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脑是智能发育的物质基础。早在胚胎的第18天就出现脑细胞发育的基质神经板。胚胎10～18周脑的生长极快,至23周,大脑皮质的6层结构已基本定型。出生前3个月脑细胞的增殖最快,出生后细胞增殖减慢,6个月左右增殖停止,但细胞的发育和功能完善在4岁前极为迅速。出生时脑重约350g,6个月时达600g,3岁达900～1000g,为成人脑重的2/3。所以生前3个月至生后3岁是脑发育的关键时期。也是智能发育的重要时期,此期的营养也就显得特别重要。脑的营养需要脑细胞在增殖、发育期间,大量细胞分裂复制,轴突分枝,树突生长,突触联接,以及髓鞘形成都需要充足的营养供给。在脑细胞中,蛋白质和氨基酸的代谢十分活跃。细胞核中DNA和RNA
Brain is the material basis for intelligent development. As early as the first 18 days of embryonic development of brain cells of the substantia nigra. The embryo 10 to 18 weeks of rapid growth of the brain, to 23 weeks, the 6-layer structure of the cerebral cortex has been basically stereotyped. 3 months before birth, the proliferation of brain cells is the fastest. After birth, the proliferation of cells slows down and proliferation stops after 6 months. However, the development and function of the cells are extremely rapid before the age of 4. Birth weight of about 350g brain, 6 months up to 600g, 3 years old up to 900 ~ 1000g, adult brain weight 2/3. So 3 months before birth to 3 years after birth is a critical period of brain development. It is also an important period of intellectual development, this period of nutrition is also particularly important. Brain nutrition requires sufficient supply of brain cells for proliferation, development, massive cell division and replication, axonal branching, dendritic growth, synaptic connections, and myelination. In brain cells, protein and amino acid metabolism is very active. DNA and RNA in the nucleus