Age Related Variations in the Architecture of Caprine Haemal Nodes

Abstract

Age related variations in the architecture of caprine haemal nodes were studied in West African dwarf goats aged between 1-24 months. Variations were observed in the thickness of the capsule, the content and organization of the cortical and medulary parenchyma as well as the stroma. In young goats aged between 1-4 months, the capsule was very thin (1-2um) and there was uniformly diffused lymphoid tissue in the cortical and medullary regions. The subcapsular and medullary blood sinuses were either absent or poorly developed in them. The older goats on the other hand, had thicker capsule reaching about 7um in 18-24 months old goats. Lymphoid nodules and blood sinuses were well developed. In the very old goats, features of involution were observed. Irrespective of age, haemal nodes in all animals showed evidence of myelopoiesis and lymphopoiesis. The study suggested that the architecture of haemal nodes so far described by earlier workers might have been influenced by the animal used for the study.