Bone: the tissue
These images compare woven, immature bone (left) with more mature, adult lamellar bone (right). Woven bone is usually present only temporarily and is replaced by lamellar bone through the process of remodeling. Woven bone is also deposited throughout life during normal bone remodeling as well as in bone repair following a fracture. Woven bone is also Woven bone (l), Mature bone (r), 300x, 300x
Woven, immature bone >
The first bone formed by either intramembranous or endochondral ossification is woven bone. It is characterized as having a large number of osteocytes that appears randomly arranged. Additionally, woven bone has a more basophilic matrix due its lower content of collagen fibers.
Lamellar, mature bone
Mature, lamellar bone is characterized by a reduced number of osteocytes that are more flattened in their lacunae compared with woven bone. The matrix, consisting of circumferentially-arranged lamellae in Haversian systems, is highly eosinophilic due to the large number of collagen fibers present. On the inner and outer surfaces of a bone, lamella are arranged in flat sheets, rather than Haversian systems.
- Haversian systems
Mature, lamellar bone is characterized by a reduced number of osteocytes that are more flattened in their lacunae compared with woven bone. The matrix, consisting of circumferentially-arranged lamellae in Haversian systems, is highly eosinophilic due to the large number of collagen fibers present. On the inner and outer surfaces of a bone, lamella are arranged in flat sheets, rather than Haversian systems.
Osteocytes >
Woven (immature) bone contains a larger number of osteocytes compared with lamellar (mature) bone and the cells are more rounded in their lacunae.
Image source >
Image from the University of Michigan slide collection.
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