Figure 1
From: Wnt signaling in cartilage development and diseases: lessons from animal studies
Cartilage development and endochondral ossification. (a) The process of endochondral ossification begins from mesenchymal condensation of bipotential osteochondroprogenitors at prospective skeleton sites. These mesenchymal progenitors undergo chondrogenic differentiation, and makes cartilage primodium. (b) The primordial cartilage continues to grow, forming an avascular cartilaginous template surrounded by the perichondrium. Chondrocyte in the center part of the primodium that initiate a growth plate, and undergo hypertrophy. (c) Hypertrophic chondrocytes are calcified and invaded by microvessels forming primary ossification. (d) Vessels invade the epiphyses and form secondary ossification center with osteoblasts and bone marrow. (e) The growth plate contributes to long bone growth. Articular cartilage provides resilience and smooth movement to the joint.
