论文部分内容阅读
一系列的数字能发挥我们的想象,看清难以置信的人体的微小世界。正常的人体,仅仅由109种元素中的26种元素组成(见表1)。 骨骼 婴儿出生时有350块软骨,要比成年人多150块。随着婴儿的生长发育一些骨骼会融合起来,这种骨骼的融合约在20岁时结束。到此时,一个成年人将有206块永久性骨头。 令人惊奇的是骨骼总重量不超过9千克,骨骼除了支撑身体,保护器官外,还是一个工厂,它能生成红细胞和白细胞。男人和女人一样,都有24根肋骨(见表2)。 牙齿 在婴儿时,上颌有10颗牙,下颌则比10颗要多,这些牙在出生前8个月即开始发生,一直到出生后6个月才长出来,到2岁半时,乳牙即可出齐。
A series of numbers can exert our imagination and see the incredible body’s tiny world. A normal human body consists of only 26 of the 109 elements (see Table 1). Bone babies are born with 350 cartilages, 150 more than adults. As babies grow and develop, some bones will fuse together, and the fusion of bones will end at about 20 years of age. By this time, an adult will have 206 permanent bones. Surprisingly, the total weight of the skeleton does not exceed 9 kg. In addition to supporting the body and protecting the organs, the skeleton is a factory that produces red blood cells and white blood cells. Men and women alike have 24 ribs (see Table 2). Teeth in infants, the maxillary 10 teeth, the mandible is more than 10, these teeth in the first 8 months before birth, until 6 months after birth to grow up to 2 years and a half, the deciduous Can be homogeneous.