How is histology of bone marrow?

 Bone marrow is the site of hematopoiesis.  Consists of - hematopoietic cells, vascular sinusoids, fibroblasts, fat cells, and macrophages.  No lymphatic channels. • The proportion of fat cells increases with advancing age with corresponding decrease in hematopoietic tissue. Fats cells occupy -  children and adolescents -20-30%  adults - 50%  elderly - 70%