PET-3322 Lecture Notes - Lecture 5: Osteomalacia, Rickets, Prostate Cancer
10 Oct 2017
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Document Summary
6. 5 bone development: ossification (osteogenesis) is the process of bone tissue formation, formation of bony skeleton begins in month 2 of development, postnatal bone growth occurs until early adulthood, bone remodeling and repair are lifelong. Formation of the bony skeleton: bone replaces fibrous membranes and hyaline cartilage of fetal skeleton after week 8, endochondral ossification, bone forms by replacing hyaline cartilage, bones are called cartilage (endochondral) bones, form most of skeleton. Bone collar forms around diaphysis of cartilage model. Central cartilage in diaphysis calcifies, then develops cavities. Periosteal bud invades cavities, leading to formation of spongy bone: bud is made up of blood vessels, nerves, red marrow, osteogenic cells, and osteoclasts. Diaphysis elongates, and medullary cavity forms: secondary ossification centers appear in epiphyses. Epiphyses ossify: hyaline cartilage remains only in epiphyseal plates and articular cartilages. Intramembranous ossification: begins within fibrous connective tissue membranes formed by mesenchymal cells: forms frontal, parietal, occipital, temporal, and clavicle bones, four major steps are involved.
