ABSTRACT
A single large artery enters the bone marrow cavity via a nutrient foramen and breaks up into several smaller branches which run along the central vein that courses through the axis of the bone marrow mass occupying the medullary cavity of the bone. The sinuses complete the arterial to venous circuit by draining either directly into the central vein or into larger collecting sinuses which abut and drain into the central vein. The extravascular compartment of the bone marrow is the conceptual aggregate of space that is interposed in between the venous sinuses and contains loose fibrous connective tissue and a varied population of cells. Doan devised a historical in vivo avian model in the adult pigeon for the analysis of hemopoiesis in an uncluttered marrow. He pointed out that it was difficult to interpret cellular and architectural relationships in sectioned bone marrow because of the presence of an overabundance of cells.
