Cellular Growth of the Skeleton
Cartilage
Hyaline Cartilage
The structure of hyaline
cartilage
suits it to its function as a weight-bearing surface in joints.
In all of the synovial joints in the body hyaline cartilage covers the ends of the articulating
bones.
The cells of hyaline cartilage are derived initially from the cellular perichondrium. Cell division in
this covering produces chondroblasts which are able to secrete the components of the matrix.
Chondroblasts retain the ability to divide as they are separated from the perichondrium by the
matrix. While embedded in the matrix chondroblasts divide to form chondrocytes occupying
lacunae within the matrix. Growth of cartilage therefore can occur by addition of cells around the
circumference from the perichondrium, appositional growth, and by cell division within the
matrix, interstitial growth.
Elastic Cartilage
Elastic cartilage is
flexible.
It is found in the epiglottis, pinna of the ear, auditory tube and
eustachian tube. It is organized in a similar way to hyaline cartilage with a perichondrium and
chondroblasts and chondrocytes embedded in a matrix. The major difference is in the matrix
where branched elastin fibres are present in addition to collagen.
Fibrocartilage
In fibrocartilage the
structure is intermediate between that of hyaline cartilage and dense
connective tissue. It is found where bones are bound together such as at the pubic symphysis and
as part of intervertebral discs. There is no recognisable perichondrium. The cells are squeezed
into rows by thick bundles of collagen fibres in the matrix. The collagen is orientated in the
direction of stress. The gel component of the matrix is reduced compared to hyaline cartilage.
Return to MSK Tutorial