Bone And Cartilage 2 Flashcards
What are the visible lines surrounding osteon
Cement lines
On outside of the bone is a connective tissue periosteum
Outer layers of bone are organised in LAMELLAE that run around the bone
What are the outer circumferential LAMELLAE
What are osteoprigenitor cells
Located on bone surfaces like periosteum these cells serve as a pool of reserve osteoblasts
What are osteaoblasts
Bone forming cells found on the surface of developing bone
Have plentiful RER and prominent mito
What are osteocytes
Bone cell trapped in bone matrix
What are osteoclasts
Large multi nucleated cells found on surface of bone and responsible for resorption
What is osteoid
The osteoblasts secretion which consists of collagen, gags, proteoglycans, and other organic compounds
LAMELLAE vs woven bone
During normal development bone laid in lamellar collagen fibres
Haphazard form of being laid down is woven bone which is as strong as lamellar and then remodelled to lamellar
What are osteoclasts derived from
Macrophage
A lot of them fuse and form a giant cell
In how ship lacuna
What are osteons
Remodelling causes new osteons to be laid down over old ones
What is interstitial lamellae
LAMELLAE between osteons are the remnants of old osteons
What is intramembranous ossification
Mesenchymal cells diff into osteoblasts and begin syn and secret osteoid at multiple sites
As cells become trapped become osteocytes
At centres of ossifications grow outwards
(Eminences)
What are some examples of bones which safe produced by intramembranous ossification
Flat bones of cranial vault
Mandible
Middle portion of clavicle
What is endochondral ossification
Push bone out from middle
What are some examples of bones produced by endochondral ossification
Most long bones
Base of skull
Medial and lateral ends of the clavicle
