ABSTRACT
Background: The thymus is one of the primary lymphoid organs other than being the bone marrow. It is responsible for the provision of thymus-processed lymphocytes (T lymphocytes) to the whole body. Aim of the study: To study the microscopic architecture of the cortex and medulla, structure and type of epithelial cells, nature of connective tissue stroma, vasculature of thymus organ, the morphology of Hassall Corpuscle (HC). To study the histometric analysis like estimation of volume and diameter of HC at various gestational age. Method: Total 20 aborted and still born fetuses ranging from 17-39 weeks of gestation were used for the study. After embalming, meticulous dissection, thymus gland was weighed and fixed with formalin. The various histological and histometric parameters were observed. Results: The cortex and medulla were well demarcated by the 17th week. The weight and volume of the thymus were proportionately increased as the fetal age advanced. Early phase had thick mucoid interlobular septae whereas the later phase had thin, reticular interlobular septae. Four different types of HC (SHC, CHC I, CHC II and DHC) in fetus were seen. The presence of solid HC at the periphery of the medulla and degenerating HC at the central core of the medulla tends to postulate the direction of maturation which is from the periphery to the center of the medulla. Conclusion: The findings of the present study is in conformity with studies related to the volume and size of the thymus with respect to gestational ages and histological features related to parenchymal and mesenchymal tissue composition and its various components. However, the present study noted different types of Hassall’s Corpuscles which are reported in the adult thymus and the findings lead to further discussion on the maturation and differentiation of Hassall’s Corpuscles in human fetal thymus.
ABSTRACT
Background and aim: Spleen, a secondary lymphoid organ presents with wide variations in morphology. Size andweight of the spleen varies at different ages and different individuals and in the same individuals under differentconditions. Further, a good knowledge about the morphological variations is very important to the physiciansand surgeons for any pathological conditions of spleen. The aim of the present study was to find out themorphological variations of spleens particularly in the South Indian Population.Materials and methods: A properly embalmed 40 cadaveric spleens were selected for the present study. The studywas carried out in the Department of Anatomy, Rajah Muthiah Medical College,Annamalai University,AnnamalaiNagar, Chidambaram, Cuddalore district, TamilNadu. The data were collected and statistical analysis was done.Results: The present study observed many variations in shapes and sizes of the spleen.Conclusions: In healthy states the spleen is not palpable. However, enlargement of spleen (splenomegaly) thatoccurs in malaria, kalaazar, sarcoidosis and leukaemia it becomes palpable. The morphological variations ofspleen in the present study will be useful to the physicians and surgeons in the diagnosis and treatment ofvarious disorders of spleen.