This document discusses the structure and composition of bones and cartilages. It describes how bones develop through intramembranous or endochondral ossification and are composed of organic and inorganic materials. Bones can be classified as long, short, flat, or irregular. The microscopic anatomy includes the haversian system. Cartilage includes hyaline, elastic, and fibrocartilage. Bones and cartilages are continually remodeled through the actions of osteoblasts and osteoclasts regulated by parathyroid hormone and calcitonin.