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Bone mineral (also called inorganic bone phase, bone salt, or bone apatite) is the inorganic component of bone tissue. It gives bones their compressive strength . Bone mineral is formed predominantly from carbonated hydroxyapatite [ 1 ] [ 2 ] with lower crystallinity.
The components are the mineral crystals of hydroxyapatite, cylindrical collagen molecules, organic molecules such as lipids and proteins, and finally water. [16] The hierarchical structure common to all mineralized tissues is the key to their mechanical performance.
Vivianite crystals are often found inside fossil shells, such as those of bivalves and gastropods, or attached to fossil bone. Vivianite can also appear on the iron coffins or on the corpses of humans as a result of a chemical reaction of the decomposing body with the iron enclosure.
It crystallizes in the hexagonal crystal system. Pure hydroxyapatite powder is white. Naturally occurring apatites can, however, also have brown, yellow, or green colorations, comparable to the discolorations of dental fluorosis. Up to 50% by volume and 70% by weight of human bone is a modified form of hydroxyapatite, known as bone mineral. [7]
Osteoblasts produce an advanced type of bone matrix consisting of dense, irregular crystals of hydroxyapatite, packed around the collagen ropes. [27] This is a strong composite material that allows the skeleton to be shaped mainly as hollow tubes. Reducing the long bones to tubes reduces weight while maintaining strength.
Biomineralization, biologically controlled mineralization, occurs when crystal morphology, growth, composition, and location are completely controlled by the cellular processes of a specific organism. Examples include the shells of invertebrates, such as molluscs and brachiopods. Additionally, the mineralization of collagen provides crucial ...
The canal of the nutrient foramen is directed away from more active end of bone when one end grows more than the other. When bone grows at same rate at both ends, the nutrient artery is perpendicular to the bone. Most other bones (e.g. vertebrae) also have primary ossification centers, and bone is laid down in a similar manner. Secondary centers
It is composed of 270 bones at the time of birth, [2] but later decreases to 206: 80 bones in the axial skeleton and 126 bones in the appendicular skeleton. 172 of 206 bones are part of a pair and the remaining 34 are unpaired. [3] Many small accessory bones, such as sesamoid bones, are not included in this.