Bone Development & Growth

Intramembranous Bones Forms many flat skull bones, parts of the mandible, and clavicles. Ossification Steps: 1.1 ossification center forms in CT 2.Mesenchymal  Osteoblasts  Osteocytes 3.Blood vessels 4.Spongy bone 5.Compact bone

Intramembranous Bones

Endochondral Bones All bones except some bones of the skull and clavicles. Fetal development-early adulthood Steps 1.Hyaline cartilage cells  Osteoblasts in diaphysis 2.Primary ossification center in diaphysis develops 3.Blood vessels, fibroblasts  Osteoblasts 4.Osteoblasts secrete spongy bone matrix in diaphysis 5.Secondary Ossification in epiphyses forms 6.Epiphyses ossify and remodeling to final form

Endochondrial Bones

 Osteoblasts Osteoclasts 

Growth at the Epiphyseal Plate Growth in width, or thickness, occurs through appositional growth due to deposition of bone matrix by osteoblasts beneath the periosteum.

Homeostasis of Bone Tissue In adult skeletons, bone remodeling is balanced by bone deposit (osteoblasts) and removal (osteoclasts), bone deposit occurs at a greater rate when bone is injured, and bone resorption allows minerals of degraded bone matrix to move into the blood. * Bone resorption is the process by which osteoclasts break down bone and release the minerals, resulting in a transfer of calcium from bone fluid to the blood.

Factors Affecting Bone Development, Growth and Repair Vitamin A, C, and D deficiencies Insufficient Pituitary growth hormone secretions (Dwarfism/Giantism) Thyroid hormone deficiency Sex hormones promote bone formation and stimulate ossification of epiphyseal plates. Physical activity

Group Assignment Each group will be assigned 1 bone function. Instead of reading about each bone function, the lead group for that function will outline the important main ideas then they will share that information with each of the other groups. 1. Support & Protection 2. Body Movement 3. Blood Cell Formation 4. Inorganic Salt Storage