MICROSCOPIC OF THE STRUCTURAL ORGANIZATION OF PANCREAS AT THE SECOND TRIMESTER OF INTERNAL DEVELOPMENT

Hrymailo N. A, Slobodyan O. M.

MORPHOLOGY

Scentific article

Abstract. The study was performed on 30 objects from 165.0 mm to 300.0 mm of the parietal-heel length using microscopy, morphometry and histological sections of human pancreas. It is established that in the second trimester of intrauterine development in the parenchyma of the pancreas there are active processes of morphofunctional differentiation of the stromal-vascular component and formation the architecture of the organ like complex alveolartubular gland. The exocrine and endocrine parts of the pancreas continue their intensive morphofunctional formation and its microstructure to start of performing self of the specific secretory functions. During this period of development, the stroma and parenchyma of the pancreas is clearly distinguished and the formation of its lobular structure continues. The stroma of the pancreas is represented by a connective tissue capsule and trabeculae, interparticle and intraparticle connective tissue. The parenchyma of the gland is formed by a set of endocrinocytes of the pancreatic islets of the endocrine part and pancreatic acinuses with a system of excretory ducts of the exocrine part of the pancreas. To the end of the 4th and beginning of the 5th months of development, the formation of the pancreatic capsule to be completed. The capsule is a connective tissue structure and is represented by collagen, elastic and single reticular fibers, cells of the fibroblastic, histiocytic and lymphocyte series with a moderate amount of amorphous substance. At the periphery of the pancreas, between the capsule and the area of organ is a thick layer of the connective tissue, what contains the blood vessels and single anastomotic tubules lined with a single layer of cubic epithelium. Into the layers of interparticle connective tissue is a blood and lymphatic vessels of the body, the system of excretory ducts and formed at this stage of development of the pancreatic acinus of the exocrine part and the islets of Langerhans of endocrine part of the pancreas. The duct of the pancreas is lined with a single layer of cylindrical epithelium with a small number of goblet cells and endocrinocytes. From the 16th to the 20th week of fetal development there is significant increase in the number and complication of branches of additional ducts with an increase in the number of pancreatic acini. And from the 22nd week of fetal development, the exocrine part have been performing selfspecific secretory function. At one time in the pancreatic acinuses can appear of the mature pancreatic acinuses and the poorly differentiated. In the lobules, except of exocrinocytes and insulocytes, there is another type of secretory cells acinar-insular (intermediate).

: pancreas, microanatomy, fetus, human

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«Bulletin of problems biology and medicine» Issue 2 (160), 2021 year, 210-215 pages, index UDK 611.37.018-053.15

10.29254/2077-4214-2021-2-160-210-215