Morphogenesis lymph node of domestic pig

Abstract

The visceral and somatic lymph nodes of a pig of domestic 1-120 day old were examined. Found that the lymph nodes have a common connective tissue capsule and different levels of fusion of individual subunits. In the center of each subunit, the capsule forms invaginations of the capsular trabecula, dividing the parenchyma of each structural unit into «Ʊ»-shaped structures, fused with lateral and lower parts. The number and degree of fusion of subunits is different and depends on the age of the animals and the location of the lymph node. The greatest degree of fusion of individual units of the lymph node was found in the superficial cervical and axillary I ribs. In the mandibular, superficial parotid and superficial inguinal lymph nodes, the segments are clearly contoured already in newborn piglets. Segments are predominantly bean-spherical in shape with a wide base. The fusion of the segments occurs in their central part, and on the surface the gates of the subunits are clearly contoured in the form of numerous depressions. In the visceral lymph nodes, the portal and splenic lymph nodes have the smallest segmentation, and the gastric, tracheobronchial, and iliocolic lymph nodes are the largest. The number of segments varies from two in newborn piglets to five in 120-day-old pigs. The variability of the morphometric parameters of the lymph nodes of a domestic pig is due to a different number of afferent lymphatic vessels, and, accordingly, to different scales of the lymphatic basins. Thus, the lymph nodes of the domestic pig are complexes of subunits fused to varying degrees. Somatic lymph nodes are highly segmented. The degree of consolidation of subunits in the visceral lymph nodes is less pronounced. Linear measurements of organs vary depending on the age of the animals, gradually increasing up to 120 days with a tendency for these indicators to prevail in the somatic lymph nodes. Key words: domestic pig, lymph node, subunit, topography, morphometry