initial template for bone formation in the embryonic stage

Hyaline cartilage is used as the model upon which osteoblasts

build bone matrix in a process called ossification

As th

fetus grows the cartilage is digested forming a bone enclosed cavity called the

medulla or

medullary cavity. At birth

only the epiphyseal plate and articular cartilage

have not been converted to bone new cartilage is formed continuously at both

of these locations, making the bone longer

Increase in bone width is appositional growth. To widen the bone,

osteoblasts in the periosteum add bone tissue to the outside the bone shaft

at the same time

osteoclasts remove bone from the medulla

maintaining the thickness of the bone

Once an osteoblast has grown bone around itself and becomes trapped in

bone matrix

inside a lacuna, it differentiates into a mature osteocyte