- Discussion:
- cancellous or spongy bone is found at ends of long bones & makes up
greater part of cuboidal bones;
- its chemical composition and ultrastructure are identical to that of
cortical bone;
- cancellous bone is also formed in layers & is, therefore, lamellar bone;
- one difference between cancellous and cortical bone is absence of
haversian systems in former;
- since cancellous bone is in the form of thin plates, its cells are
never very far from surface,and their canalicular systems are
therefor adequate to supply nutrition;
- thus, there is no need for the complicated
haversian systems;
- cancellous bone, like all other bone, is formed by
osteoblasts
that line the surface of small trabeculae;
- cancellous bone of the body presents a tremendously large surface area
that responds readily to physical and metabolic demands of body;
- it is more active metabolically than compact bone & its remodeling
rate is higher;
