endochondral bone

endochondral

• 軟骨内性骨/軟骨性骨

WordNet

1. remove the bones from; "bone the turkey before roasting it" (同)debone
2. the porous calcified substance from which bones are made (同)osseous_tissue
3. consisting of or made up of bone; "a bony substance"; "the bony framework of the body"
4. a shade of white the color of bleached bones (同)ivory, pearl, off-white
5. rigid connective tissue that makes up the skeleton of vertebrates (同)os
6. having bones as specified; "his lanky long-boned body"
7. having had the bones removed; "a boneless rib roast"; "a boned (or deboned) fish" (同)deboned
8. a percussion instrument consisting of a pair of hollow pieces of wood or bone (usually held between the thumb and fingers) that are made to click together (as by Spanish dancers) in rhythm with the dance (同)castanets, clappers, finger cymbals

PrepTutorEJDIC

1. 〈C〉骨 / 〈U〉骨を作っている物質,骨質 / 《複数形で》骨格;死骸(がい) / 〈魚など〉‘の'骨を取る
2. (魚など)骨を取り除いた / (衣服が)(コルセットなどで)骨で張りをつけた[ような]

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/04/30 01:59:48」(JST)

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Endochondral ossification
Light micrograph of epiphyseal plate showing endochondral ossification: healthy chondrocytes (top) become degenerating ones (bottom), characteristically displaying a calcified extracellular matrix.
Anatomical terminology [edit on Wikidata]

Endochondral ossification is one of the two essential processes during fetal development of the mammalian skeletal system by which bone tissue is created. Unlike intramembranous ossification, which is the other process by which bone tissue is created, cartilage is present during endochondral ossification. Endochondral ossification is also an essential process during the rudimentary formation of long bones, the growth of the length of long bones, and the natural healing of bone fractures.

Growth of the cartilage model

The cartilage model will grow in length by continuous cell division of chondrocytes, which is accompanied by further secretion of extracellular matrix. This is called interstitial growth. The process of appositional growth occurs when the cartilage model also grows in thickness due to the addition of more extracellular matrix on the peripheral cartilage surface, which is accompanied by new chondroblasts that develop from the perichondrium.

Primary center of ossification

The first site of ossification occurs in the primary center of ossification, which is in the middle of diaphysis (shaft). Then:

1. Formation of periosteum

   The perichondrium becomes the periosteum. The periosteum contains a layer of undifferentiated cells (osteoprogenitor cells) which later become osteoblasts.

2. Formation of bone collar

   The osteoblasts secrete osteoid against the shaft of the cartilage model (Appositional Growth). This serves as support for the new bone.

3. Calcification of matrix

   Chondrocytes in the primary center of ossification begin to grow (hypertrophy). They stop secreting collagen and other proteoglycans and begin secreting alkaline phosphatase, an enzyme essential for mineral deposition. Then calcification of the matrix occurs and osteoprogenitor cells that entered the cavity via the periosteal bud, use the calcified matrix as a scaffold and begin to secrete osteoid, which forms the bone trabecula. Osteoclasts, formed from macrophages, break down spongy bone to form the medullary (bone marrow) cavity.

Secondary center of ossification

About the time of birth in mammals, a secondary ossification center appears in each end (epiphysis) of long bones. Periosteal buds carry mesenchyme and blood vessels in and the process is similar to that occurring in a primary ossification center. The cartilage between the primary and secondary ossification centers is called the epiphyseal plate, and it continues to form new cartilage, which is replaced by bone, a process that results in an increase in length of the bone. Growth continues until the individual is about 20 years old or until the cartilage in the plate is replaced by bone. The point of union of the primary and secondary ossification centers is called the epiphyseal line.

Appositional bone growth

The growth in diameter of bones around the diaphysis occurs by deposition of bone beneath the periosteum. Osteoclasts in the interior cavity continue to degrade bone until its ultimate thickness is achieved, at which point the rate of formation on the outside and degradation from the inside is constant.

Histology

Drawing of part of a longitudinal section of the developing femur of a rabbit. a. Flattened cartilage cells. b. Enlarged cartilage cells. c, d. Newly formed bone. e. Osteoblasts. f. Giant cells or osteoclasts. g, h. Shrunken cartilage cells. (From “Atlas of Histology,” Klein and Noble Smith.)

Masson Goldner trichrome stain of growth plate in a rabbit tibia.

During endochondral ossification, five distinct zones can be seen at the light-microscope level.

Name	Definition
Zone of resting cartilage	This zone contains normal, resting hyaline cartilage.
Zone of proliferation / cell columns	In this zone, chondrocytes undergo rapid mitosis, forming distinctive looking stacks.
Zone of maturation / hypertrophy	In this zone, the chondrocytes undergo hypertrophy (become enlarged). Chondrocytes contain large amounts of glycogen and begin to secrete alkaline phosphatase.
Zone of calcification	In this zone, chondrocytes are either dying or dead, leaving cavities that will later become invaded by bone-forming cells. Chondrocytes here die when they can no longer receive nutrients or eliminate wastes via diffusion. This is because the calcified matrix is much less hydrated than hyaline cartilage.
Zone of ossification	Osteoprogenitor cells invade the area and differentiate into osteoblasts, which elaborate matrix that becomes calcified on the surface of calcified cartilage. This is followed by resorption of the calcified cartilage/calcified bone complex.

Section of fetal bone of cat. ir. Irruption of the subperiosteal tissue. p. Fibrous layer of the periosteum. o. Layer of osteoblasts. im. Subperiosteal bony deposit. (From Quain’s “Anatomy,” E. A. Schäfer.)

Fracture healing

During fracture healing, cartilage is often formed and is called callus. This cartilage ultimately develops into new bone tissue through the process of endochondral ossification.

References

See also

• Intramembranous ossification
• Ossification

UpToDate Contents

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• 1. 骨格の正常な発達および骨形成ならびに骨吸収の調節 normal skeletal development and regulation of bone formation and resorption
• 2. 骨折のマネージメントの一般原則：骨治癒および骨折について general principles of fracture management bone healing and fracture description
• 3. 骨パジェット病の臨床症状および診断 clinical manifestations and diagnosis of paget disease of bone
• 4. Overview of the epidemiology, clinical presentation, diagnosis, and management of adult patients with bone metastasis
• 5. 小児癌患者の骨に関する問題 bone problems in childhood cancer patients

English Journal

• mTORC1 regulates PTHrP to coordinate chondrocyte growth, proliferation and differentiation.

• Yan B1, Zhang Z1, Jin D1, Cai C2, Jia C3, Liu W3, Wang T3, Li S1, Zhang H1, Huang B1, Lai P1,3, Wang H1,3, Liu A3, Zeng C1, Cai D1, Jiang Y4, Bai X1,3.
• Nature communications.Nat Commun.2016 Apr 4;7:11151. doi: 10.1038/ncomms11151.
• Precise coordination of cell growth, proliferation and differentiation is essential for the development of multicellular organisms. Here, we report that although the mechanistic target of rapamycin complex 1 (mTORC1) activity is required for chondrocyte growth and proliferation, its inactivation is
• PMID 27039827

• [Genome-wide association study for Osteoporosis].

• Mori S1.
• Clinical calcium.Clin Calcium.2016 Apr;26(4):537-43. doi: CliCa1604537543.
• Numerous studies on genetic risks for osteoporosis have been performed to date, mainly using genome-wide association studies(GWAS)for assessing bone mineral density(BMD)as a quantitative trait, and recent large-scale meta-analyses of GWAS have identified a number of single nucleotide polymorphisms(S
• PMID 27013623

• BMP signalling in skeletal development, disease and repair.

• Salazar VS1, Gamer LW1, Rosen V1.
• Nature reviews. Endocrinology.Nat Rev Endocrinol.2016 Apr;12(4):203-21. doi: 10.1038/nrendo.2016.12. Epub 2016 Feb 19.
• Since the identification in 1988 of bone morphogenetic protein 2 (BMP2) as a potent inducer of bone and cartilage formation, BMP superfamily signalling has become one of the most heavily investigated topics in vertebrate skeletal biology. Whereas a large part of this research has focused on the role
• PMID 26893264

Japanese Journal

• Regulation of mouse chondrocyte differentiation by CCAAT/enhancer-binding proteins

• , , , , , , ,
• Biomedical Research 36(1), 21-29, 2015
• … CCAAT/enhancer-binding protein (C/EBP) β regulates chondrocyte differentiaion and proliferation during endochondral ossification. …
• NAID 130004903876

• Bone Morphogenetic Proteins: Their History and Characteristics

• Asahina Izumi
• Journal of Hard Tissue Biology 23(3), 283-286, 2014-07-10
• … Bone tissue engineering is expected to be utilized clinically as a patient friendly strategy instead of autogenous bone grafts, and bone morphogenetic protein (BMP) is applying for bone regeneration. … BMPs have critical functions in embryonic development and tissue generation, and BMPs induce bone formation in mammals though its primary functions are different. …
• NAID 120005477009

• ナトリウム利尿ペプチドによる骨・軟骨制御機構

• 八十田 明宏
• 内分泌・糖尿病・代謝内科 39(1), 92-98, 2014-07
• NAID 40020175985

Related Links

• Bone Development: Endochondral Ossification Tutorial ...

- Define and apply the following terms to bone growth and development: lamellae, lacunae, canuliculi, Haversian systems, compact bone, cancellous bone, trabeculae - Identify what type of bones develop from endochondral ...

• Endochondral bone | definition of endochondral bone by ...

en·do·chon·dral bone a bone that develops on and within a cartilage template; the template is entirely destroyed by calcification and subsequent resorption and is replaced by bone. Synonym(s): cartilage bone, replacement bone en ...

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★リンクテーブル★

リンク元	「置換骨」
関連記事	「endochondral」「bone」

「置換骨」

　　[★]

英

cartilage bone, replacement bone

ラ

os cartilagineum

同

一次骨 primary bone、軟骨性骨 endochondral bone

関

骨形成、骨化、軟骨内骨化

「endochondral」

　　[★]

• adj.

• (医)軟骨(基質)内で(起こる)

「bone」

　　[★] 骨