Peretiatko O. Structural and functional characteristics of thoracic and cervical lymph nodes of Muscovy ducks in early postnatal ontogenesis.

The thesis paper is dedicated to the investigation of special features of organo-, histo- and cytogenesis of thoracic and cervical lymph node (LN) parenchyma of Muscovy ducks in postnatal ontogenesis. It has been established that lymph node parenchyma of newly-born ducklings has no signs of differentiating into structural and functional areas, or morphological markers of antibody (plasma cells) production function. It has been found that a full complex of morphological features indicative of functional maturity of LN parenchyma is formed during the first three months of postnatal ontogenesis: up to 25-day age - cortical and medullary substance of lymph nodes; up to 60-day age - diffuse structural and functional parenchyma areas; up to 90-day age - lymph nodules. Plasma cells for the first time appear in LN parenchyma of 30-day ducklings, and maximum number of such cells is characteristic of node parenchyma of 240-day ducks. It has been established that definitive structure of LN parenchyma in ducks is characterized by well-defined zoning with concentration of its main functional areas around the central sinus, and by sphere-like space configuration of the best developed cell areas (elements of deep cortex and lymph nodules) with mosaic principle of their location. Separate functional areas of LN parenchyma in ducks are united into several identical by histoarchitectonics compartments, which are composed of deep cortex elements surrounded from all sides by cortical plateau and numerous lymph nodules.