WordNet
- any bone that develops within cartilage rather than a fibrous tissue
- remove the bones from; "bone the turkey before roasting it" (同)debone
- the porous calcified substance from which bones are made (同)osseous_tissue
- consisting of or made up of bone; "a bony substance"; "the bony framework of the body"
- a shade of white the color of bleached bones (同)ivory, pearl, off-white
- rigid connective tissue that makes up the skeleton of vertebrates (同)os
- having bones as specified; "his lanky long-boned body"
- having had the bones removed; "a boneless rib roast"; "a boned (or deboned) fish" (同)deboned
- 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
- tough elastic tissue; mostly converted to bone in adults (同)gristle
PrepTutorEJDIC
- 〈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
- (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]
- 軟骨[組織]
Wikipedia preview
出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2014/04/03 12:40:50」(JST)
[Wiki en表示]
Endochondral ossification |
Endochondral ossification shown progressing from normal chondrocytes (top) to degenerating ones, characteristically displaying a calcified matrix, (bottom).
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Endochondral ossification[1][2] 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,[3] the growth of the length of long bones,[4] and the natural healing of bone fractures.[5]
Contents
- 1 Growth of the cartilage model
- 2 Primary center of ossification
- 3 Secondary center of ossification
- 4 Appositional bone growth
- 5 Histology
- 6 Fracture healing
- 7 References
- 8 See also
Growth of the cartilage model[edit]
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[edit]
The first site of ossification occurs in the primary center of ossification, which is in the middle of diaphysis (shaft). Then:
- Formation of periosteum
- The perichondrium becomes the periosteum. The periosteum contains a layer of undifferentiated cells (osteoprogenitor cells) which later become osteoblasts.
- 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.
- 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[edit]
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[edit]
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[edit]
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.)
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[edit]
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[edit]
- ^ Etymology from Greek: ἔνδον/endon, "within", and χόνδρος/chondros, "cartilage"
- ^ "Etymology of the English word endochondral". myEtymolgy. Retrieved December 2009.
- ^ Netter, Frank H. (1987), Musculoskeletal system: anatomy, physiology, and metabolic disorders. Summit, New Jersey: Ciba-Geigy Corporation ISBN 0-914168-88-6, p. 130: One exception is the clavicle.
- ^ Brighton, Carl T., Yoichi Sugioka, and Robert M. Hunt (1973), "Cytoplasmic structures of epiphyseal plate chondrocytes; quantitative evaluation using electron micrographs of rat costochondral junctions with specific reference to the fate of hypertrophic cells", Journal of Bone and Joint Surgery, 55-A: 771-784
- ^ Brighton, Carl T. and Robert M. Hunt (1986): "Histochemical localization of calcium in the fracture callus with potassium pyroantimonate: possible role of chondrocyte mitochondrial calcium in callus calcification", Journal of Bone and Joint Surgery, 68-A (5): 703-715
See also[edit]
- Intramembranous ossification
- Ossification
Musculoskeletal system · connective tissue: bone and cartilage (TA A02.0, TH H3.01, GA 2.86–95)
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Cartilage |
- perichondrium
- fibrocartilage callus
- metaphysis
- cells (chondroblast
- chondrocyte)
- types (hyaline
- elastic
- fibrous)
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Bone |
Ossification
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- intramembranous
- endochondral
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Cycle
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- osteoblast
- osteoid
- osteocyte
- osteoclast
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Types
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Regions
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- subchondral bone
- epiphysis
- epiphyseal plate/metaphysis
- diaphysis
- Condyle
- Epicondyle
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Structure
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- osteon / Haversian system
- Haversian canals
- Volkmann's canals
- connective tissue (endosteum
- periosteum)
- Sharpey's fibres
- enthesis
- lacunae
- canaliculi
- trabeculae
- medullary cavity
- bone marrow
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Shapes
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- long
- short
- flat
- irregular
- sesamoid
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anat (c/f/k/f, u, t/p, l)/phys/devp/cell
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noco/cong/tumr, sysi/epon, injr
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UpToDate Contents
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English Journal
- Collagen catabolism through Coll2-1 and Coll2-1NO2 and myeloperoxidase activity in marathon runners.
- Henrotin Y, Labasse A, Franck T, Bosseloir A, Bury T, Deberg M.SourceBone and Cartilage Research Unit, University of Liège, CHU Sart Tilman, Liège, Belgium.
- SpringerPlus.Springerplus.2013 Dec;2(1):92. Epub 2013 Mar 8.
- To determine the influence of marathon on the serum levels of two markers of cartilage degradation, Coll2-1 and its nitrated form, Coll2-1NO2, and of a marker of neutrophils activation, the myeloperoxidase (MPO). Coll2-1, Coll2-1NO2, total and active MPO were measured in 98 marathon runners without
- PMID 23519606
- Curcumin: a new paradigm and therapeutic opportunity for the treatment of osteoarthritis: curcumin for osteoarthritis management.
- Henrotin Y, Priem F, Mobasheri A.SourceBone and Cartilage Research Unit, University of Liège, Institute of Pathology, Level +5, CHU Sart-Tilman, Liège, 4000 Belgium ; Physical Therapy and Rehabilitation Department, Vivalia, Princess Paola Hospital, Marche-en-Famenne, Belgium.
- SpringerPlus.Springerplus.2013 Dec;2(1):56. Epub 2013 Feb 18.
- The management of osteoarthritis represents a real challenge. This complex and multi-factorial disease evolves over decades and requires not only the alleviation of symptoms, i.e. pain and joint function but also the preservation of articular structure without side effects. Nutraceuticals are good c
- PMID 23487030
- Preferential therapy for osteoarthritis by cord blood MSCs through regulation of chondrogenic cytokines.
- Lo WC, Chen WH, Lin TC, Hwang SM, Zeng R, Hsu WC, Chiang YM, Liu MC, Williams DF, Deng WP.SourceDepartment of Neurosurgery, Taipei Medical University Hospital, Taipei, Taiwan, ROC; School of Medicine, Taipei Medical University, Taipei, Taiwan, ROC.
- Biomaterials.Biomaterials.2013 Jul;34(20):4739-48. doi: 10.1016/j.biomaterials.2013.03.016. Epub 2013 Apr 1.
- Osteoarthritis (OA) is a common rheumatic disease associated with imbalanced cartilage homeostasis which could be corrected by mesenchymal stem cells (MSCs) therapy. However, MSCs from different origins might exhibit distinct differentiation capacities. This study was undertaken to compare the thera
- PMID 23557858
Japanese Journal
- Preparation and Characterization of Integrated Condylar Biomimetic Scaffolds: A Pilot Study
- iPS細胞を用いた難治性骨軟骨疾患への取り組み (パネルディスカッション iPS細胞と整形外科医療)
- 教育研修講座 軟骨代謝研究の変遷と将来 : トランスレーショナルリサーチの難しさとその評価
★リンクテーブル★
[★]
- 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
[★]
骨