Osteogenesis 1 - Basic Concepts

Osteogenesis 1 - Basic Concepts - sets the ground work that allows the viewer to understand the basic processes that underlie the sequential steps of "building" the skeleton. From conception to ~ 20 years of age,  we grow, and accrue bone mass. From~20 to ~40 we are in balance. From 40 on, we are in a state of decline, losing bone mass. We review the categories of disease,  which may occur an any time.  We point out that bone is a mix of living cells , primarily the osteoctye, and inorganic matrix, and thus has limited possibilities to respond.  In general the response is some variation of normal processes that are operant in growth and development. These processes will be shown in subsequent videos.  Consider first the cells involved:  all  are derived from the mesenchymal stem cell and become cells that first produce, and then maintain the structural elements (fat, fibrous tissue, cartilage, bone, muscle), and then cells that produce vessels (endothelial), that control blood flow (glomerular), and that populate the areas around the vessels (hematopoietic, immunogenic, or perithelial (a stem cell pool). Detailed structure and function of osteoblasts, osteoclasts, and osteocytes is followed by their roles in the three types of bone formation - membranous or woven, enchondral, and lamellar. This information sets the stage as the two videos, Osteogenesis 3 and 5 show the natural history of the skeleton.