This type of osseous tissue lies subjacent to the compact bone, and is made distinct by its spongy structure. It is found at the ends of long bones and in the vertebrae. It has low density and strength but has high surface area that allows room for blood vessels and marrow. The outer surface layer of this tissue contains the red bone marrow where hematopoiesis takes place.
Word origin: spongy < from Latin spongia, from Greek spongiā, from spongos; bone.