VETERINARY SCIENCE AND ANIMAL HUSBANDRY TOPOGRAPHY AND MORPHOLOGY OF THORACOCERVICAL LYMPH NODES OF DOMESTIC GEESE

Abstract

It is established that in geese, are constantly registered only cervicothoracic lymph nodes. The cervicothoracic lymph nodes of geese are local accumulations of lymphoid tissue in the wall of the lymphatic vessels, which are taking away lymph from the head and neck. The cervicothoracic lymph nodes of geese are not the same shape, most of them have a conical shape. Parameters of absolute, relative weights, and size of the cervicothoracic lymph nodes of geese depend on the weight and sizes of their body. The cervicothoracic lymph nodes of geese are formed by a connective tissue stroma, parenchyma, and sinus. Connective tissue stroma is represented by a capsule, which is a continuation of the adventitia and media of lymphatic vessels and trabeculae. Connective tissue stroma is formed by loose fibrous connective tissue, which has blood vessels and myocytes. Sinus is a continuation of the lymphatic vessel lumen and its wall – a continuation of its intima. The area, occupied by a connective tissue stroma, parenchyma, and sinus in the nodes of investigated birds, varies. The largest area occupies the parenchyma of the cervicothoracic lymph nodes, which like the parenchyma of lymph nodes in mammals, is formed by lymphoid tissue. In the parenchyma, there is unclearly allocated the cortical and cerebral substances. The cortical substance is located on the periphery and the cerebral substance – around the sinus. The area of the cortical substance dominates over a cerebral substance. The cortical substance is formed by the diffuse lymphoid tissue and lymphoid nodules (mainly secondary), and the cerebral substance – only by the diffuse lymphoid tissue. Lymphoid nodules are spherical in shape, surrounded by delicate shells, and depending on the diameter, is divided into three groups: large, medium, and small. The basis of the lymphoid tissues in the parenchyma is reticular tissues, which consists of reticular fibers. The architectonics of its fibers varies in the different components of the lymphoid tissue. They are placed tightly, intertwined, and form the confined units of various shapes and small sizes. The cellular composition of the parenchyma of the cervicothoracic lymph nodes of geese is extremely diverse. It is reticulocytes, lymphocytes, immunoblasts, macrophages, monocytes, plasma cells, mast cells, and myoid cells. The content of these cells is not the same. The presence of lymphocytes, immunoblasts, macrophages, and plasma cells in the parenchyma of the cervicothoracic lymph nodes of geese convinces in their functioning as peripheral organs of immunogenesis

Keywords

• geese
• cervicothoracic lymph nodes
• connective tissue stroma
• parenchyma
• central sinus
• cortical substance
• medullary substance
• lymphoid follicles
• lymphoid cells