Lymph nodes micromorphology in the head and neck region in rabbits

The aim of the study is to identify the structural features of lymph nodes that determine their functional specialization in the immune system. Objectives: to comprehensively study the micromorphology of the lymph nodes of the head and neck of rabbits using microscopic, statistical and morphometric methods. The objects of the study were carcasses of clinically healthy Californian rabbits aged from one to two years, in the amount of six heads. To identify the lymph nodes, the following research methods were used: conventional and fine dissection. Histological processing was performed (sequential processing of samples in alcohols of increasing concentration, embedding in paraffin, preparing sections, staining). Histological, morphometric and statistical methods were used to study the lymph nodes. The analysis of superficial and deep lymph nodes, including retropharyngeal, parotid and cervical, was performed. The conducted comparative analysis revealed significant intertopographic differences reflecting adaptation to regional functional requirements: the capsule of the retropharyngeal lymph node demonstrates the greatest thickness ((9.29 ± 0.39) μm), the parotid lymph node has the smallest value ((6.16 ± 0.22) μm); the maximum thickness of the septa is in the parotid lymph node ((4.95 ± 0.55) μm), the minimum is in the retropharyngeal ((3.58 ± 0.32) μm); the secondary lymphoid follicle of the superficial cervical lymph node has the largest diameter ((610.62 ± 18.9) μm), the smallest in the retropharyngeal ((353.16 ± 21.85) μm). This gradation correlates with the anatomical position and intensity of the antigen load.