bone developemtn

Question 1

bones of skull growth process

Answer 1

joined by large fibrous joints in the pre-natal period and early childhoo.

allowd for defermotion dureing passage throug the birth canal as well brain growth

ossifaction spreads outwards towards edges of mebeanous templetye

Question 2

Intramembranous Ossifcaiton process

Answer 2

mesenchyme forms a mebranous template of futre bone

in the centre of template, mesenhyme cells differeniate into osteoblasts to form ossidfcation centre

osteoblast prouce osteoid and Extracellaur matrix

Osteoid becomes minerailised and the osteoblasts mature into osteocytes

bone is initally ‘woven bone’ whcih later matures into 3 layers, centre layer spongy bone called diploe, sandwhciehd b/w 2 outer loyers of compact bone

Question 3

2 forms of ossification

Answer 3

Intramembranous: flat bones, skulls, face, most of scapula, clavicle

endochondral” long, short, irregular 80% of skeleton

Question 4

Endochondral Ossification process

Answer 4

mesenchyme creates template of futre bone

mescenhyme differenites into chondroblasts replacing msenchyme model with hylaine cartliag of futre bone

Periosteum bone collar forms around a dipahsyis of catrilaginoyus bone model.

osteoprogenitor cells differeniate into osteblasts ready to form bone

centre of the cartilagnous model degenrates, oestoblasts as well as blood supply enter forming the primary ossifcation centre which is resposible for boen formation in the diaphysis.

Secondayr ossifcation centre develops at the distal and proixmal ends of bone whihc reuslt in ossidcation of the epiphsyses of the bone

Hylaine cartliage plates divdes the primary and secondary growth centres which allows for bone growth

Question 5

ossifaction starts?

Answer 5

embryonic period (week 8)

complted 18 femalea
21 for males