Which of the following constitute the effects of normal sleep on the cardiovascular system?

1. Tachycardia during slow-wave sleep
2. Vasoconstriction during slow-wave sleep
3. Hypotension with significant phasic elevations during REM sleep
4. Slightly decreased cardiac output during non-REM and REM sleep
a. 1 and 2 c. 1 and 4
b. 2 and 3 d. 3 and 4

ANS: D
During REM sleep, there is hypotension with significant phasic elevations in blood pressure. During non-REM and REM sleep, cardiac output is slightly decreased. Bradycardia and vasodi-lation occur during slow-wave sleep.