Dorsal cervical superficial lymph nodes in pigs during prenatal development.

摘要

The aim of the study was to define the topography, number, size and development, and organization level of dorsal cervical superficial lymph nodes (DCSL) of fetal pigs in weeks 5, 8 and 14 of pregnancy. Examinations were carried out on 25 pig fetuses (at days 40, 60 and 97 of gestation) coming from one breeding farm. The material was fixed in 10% formaldehyde solution before carrying out topographical, morphological and histological examinations. Topographical analysis confirmed that DSCL location in fetal life was different than in postnatal life. A slight shift to the caudal-ventral direction was observed during the prenatal development. DSCL became oval at 97 days of gestation, and the growth in size of DSCL was faster between days 60 and 97 than the length of fetus bodies. One lymph node on each side of the body was observed in the majority of subjects. Histological examinations revealed the development of the histological structures from germ cells - in the form of accumulated mesenchymal cells with single transforming lymphoblasts through to the intermediate stage - with more transforming lymphoblasts and lymphatic nodules lying in the centre and in the periphery of lymph node's parenchyma, to the mature fetal lymph nodes - with lymphocytes, and with lymphatic nodules present only in the lymph node's centre..