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首页> 外文期刊>European journal of clinical nutrition >Morphological and physiological changes during growth: an update.
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Morphological and physiological changes during growth: an update.

机译：生长期间的形态和生理变化：更新。

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摘要

Skeletal growth and changes in body composition during growth present important variations; body mass index and lean body mass related to age show important gender differences. The process of ossification is developed in two different ways, endochondral and intramembraneous. The former is characterised by the formation of bone from growth cartilage. Intramembraneous ossification is characterised by the formation of bone from a mesenchymal structure, as occurs with the flat bones of the skull. During childhood and adolescence and up to the acquisition of adult stature, two phenomenons are produced simultaneously: the synthesis of new bone from growth cartilage due to the process of endochondral ossification, and modeling-remodeling of previously synthesized bone. Bone growth and mineralisation of its extracellular matrix are simultaneous phenomenons, the final result being the acquisition and maintenance of body bone mass. A positive calcium balance is necessary during adolescence in order to achieve the maximum peak of bone mass and even with the termination of longitudinal growth of bone, the process of mineralisation can last a further 4 years. Childhood and adolescence are the period of life in which the peak of bone mass must be achieved, and if during this time this does not happen there will be a greater risk for the later development of osteoporosis. Regulation of bone mass is a polygenic process and during recent years studies have been centred on the receptor genes of vitamin D and estrogens. A maximum calcium retention during adolescence may influence the achievement of a high peak of bone mass but at a certain level of calcium intake the calcium retention reaches a plateau. The expression of grams of hydroxyapatite per square centimetre has been used clinically, or expressed in volume as g/cm3. From birth until 3 years, the increase represents approximately 30% of the total increase, from 3 years until the beginning of pubertal development the increase is 20%. During pubertal development there is an increase of 30-40% and from the end of growth until the age of 21 years there is an increase of 15-20%. Both prepubertal boys and girls show a progressive increase of leptin levels during the years prior to the onset of puberty and until Tanner's stage 11 and higher levels are observed in girls in this period, possibly in relation to their earlier onset of puberty. This increase of leptin in girls during pubertal development suggests that leptin may be a link between adipose tissue and puberty.
机译：骨骼生长和生长过程中身体成分的变化呈现出重要的变化。与年龄相关的体重指数和瘦体重显示出重要的性别差异。骨化过程以两种不同的方式发展，即软骨内和膜内。前者的特征是生长软骨形成骨。膜内骨化的特征是由间质结构形成骨，就像颅骨的扁平骨一样。在儿童期和青春期直至成人成年阶段，会同时产生两种现象：由于软骨内骨化的过程而从生长软骨合成新骨，以及对先前合成的骨进行建模-重塑。其细胞外基质的骨生长和矿化是同时发生的现象，最终结果是获得和维持人体骨量。为了达到最大的骨量峰值，青春期期间必须有一个正的钙平衡，即使终止骨的纵向生长，矿化的过程也可以持续4年。童年和青春期是必须达到骨量峰值的生命周期，如果在这段时间内不发生骨质疏松症，则以后患骨质疏松症的风险会更大。调节骨量是一个多基因过程，近年来，研究集中在维生素D和雌激素的受体基因上。青春期最大的钙保留量可能会影响高骨量峰的实现，但在一定水平的钙摄入下，钙保留量会达到平稳状态。临床上已使用每平方厘米的克力磷灰石克数表示，或以克/立方厘米表示。从出生到3岁，增长约占总体增长的30％，从3岁到青春期开始，增长为20％。在青春期发育期间，增加了30-40％，从生长结束到21岁年龄段，增加了15-20％。在青春期开始之前的几年中，青春期前的男孩和女孩都显示出瘦素水平的逐渐升高，直到该阶段的Tanner's 11期和更高水平的女孩中都观察到了这一现象，这可能与青春期开始之前有关。青春期女孩瘦素的这种增加表明，瘦素可能是脂肪组织与青春期之间的联系。

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