身高的这种变化,与生长发育使身体长高是不同的,它主要是由脊柱长度变化引起的。脊柱位于背部的正中,由24块椎骨、1块骶骨和1块尾骨组成。在每两块椎骨之间,有一块圆盘形纤维软骨,称为椎间盘。盘的中央是柔软而富有弹性的髓核;盘的周围是由无数层纤维软骨构成的一层层纤维环。髓核和纤维环共同作用,使椎间盘既坚硬又富有弹性,在承受压力时被压缩,除去压力后便会复原。 This change in height, which is different from the growth and development of the body, is mainly caused by changes in the length of the spine. Located in the middle of the back spine, the spine consists of 24 vertebrae, 1 sacrum and 1 coccyx. Between each two vertebra, there is a disc-shaped fibrous cartilage, called the disc. The center of the disk is a soft and elastic nucleus pulposus; the disk is surrounded by a layer of fibrous loops composed of numerous layers of fibrous cartilage. The nucleus pulposus and annulus fibrosus work together to make the intervertebral disc both stiff and elastic, compressed under pressure, and restored after pressure has been removed.