UL2.H1.4 Cancellous Bone
Cancellous Bone:
- Cancellous bone, sometimes known as trabeculated or spongy bone, is composed of interconnected plates of bone tissue with large spaces between the plates of bone
- The plates of bone contain osteocytes located within lacunae
- The osteocytes in each lacuna are connected to each other, and to the osteoblasts on the surface of the plate, by cytoplasmic processes which run in small channels (canaliculi) in the bone matrix
- These processes connect the osteocytes within the plate of bone to the osteoblasts on the surface
- Blood vessels run adjacent to the surface of the plates of bone
- As in compact bone, these associations provide the route through which nutrients are distributed throughout the bone tissue
- Cancellous bone is typically found in the epiphyses of long bones
- The plates of bone are not randomly organised but are orientated to provide support against the stresses that are applied to the region of bone in which they lie
- Like compact bone, cancellous bone is continually being broken down and replaced as part of the maintenance of the bone tissue
- If different stresses become applied to a region of bone, new replacement bone will align with the lines of stress present at the time
- In life, the spaces between the plates of bone, in cancellous bone, contain bone marrow
Micrograph of Cancellous Bone
