Bone is a composite material that consists of mineral and protein. The crystals of mineral are calcium and phosphate that are called hydroxyapatite. The mineral is bound to protein, which is primarily collagen. This composition provides both strength and resilience.
If bone was made only of mineral, it would be more brittle and break easily. In contrast to a structure made only of protein that would be too soft and bend easily. In normal bone, the mineral component provides stiffness and strength. The collagen imparts bone its ability to absorb the energy from an impact without breaking.
Structural Framework of Bone
Bone is designed to be strong yet light enough to move. Bone provides structural support and protection for internal organs. Although bone in this role may seem like a static Halloween skeleton, it is dynamic and constantly changing as old bone is removed and new bone is formed.
Reservoir Function of Bone
Calcium and phosphorus stored in bone are essential for the functioning of all body organs. A constant level of calcium and phosphorus is maintained in the blood to ensure an adequate supply in cells for their function. Regulating hormones interact with bone, intestine, and kidney to mobilize calcium and phosphorous.
If you do not supply these minerals, the skeleton then becomes a resource or reservoir for withdrawal to maintain constant levels. Too many withdrawals can weaken the bone and lead to increased risk of fracture