skeletal Flashcards
specifically, ossification & bone repair proccess
endochondral
long bone ossification
endochondral ossification first step
(1) mesenchymal cells differentiate into chondrocytes
these produce a cartilage model of the future bony skeleton
endochondral ossification second step
(2) blood vessels on the edge of the cartilage model bring osteoblasts (deposits bony collar)
endochondral ossification third step
(3) capillaries penetrate cartilage and despite bone inside model
this forms primary ossification center
endochondral ossification 4th step
(4) cartilage and chondrocytes grow at the end of the bone
medullary cavity expands and remodels
secondary ossification centers develop after birth
endochonrdal ossification 5th step
(5) hyaline cartilage remains on epiphyseal (growth) plate & at joint surface as articular cartilage
intramembranous ossification
flat bone formation
intramembranous ossification 1st step
(1) mesenchymal cells group into clusters
differentiate into osteoblasts
ossification centers form
intramembranous ossification second step
(2) secrete osteoid traps osteoblasts and they become osteocytes
intramembranous ossification third step
(3) trabecular matrix & periosteum form
inramembranous ossification fourth step
(4) compact bone develops superficial to the trabecular bone
crowded blood vessels condense into red bone marrow
bone repair 1st step
(1) broken blood vessels leak blood that clots into a fracture hematoma
bone repair 2nd step
(2) internal & external calluses form (made of cartilage and bone)
bone repair 3rd step
(3) calluses cartilage gradually erodes and is replaced by trabecular bone
this makes hard callus
bone repair fourth step
(4) remodeling occurs to replace immature bone w/ mature bone
