Ossification (or osteogenesis ) in bone remodeling is the process of putting new bone material by cells called osteoblasts. This is identical to the formation of bone tissue. There are two processes that result in the formation of normal and healthy bone tissue: Intramembrane hardening is the direct bone accumulation to the primitive connective tissue (mesenchyme), while the endokhondral osification involves cartilage as the precursor. In fracture healing, endocondral osteogenesis is the most common process, for example in long bone fractures treated by Paris plaster, whereas fractures treated with open reduction and internal fixation with metal plates, screws, pins, stems and nails can heal with intramembrane osteogenesis.
Heterotopic ossification is a process that results in the formation of bone tissue that is often unspecific, at extracellular sites. Calcification is often confused with hardening. Calcification is identical to the formation of calcium-based salts and crystals in cells and tissues. This is a process that occurs during hardening, but not otherwise .
The exact mechanism by which bone development is triggered is unclear, but involves growth factors and cytokines in several ways.
Video Ossification
Schedule for human hardening
Maps Ossification
intramembrane osification
Intramembranous hardening forms the skull's flat bones, clavicles and mandibles.
Endokhondral osification
Endotondral ossification is the formation of long bones and other bones. This requires hyaline cartilage precursors. There are two hardening centers for endokhondral hardening.
Primary center
In long bones, bone tissue first appears in the diaphysis (the center of the stem). Chondrocytes breed and form trebeculae. Cartilage is increasingly eroded and replaced by hardened bone, extending in the direction of epiphysis. The perichondrium layer surrounding the cartilage forms the periosteum, which produces osteogenic cells which then proceed to create a collar that surrounds the outer bone and rejuvenates the medullary cavity inside the bone.
The nutrient artery enters through the nutrient foramen from the small hole in the diaphysis. It attacks the main center of hardening, carrying osteogenic cells (osteoblasts outside, osteoclasts on the inside.) The nutrient foramen channel is directed away from the more active end of the bone when one end grows more than the other. When the bone grows at the same level at both ends, the nutrient artery is perpendicular to the bone.
Most of the other bones (eg vertebrae) also have a primary hardening center, and bones are laid in the same way.
Pusat seconds
Secondary centers generally appear in epiphysis. Secondary ossification is occurring mostly after birth (except for the distal femur and proximal tibia occurring during the nine months of fetal development). The epiphyseal arteries and osteogenic cells attack the epiphysis, storing osteoblasts and osteoclasts that erode cartilage and build bones. This occurs on both ends of the long bones but only one end of the number and the ribs.
Evolution
Several hypotheses have been proposed for how bone evolved as a structural element in vertebrates. One hypothesis is that bone develops from a network that evolves into storing minerals. Specifically, calcium-based minerals stored in cartilage and bone are the development of extraction of these calcified cartilages. However, other possibilities include bone tissue developing as an osmotic barrier, or as a protective structure.
See also
- Distrofik calcifications
- Mechanostat, a model depicting hardening and bone loss
- Ossicone, horn-like (or horned) bulge on giraffe heads and related species
- Osteogenesis imperfecta, adolescent bone disease
- Fibrodysplasia ossificans progressiva, a very rare genetic disease that causes fibrous tissue (muscles, tendons, ligaments, etc.) to become hard when damaged
- Primrose syndrome, a rare genetic disease in which cartilage becomes stiff.
References
Source of the article : Wikipedia
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