MICROSCOPIC STRUCTURAL ORGANIZATION OF THE PANCREAS IN THE THIRD TRIMESTER OF INTRACTUAL DEVELOPMENT

Abstract

In the third trimester of fetal development, the software continues to increase signifi cantly in weight. The organ has already undergone the formation of the architecture of a complex alveolar- tubular gland, but the processes of morphofunctional diff erentiation of both the stromal- vascular component and the parenchyma of the pancreas are still ongoing. Particularly active in this period is the process of diff erentiation in the cells of the exocrine and endocrine parts of the parenchyma of the pancreas. We used 30 human objects from 305.0 mm to 500.0 mm of parietal-heel length. On histological preparations of PZ at their staining with hematoxylin and eosin, the already formed particle structure is clearly observed. The capsule is thin and dense, represented by connective tissue. Among its connective tissue structures, in comparison with the early fetal period of embryogenesis, the number of collagen fi bers increases signifi cantly. There are no mesenchymal cells among the stroma cells, but the number of specialized fi broblastic cells is increasing: young and mature fi broblasts with the appearance of single fi brocytes. From the inner surface of the capsule in the thickness of the organ depart trabeculae, similar to the capsule of histological structure. There is a large number of vessels in the connective tissue of the trabeculae. The thickness of the interparticle connective tissue between the already formed particles of the software, compared with the previous term, decreases signifi cantly, and the overall size of the particles themselves increases accordingly. In the interparticle connective tissue are blood and lymphatic vessels of the body with the main duct of the pancreas and interparticle excretory ducts. The main duct of the pancreas is externally surrounded by a massive layer of loose connective tissue, which increases the number of collagen and elastic fi bers and fi broblastic cells. In the thickness of the loose connective tissue of its own plate there are single, already formed, secretory departments of the mucous glands. In fetuses from 28-32 weeks of gestation, the secretion of mucous secretions is already observed and gradually begin to perform their secretory function I-cells. Vessels entwine a dense network of all structural and functional components of the lobe. Theinterparticle ducts branching give rise to rather short intraparticle ducts, which in turn give rise to interacinous. Inlet ducts are a continuation of interacinous ducts. The connection of the pancreatic acini with the insertion ducts gives rise to the entire system of excretory ducts of the exocrine part of the pancreas. The vast majority of the islets of Langerhans are observed in the head of the software, towards the tail, their number and size are gradually decreasing. By the end of the prenatal period of ontogenesis, the pancreas, as an organ of the digestive system, begins to perform its specifi c functions. However, in full its morphofunctional formation does not end and continues it in the postnatal period.