Five bands or zones of cells (actually five discs) can be distinguished in a longitudinal section of an epyphiseal disc. The zones portray a sequence of transformations that the chondrocytes of the cartilagineous disc undergo and at the end of the disc they are replaced by bone cells.
Since the cartilage cells undergo subtle transitions from each zone to the next, the boundaries between the zones are not always very precise.
Zones of the epiphyseal disk:
Zone of resting cartilage
Zone of proliferation
Zone of hypertrophic cartilage
Zone of calcified cartilage
Zone of ossification
The first four zones consist of cartilaginous tissue and the last zone of newly produced bone tissue.
Zones of the Epiphyseal disc seen in a longitudinal section of the bone. Staining: HE. Magnification: small.
