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The metaphysis () is the wide portion of a long bone between the epiphysis and the narrow diaphysis.〔Dorland's Pocket Medical Dictionary, 27th edition〕 It is considered a part of the growth plate, the part of the bone that grows during childhood and as it grows, it ossifies near the diaphysis and the epiphyses. The growth plate may be divided anatomically into three components based on tissue content: a cartilaginous component (epiphyseal plate), a bony component (metaphysis) and a fibrous component surrounding the periphery of the plate. The growth plate synchronizes chondrogenesis with osteogenesis or interstitial cartilage growth with appositional bone growth at the same that it is growing in width, bearing load, and responding to local and systemic forces and factors. During childhood, the growth plate contains the connecting cartilage enabling the bone to grow; at adulthood (between the ages of 18 to 25 years), the components of the growth plate stop growing altogether and completely ossify into solid bone.〔Visual dictionary of Merriam-Webster http://visual.merriam-webster.com/human-being/anatomy/skeleton/parts-long-bone.php〕 In an adult, the metaphysis functions to transfer loads from weight-bearing joint surfaces to the diaphysis.〔Encyclopedia Britanica, http://www.britannica.com/EBchecked/topic/377978/metaphysis〕 ==Clinical significance== Because of their rich blood supply and vascular stasis, metaphyses of long bones are prone to hematogenous spread of osteomyelitis in children. Metaphyseal tumors or lesions include osteosarcoma, chondrosarcoma, fibrosarcoma, osteoblastoma, enchondroma, fibrous dysplasia, simple bone cyst, aneurysmal bone cyst, non-ossifying fibroma, and osteoid osteoma.〔(【引用サイトリンク】title=New Jersey Medical School, Pathology Department Introductory Course on Bone Tumours )〕 One of the clinical signs of rickets that doctors look for is cupping and fraying at the metaphyses when seen on X-ray. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Metaphysis」の詳細全文を読む スポンサード リンク
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