[Ultrastructure of human hepatocytes in early prenatal ontogenesis].

The structure of hepatic cells was studied in 40 human embryos and fetuses from 4 to 16 weeks of intrauterine development. Depending on the differentiation degree of organells and their amount in the hepatic cell of the embryo and fetus three types of hepatic cells are distinguished: slightly differentiated, transitional and differentiated cells. In the course of early prenatal ontogenesis the amount of slightly differentiated hepatic cells diminishes and the amount of transitional and differentiated forms increases. Glycogen granules are found in the embryo hepatic cells from 7-8 weeks of intrauterine development, and in the course of further embryonic development one can speak of establishment of the protein-forming function of the liver on the basis of increased amount of elements of the endoplasmic network and the presence of numerous ribosomes and polysomes in the cell. The hepatic cells of 14-16 week embryos have well pronounced sinusoid and biliar poles.