"Abstract"
The rat can be considered as an ideal experimental model for
studying the development and congenital malformation in human,
because of the similarity of structures in human and rat during the
embryonic period of development. The aim of this work is to study the
normal prenatal development of the rat liver from the 12th day to the 20th
day of gestation.
Twenty five pregnant female rats were used in this study. The
embryos and fetuses were taken out from the uterine horns at days 12,
14,16,18 and 20 of gestation. They were fixed in Bouin's solution,
dehydrated in alcohol and embedded in paraffin sections. Sections 5-
7}.tin thick were cut in longitudinal and transverse planes. Serial sections
were stained with hematoxylin-eosin and iron hematoxylin.
At 12111 day of gestation, the hepatic bud migrated upward and
proliferated to form liver cell mass with blood sinusoids in between
hepatocytes. At 14111 day of gestation, the liver cell mass divided into two
lobes which contained the transverse portal sinus. The blood sinusoids
contained nucleated erythrocytes. At 16 day of gestation, the two lobes |
