睡眠是人们正常的生理需要,但绝非睡眠时间越长越好。不同年龄的人对睡眠时间的需求是不完全相同的。年龄越小,大脑皮层兴奋性越低,对疲劳的耐受性也越差,因此需要睡眠的时间也越长。而到了老年,大脑皮层功能不如青年人那么活跃,体力活动也大为减少,所以需要睡眠时间也相应地减 Sleep is the normal physiological needs of people, but by no means sleep longer. The demand of people of different ages for sleep time is not exactly the same. The younger, the lower the excitability of the cerebral cortex, the more resistant to fatigue, so the need to sleep longer. By the elderly, cerebral cortex function is not as active as young people, physical activity is greatly reduced, so the need for sleep time is also reduced accordingly