الفهرس | Only 14 pages are availabe for public view |
Abstract Twenty one male and female albino rats were used in this investigation to study the postnatal development of the liver. They were divided into 7 age groups: newborn, one week, 2 weeks, 3 weeks, 4 weeks, 45 days and adult. Histological sections were prepared and stained with Hex& E and PAS, and examined for the activity of alkaline phosphates and SD enzymes. In the newborn rat, the liver appeared markedly immature. No lobular pattern was detected and hepatocytes lacked organization into plates. Sinusoids were not visible. Hepatocytes appeared vacuolated due to the presence of lipid DROPlets. By one weak, the hepatocytes formed irregular cords of cells radiating from central veins and were separated from each other by wide vascular spaces lined with elongated nuclei which represent the developing liver sinusoids and their lining cells. By two weeks, the lobular pattern became clearly defined and the reportable areas became well-developed with the appearance of bile ductless. In the following stages, the liver showed increase in number and size of lobules. Liver growth during the cipally to both hyperplasia and postnatal period was due to hypertrophy. The presence of mitosis, binucleate cells and compound lobules indicated the role of hyperplasia in the liver development. |