Periods of non-REM sleep are characterized by decreases in muscle tone, heart rate, breathing, blood pressure, and metabolic rate. All these parameters reach their lowest values during slow-wave sleep. In non-REM sleep, body movements are reduced compared to wakefulness, although it is common to change sleeping position. Periods of REM sleep, in contrast, are characterized by increases in blood pressure, heart rate, and metabolism to levels almost as high as those found in the awake state. Sympathetic nerve activity also tend to increase significantly during this period of sleep (Institute of Medicine, 2006). In addition, REM sleep, as the name implies, is characterized by rapid, rolling eye movements, paralysis of large muscles, and the twitching of fingers and toes (Purves,
Periods of non-REM sleep are characterized by decreases in muscle tone, heart rate, breathing, blood pressure, and metabolic rate. All these parameters reach their lowest values during slow-wave sleep. In non-REM sleep, body movements are reduced compared to wakefulness, although it is common to change sleeping position. Periods of REM sleep, in contrast, are characterized by increases in blood pressure, heart rate, and metabolism to levels almost as high as those found in the awake state. Sympathetic nerve activity also tend to increase significantly during this period of sleep (Institute of Medicine, 2006). In addition, REM sleep, as the name implies, is characterized by rapid, rolling eye movements, paralysis of large muscles, and the twitching of fingers and toes (Purves,