Final answer:
The development of bones involves osteoblasts forming new bone, osteocytes maintaining bone tissue, and osteoclasts breaking down bone. Cartilage serves as a template during bone development in a process called ossification, with bone growth continuing until about age 25. Bone growth, repair, and remodeling are essential ongoing processes throughout life.
Step-by-step explanation:
The development of bones, or ossification, involves several key cell types and processes. Osteoblasts are the cells responsible for new bone formation. These cells secrete the organic and inorganic components of the bone matrix, which includes collagen fibers. As osteoblasts become trapped in their secretions, they differentiate into osteocytes, which are mature bone cells that maintain bone tissue. On the other end of the spectrum, osteoclasts are involved in the breakdown of bone tissue, a process necessary for the release of calcium into the bloodstream and bone remodeling. During the development of bones, cartilage plays a crucial role as a template in which most bones develop. Two types of ossification are involved in bone development: intramembranous ossification, which is the transformation of fibrous membranes into bone, and endochondral ossification, which is the transformation of hyaline cartilage into bone. Growth of bones occurs via the division of chondrocytes in cartilage, especially within the epiphyseal plates of long bones, and bone lengthening continues until about age 25. Bone growth, bone repair, and bone remodeling are ongoing processes. Bone growth occurs during childhood and adolescence, bone repair follows injury to a bone, and bone remodeling is the lifelong process where the bone is continually resorbed and formed in response to physical stress and changes in calcium levels in the blood.