The epiphyseal plate (or epiphysial plate , physis , or growth plate ) is a hyaline cartilage plate in each metaphysical end of long bones. This is part of the long bone where new bone growth occurs; that is, all living bones, with maintenance remodeling throughout the existing bone tissue, but the growth plate is the place where long bones grow longer (add length).
Dishes are found in children and adolescents; in adults, who have stopped growing, the plates are replaced with epiphyseal lines . This replacement is known as epiphyseal closure or fusion growth plate .
Video Epiphyseal plate
Struktur
Development
Endotondral ossification is responsible for early bone development of cartilage in utero and infants and longitudinal growth of long bones in epiphyseal plates. Chondrocytes plates are under a constant division by mitosis. These child cells accumulate facing the epiphysis while the older cells are pushed toward the diaphyisis. When the older chondrocytes degenerate, the osteoblasts form the remaining bones to form new bone. At puberty, elevated levels of estrogen, in women and men, lead to an increase in apoptosis chondrocytes in epiphyseal plates. The depletion of chondrocytes due to apoptosis causes less hardening and slows growth and then stops when the entire cartilage has been replaced by bone, leaving only an epiphyseal scar which then disappears.
Histology
The growth plate has a very specific morphology in having a zonal setting.
A mnemonic to remember the names of the growth zone of the epiphyseal plate is "True People Have Career Choices," standing for: Rest zone, proliferation zone, hypertrophic cartilage zone, calcined cartilage zone, Osification zone. The growth plates are clinically relevant because they are often the main site for infection, metastasis, fractures and endocrine disruption effects.
Maps Epiphyseal plate
Clinical interests
Defects in the development and subsequent cleavage of epiphyseal plates may cause growth disorders. The most common defect is achondroplasia, where there is a defect in cartilage formation. Achondroplasia is the most common cause of dwarfism.
Harris-salter fractures are fractures involving epiphyseal plates and therefore tend to interfere with growth, height or physiological function.
Osgood-Schlatter disease results from stress on the epiphyseal plate in the tibia, causing excessive bone growth and a painful lump in the knee.
Other animals
John Hunter studied the growing chicken. He observed the bones growing at the tip and thus showed the existence of the epiphyseal plate. Hunter is considered the "father of growth plates".
See also
- Human development (biology)
- Fracture of Salter-Harris
References
External links
- The normal bone in GetTheDiagnosis.org, shows the development of epiphyseal plates for different ages and bones.
Source of the article : Wikipedia
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