Sleep Stages and Cycles
Describe the stages of sleep and outline the order in which we progress through these stages during a typical night’s sleep.
 
Sleep progresses through several stages in a cycle that repeats multiple times throughout the night. The stages are divided into non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.
Stages of Sleep
NREM Stage 1 (Light Sleep)
- This is the transition from wakefulness to sleep.
 - It lasts about 1-7 minutes.
 - Muscle activity decreases, and eye movements slow.
 - Brain wave activity shifts from alpha waves (relaxed wakefulness) to theta waves.
 
NREM Stage 2 (Deeper Light Sleep)
- This stage lasts 10-25 minutes in the first cycle and lengthens in later cycles.
 - Brain activity slows, and sleep spindles (short bursts of brain activity) and K-complexes (sudden spikes) appear…
 
Sleep progresses through several stages in a cycle that repeats multiple times throughout the night. The stages are divided into non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.
Stages of Sleep
NREM Stage 1 (Light Sleep)
- This is the transition from wakefulness to sleep.
 - It lasts about 1-7 minutes.
 - Muscle activity decreases, and eye movements slow.
 - Brain wave activity shifts from alpha waves (relaxed wakefulness) to theta waves.
 
NREM Stage 2 (Deeper Light Sleep)
- This stage lasts 10-25 minutes in the first cycle and lengthens in later cycles.
 - Brain activity slows, and sleep spindles (short bursts of brain activity) and K-complexes (sudden spikes) appear…
 
Sleep progresses through several stages in a cycle that repeats multiple times throughout the night. The stages are divided into non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.
Stages of Sleep
NREM Stage 1 (Light Sleep)
- This is the transition from wakefulness to sleep.
 - It lasts about 1-7 minutes.
 - Muscle activity decreases, and eye movements slow.
 - Brain wave activity shifts from alpha waves (relaxed wakefulness) to theta waves.
 
NREM Stage 2 (Deeper Light Sleep)
- This stage lasts 10-25 minutes in the first cycle and lengthens in later cycles.
 - Brain activity slows, and sleep spindles (short bursts of brain activity) and K-complexes (sudden spikes) appear…
 
