Which statements are true concerning non-REM sleep? 1. Early ...

[cmoore54]

Which statements are true concerning non-REM sleep?
 
  1. Early stages predispose a person to apneic periods.
  2. PaO2 levels decrease by 5 to 10 mm Hg.
  3. Minute ventilation increases by 1 to 2 L/min during stages 3 and 4.
  4. The amount of time spent in these stages is less than 50 of the total sleep time.
  a. 1 and 2 c. 1 and 4
  b. 3 and 4 d. 2 and 4

Question 2

Which stage(s) of sleep is (are) shown in the figure?
 
  a. Stage 1 sleep c. Stages 3 and 4 sleep
  b. Stage 2 sleep d. Rem sleep

[Toya9913]

Answer to Question 1

ANS: A
The reduction in respiratory drive that occurs during the early stages of non-REM sleep (stages 1 and 2) predisposes the person to apneic periods during fluctuations between being awake and asleep. With the establishment of non-REM slow-wave sleep (stages 3 and 4), nonrespiratory in-puts are minimized, and minute ventilation is regulated by metabolic control. Minute ventilation decreases by 1 to 2 L/min compared with wakefulness. As a consequence, PaCO2 increases by 2 to 8 mm Hg, and PaO2 decreases by 5 to 10 mm Hg.

Answer to Question 2

ANS: B
Stage 2 sleep is characterized by relatively low-voltage background electroencephalogra phic ac-tivity, sleep spindles and K-complexes, absence of eye movements, and tonic activity on an elec-tromyogram.