Peretiatko O. Morphogenesis conformities of skeleton blood-making components of cattle fetuses.

Dissertation is devoted to the problem, which is to determine the conformities of prenatal morphogenesis of skeleton blood-making components in fetuses of cattle in connection with enhondral osteohistogenesis processes on organ, tissue and cell levels of structural organization. It is determined that at the beginning of insemination period the blood-making structures of cattle skeleton are focused primarily in major centers of enhondral osteohistogenesis bones, and the degree of their development in accordance with the scale of osteohistogenesis in particular centers. Blood-making marrow in two- months fetuses do not have clearly expressed features of structural and functional differentiations and indications of fat degradation. It was found that cattle fetuses marrow at all stages of morphogenesis are heterogeneous in structural and functional relation - on the first phase (up to 6-months of age) because of its distribution on osteoblast and blood-making forms, on the second phase (up to 9 months of age) as a result of deepening the process of differentiation blood-making marrow with its distribution on diffuse and focal forms with different development stages of morphological characteristics of hematopoietic and osteogenic potential. The fact of the highest degree of development and heterogeneity of blood-making microenvironment in the form of diffuse and focal blood-making marrow and topographic relationship of this form with zones of secondary closed-mashed spongy bone substance cells of enhondral osteohistogenesis is proven. It is determined that cattle fetuses, unlike physiologically mature animals, the maximum potential of universal hematopoiesis with particular blood-making cell development and blood-making microenvironment structures concentrated in the places of skeleton ossification of limbs, the processes of bone-making in which at this stage of development, prevail over the processes of resorption of spongy bone substance.