Bone Ossification/osteogenesis Flashcards
What type of ossification only occurs in flat bones?
intramembranous ossification
list the 4 steps involved in intramembranous ossification
- Development of the ossification center
- Calcification
- Formation of trabeculae
- Development of periosteum
What happens in the development of the ossification center stage of intramembranous ossification?
mesenchyme differentiates into
osteoblasts. Osteoblasts secrete osteoid until they are surrounded.
What is calcified during the calcification stage of intramembranous ossification?
extracellular matrix
What dose the extracellular matrix develop into after calcification?
spongy bone/trabeculae
When periosteum is developed by mesenchyme at the periphery of the bone, what replaces the surface layer of spongy bone?
compact bone
Explain endochondral ossification in 6 simple steps
1.Chondroblast develop cartilage model
- Growth of cartilage model by chondroblast cell division
- Development of primary ossification center (diaphysis) bone tissue formation
- Development of medullary cavity (osteoclasts breakdown bone forming cavity)
- Secondary ossification centers develop in epiphysis
- Formation of articular cartilage and epiphyseal plate (hyaline cartilage)
The replacement process of hyaline cartilage with bone tissue is called?
Endochondral ossification
Where does interstitial growth occur in long bones?
At the site of the epiphyseal plate
What are the four zones of interstitial growth (epiphysis down)
- Zone of resting cartilage
- Zone of proliferating cartilage
- Zone of hypertrophic cartilage
- Zone of calcified cartilage
which side of the epiphyseal plate grows?
diaphysis side
What two processes are involved in the remodeling of bone?
Bone resorption by osteoclasts
Bone deposition by osteoblasts
What are the four main factors that affect bone-remodeling?
Minerals (calcium/phosphorus availability)
Vitamins A/C/D
Hormones
Mechanical stress (wolfs law)
