11 terms

Endochondral ossification

6 steps
Step 1
chondrocytes in the center of hyaline cartilage enlarge & form struts which begin to calcify. Then the enlarged chondrocytes die, leaving cavities in the cartilage
Step 2
Blood vessels grow around the edges of cartilage; cells in the perichondrium change to osteoblasts, producing a layer of superficial bone around the shaft which will continue to grow & become compact bone (appositional growth)
Step 3
Blood vessels enter the cartilage, bringing osteoblasts, spongy bone develops at the primary ossification center
Step 4
Remodeling creates a marrow cavity, bone replaces cartilage at the metaphyses
Step 5
Capillaries & osteoblasts enter the epiphyses, creating secondary ossification centers
Step 6
Epiphyses fill with spongy bone, cartilage remaining within the joint cavity is the articulation cartilage (Hyaline cartilage only in this phase)
Zone of resting cartilage
small scattered chondrocytes
Zone of proliferation
chondrocytes enlarge & divide
Zone of hypertrophy
chondrocytes are further enlarged
Zone of calcified cartilage
degeneration & death of chondrocytes
Appositional growth
enlarges - width of bone