The perichondrium (from
Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
and ) is a layer of
dense irregular connective tissue
Dense irregular connective tissue has fibers that are not arranged in parallel bundles as in dense regular connective tissue.
Dense irregular connective tissue has less ground substance than loose connective tissue. Fibroblasts are the predomin ...
that surrounds the
cartilage
Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...
of developing bone. It consists of two separate layers: an outer fibrous layer and inner
chondrogenic layer. The fibrous layer contains
fibroblasts
A fibroblast is a type of biological cell typically with a spindle shape that synthesizes the extracellular matrix and collagen, produces the structural framework ( stroma) for animal tissues, and plays a critical role in wound healing. Fibrobla ...
, which produce
collagenous fibres. The chondrogenic layer remains undifferentiated and can form
chondroblasts
Chondroblasts, or perichondrial cells, is the name given to mesenchymal progenitor cells in situ which, from endochondral ossification, will form chondrocytes in the growing cartilage matrix. Another name for them is subchondral cortico-spongio ...
. Perichondrium can be found around the perimeter of
elastic cartilage and
hyaline cartilage
Hyaline cartilage is the glass-like (hyaline) and translucent cartilage found on many joint surfaces. It is also most commonly found in the ribs, nose, larynx, and trachea. Hyaline cartilage is pearl-gray in color, with a firm consistency and has ...
.
Perichondrium is a type of irregular collagenous ordinary connective tissue, and also functions in the growth and repair of cartilage. Perichondrium contains
type I collagen
Type I collagen is the most abundant collagen of the human body, consisting of around 90% of the body's total collagen in vertebrates. Due to this, it is also the most abundant protein type found in all vertebrates. Type I forms large, eosinop ...
and
type XII collagen.
References
External links
*
Iowa Histology Index 4/iv-05' - "Slide 12, Developing Bone (H&E). Examine cartilage (right) and its perichondrium (arrows)."
*
Skeletal system
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