1 – Zone of calcified cartilage
The limits of this zone cannot be always easily defined in sections.
The chondrocytes in this region (highlighted in light green) are placed at the end of the rows of cells that form the stacks of hypertrophic chondrocytes. Most of them are dying, fragmented or already dead and the sites that they occupied contain remainings of the cells, appear empty or are now hollow.
The walls of cartilage extracellular matrix, which once delimited the spaces formerly occupied by the chondrocytes, become quite thinner (highlighted in turquoise blue).
Calcium salts are progressively deposited in the matrix of these walls.
2 – Zone of ossification
Unlike the cartilage tissue from which this region derives, this zone is vascularized and contains many osteoblasts, besides other bone tissue cells, and bone marrow.
This region is highlighted in pink, and some of its details will be analyzed on the following pages.
