人到老年,随着年龄的增长,会伴有相应器官及组织结构的退化,生理生化功能的减退及自稳机制的下降,具体有如下变化: 1.神经功能的变化:首先表现为老年人脑的神经元数量逐年减少。自50岁后,人的脑神经细胞数每年以1％的速度减少,照此推算至70岁时约有20％的脑细胞退化。但人脑细胞有足够的贮备,其数量远超过一生中所能利用的数量,故虽有相当比例的退化,但在一般情况下仍可保持正常功能。与此同时,老年人的脑的重 People to the elderly, with age, will be accompanied by the corresponding organ and tissue degeneration, physiological and biochemical functions decline and self-stability mechanism decreased, with the following specific changes: 1. Changes in neurological function: the first manifestation of the elderly The number of neurons in the brain decreases year by year. Since the age of 50, the number of human brain neurons decreases by 1% each year, and it is estimated that about 20% of brain cells degenerate by the age of 70. However, since there are sufficient reserves of human brain cells, the number of which is far more than the amount available for a lifetime, a considerable proportion of them are degenerated, but normal functions can still be maintained under normal circumstances. In the meantime, the brain weight of the elderly