Hyaline cartilage is composed of four distinct histologic zones.
The tangential zone, next deepest, contains collagen fibers which are larger, less densely packed, and more randomly oriented and and chondrocytes which are also larger and more clustered. The radial zone is more cellular, with larger chondocytes, which are arranged in columns. The calcified or tidemark zone merges into the subchondral endplate, which itself merges with subchondral cortical bone. Small blood vessels perforate the subchondral endplate and reach the radial zone. More superficial layers derive nutrients from the synovial fluid in which they are bathed.