Steps of Bone Development: Intramembranous Ossification Part 1 скачать в хорошем качестве

Steps of Bone Development: Intramembranous Ossification Part 1

Welcome to my channel Power of knowledge. In this video You will learn about the process of bone formation, also called development of bone, Osteogenesis or Bone ossification. Bone ossification, or osteogenesis, is the process of bone formation. This process begins between the sixth and seventh weeks of embryonic development and continues until about age twenty-five; although this varies slightly based on the individual. There are two types of bone ossification, intramembranous and endochondral. Each of these processes begins with a mesenchymal tissue precursor, but how it transforms into bone differs. Intramembranous ossification directly converts the mesenchymal tissue to bone and forms the flat bones of the skull, clavicle, and most of the cranial bones. Endochondral ossification begins with mesenchymal tissue transforming into a cartilage intermediate, which is later replaced by bone and forms the remainder of the axial skeleton and the long bones. In this video my focus will be on Intramembranous bone formation and in the next video I will teach you about the process of bone formation (endochondral ossification). Here's a detailed explanation of how intramembranous ossification takes place: Mesenchymal Cell Condensation: The process begins with mesenchymal cells, which are undifferentiated and pluripotent cells derived from mesoderm. These cells condense and cluster together at the site where bone formation will occur. Differentiation into Osteogenic Cells: Within these mesenchymal cell clusters, some cells differentiate into osteogenic cells. Osteogenic cells are committed to becoming osteoblasts, the cells responsible for bone formation. Formation of Osteoid: Osteogenic cells secrete an organic extracellular matrix known as osteoid, which consists of collagen fibers. This osteoid serves as a framework for the future bone. Mineralization: Calcium salts and other minerals begin to deposit within the osteoid. This process is called mineralization, and it transforms the soft osteoid into a harder, mineralized matrix. Osteoblasts: Osteogenic cells that have differentiated into osteoblasts are actively involved in the synthesis and secretion of the osteoid. As the osteoblasts continue to deposit osteoid and promote mineralization, they become surrounded by the newly formed bone matrix. Trabeculae Formation: The mineralized matrix forms a network of thin trabeculae, creating a spongy bone structure. This structure is also called woven bone. Formation of Periosteum: Mesenchymal cells at the periphery of the developing bone condense to form the periosteum, a connective tissue membrane covering the outer surface of the bone. The periosteum contains blood vessels and helps nourish the developing bone. Compact Bone Formation: Over time, as the trabeculae grow and fuse together, they are eventually replaced by more mature lamellar bone, forming compact bone on the surface. Osteoblasts trapped within the bone matrix become osteocytes. Bone Remodeling: The final step involves the ongoing process of bone remodeling, where osteoclasts (bone-resorbing cells) and osteoblasts work together to reshape and strengthen the bone in response to mechanical stresses and other factors. Intramembranous ossification results in the formation of flat bones and certain parts of the skull. It is distinct from endochondral ossification, which is the process responsible for the formation of long bones. #BoneOssification #BoneDevelopment #Osteogenesis