The peculiarities in the structure of microcirculatory bed and venous outflow from the oviduct in Peking duck

The purpose of the study is to clarify the topography, the zones of branching of microcirculatory bed, the distribution patterns and the relationship of both intra-and extra-organ venous vessels involved in oviduct vascularization. The objects of the research are the carcasses of adult birds at 160-180 days of age. For the study of veins, the method of filling through the femoral vein with SKS-65 latex is used, followed by fixation in 4 % aqueous solution of formaldehyde. As a result of the research it was found that all the veins of the bird's oviduct had represented a single hemodynamic system, topographically divided into extra-organ (cranial, middle and caudal protein, cranial and caudal uterine), main (dorsal and ventral oviduct) and intra-organ (cranioventral and caudoventral protein) veins. The veins along their entire length lie on the lateral surface of eponymous arteries, as companion veins. The veins are repeatedly connected with each other by anastomoses running in oblique and transverse directions, surrounding the oviduct from all sides and forming venous plexuses. Longitudinally located dorsal and ventral oviduct veins, having the largest diameter in relation to other oviduct veins, are connected by numerous arched anastomoses located in horizontal and vertical planes. These veins are located on corresponding edges of the oviduct, being the main venous vessels into which venous blood flows from all parts of the organ, ensuring its uniform distribution inside the membranes and progressive movement of venous blood to the left portal renal vein. Structural organization of vascular bed in the oviduct and peculiar distribution of venous vessels provide optimal conditions for the processes of metabolism in various parts of the oviduct while maintaining maximum reliability by means of transorgan blood flow.