Non-Rapid Eye Movement sleep stages.

Non-Rapid Eye Movement sleep stages.

• A. Normal Sleep Cycle
• B. Fragmented Sleep
• C. NREM Sleep
• D. Circadian Cycle

Answer: (C)

The concept being tested is identifying the portion of sleep without rapid eye movements. Non-rapid eye movement sleep stages are collectively called NREM Sleep. This part of the night comprises light to deep sleep, with distinct EEG patterns as you progress: N1 is light sleep, N2 brings sleep spindles and K-complexes, and N3 is the deep slow-wave sleep. A normal night features cycles where NREM stages precede REM sleep, which is when dreaming occurs and rapid eye movements appear. The other terms describe related but different ideas. A normal sleep cycle includes both NREM and REM; fragmented sleep means interruptions that disrupt sleep continuity; circadian cycle refers to the 24-hour rhythm governing sleep-wake timing.

The concept being tested is identifying the portion of sleep without rapid eye movements. Non-rapid eye movement sleep stages are collectively called NREM Sleep. This part of the night comprises light to deep sleep, with distinct EEG patterns as you progress: N1 is light sleep, N2 brings sleep spindles and K-complexes, and N3 is the deep slow-wave sleep. A normal night features cycles where NREM stages precede REM sleep, which is when dreaming occurs and rapid eye movements appear.

The other terms describe related but different ideas. A normal sleep cycle includes both NREM and REM; fragmented sleep means interruptions that disrupt sleep continuity; circadian cycle refers to the 24-hour rhythm governing sleep-wake timing.