds to the primary budding.
3. By the 18th week of gestation secondary buds
grow downward from the primary buds and they
start to branch by the 20th week.
4. The canalization of the lactiferous ducts is
started from the 20th week and completed by the
30th gestational week. The secretory materials are
first seen in the lumina of the glands by the 28th
week of gestation.
S. Lymphocytes start to gather around the duct
from the 20th week and pronounced throughout the
intra-uterine age until term.
6. There is no morphologic difference between
male and female in regard to the breast development
during the intrauterine life.