Bone structure and formation:
Bone is the hardest of the connective tissues. Compact bone (Cortical Bone) and Spongy bone (Spongy Bone) are the two types of osseous tissue or bone tissue that make up bones. The bones are mostly composed of an outer layer of compact bone and an inner layer of spongy bone. Ossification is the process of bone formation. Parts of the skeleton form during the first few weeks after conception. By the end of the eighth week after conception, the skeletal pattern is formed in cartilage and connective tissue membranes and ossification begins.
- Compact bone (Cortical Bone): Due to the strength of compact bone, its main functions is to support the entire body. Compact pact bone also stores calcium. While calcium is being stored in the bone it is also the principle molecule that hardens compact bone.
- Cancellous bone (Spongy Bone): It looks spongy and found in the ends of the long bones, short bones and in between two layers of compact tissue of flat bones. Due to the sponge-like or porous nature of spongy or cancellous bone, spongy bone has a greater surface area compared to compact bone. This allows the bone marrow to develop in the region of the spongy bone. The branching nature of spongy bone also makes it a prime target in diseases such as osteoporosis.