Bones – Structure and properties || Biochemistry & Physiology of Bones

In the Structure and properties of bones, we will discuss the Biochemistry & Physiology of Bones. which in the structure of bones we discuss how the bones made and which kind of matrix or I can say the substances used to form a bone. In the properties of bones, we discuss how bones work and which kind of physiological work they have.

 

Structure and properties of bones

The structure of Bones consists of a dense organic matrix, the strength of which is increased by the calcium salts impregnating it. The compact bone substance is approximately 30% matrix and 70% salt. In the newly forming bone, the percentages are shifted towards a greater representation of the matrix.
Organic bone base – The organic matrix of the bone is 90-95% represented by collagen fibers, and the rest is a homogeneous gelatinous substance called the basic substance. The direction of the collagen fibers generally coincides with the direction of the tensile forces, which increases the ability of the bone to resist stretching.
The main bone substance consists of extracellular fluid and proteoglycans, mainly chondroitin sulfate and hyaluronic acid. The exact function of each is unknown, but together they control the placement of calcium salts in the bone.
Bone salts – Salt crystals are located in the organic matrix of bones and are mainly composed of calcium and phosphates. The formula for most crystalline salts known as hydroxyapatites is Sayu (PO4) 6 (OH) 2.
Each crystal (about 400 angstroms in length, 10-30 angstroms in height, and 100 angstroms in width) is shaped like a long flat plate. The ratio of calcium and phosphate abundance largely depends on the nature of the diet, although usually, the ratio of calcium to phosphates ranges between 1.3-2.0.
In the inorganic substance of the bone – magnesium, sodium, potassium, carbonate ions are also represented, although X-ray diffraction studies did not reveal any crystalline forms formed by them. This suggests that they are more likely to be associated with hydroxyapatite crystals than to form their own crystal structures. The ability to be incorporated into crystalline forms in bone normally exists in many ions foreign to the bone, such as strontium, uranium, plutonium and other transuranic elements, lithium, lead, gold, heavy metals, and finally, 9 of the 14 main radioactive products released during an explosion hydrogen bomb. The placement of radioactive substances in the bone can cause long-term irradiation of the bone tissue and, if large amounts of such substances are deposited, cause osteosarcoma (bone cancer).



In Properties of Bones, The ability of the bone to resist stretching and compression. Collagen fiber in compact bone is composed of periodically repeating sections, each about 640 angstroms long; crystals of hydroxyapatite lie close to these segments, interacting closely with them. This tight bond prevents the bones from separating, as well as the displacement of fibers and crystals relative to each other, which increases bone strength. Also, adjacent areas of collagen fibers are on top of each other, and hydroxyapatite crystals form a kind of clutch around them.
The collagen fibers of the bone, like the collagen fibers of the tendons, are highly resistant to stretching, while the calcium salts impart high resistance to compression. This combination of properties, together with the strong anchoring of collagen fibers and salt crystals to each other, impart extraordinary strength to the bone structure both in compression and in tension.