Skeletal System Bone Development

what is ossification?

process of bone tissue formation

when does ossification occur?

formation of bony skeleton begins in month 2 of development, growth occurs until early adulthood

what are the 2 methods of ossification?

endochondral ossification and intramembranous ossification

what is endochondral ossification?

formation of all bones inferior to base of skull except clavicles

what is required for endochondral ossification to start?

breakdown of hyaline cartilage so it can start at primary ossification center in center of shaft

first step of endochondral ossification

bone collar forms around diaphysis of cartilage model

second step of endochondral ossification

central cartilage in diaphysis calcifies then develops cavities

third step of endochondral ossification

periosteal bud invades cavities, leading to formation of spongy bone

fourth step of endochondral ossification

diaphysis elongates and medullary cavity forms

fifth step of endochondral ossification

epiphyses ossifies