Certified Rehabilitation Registered Nurse (CRRN) Practice Exam

Which stage of sleep involves light sleep that can be easily disrupted?

1. Stage 1

2. Stage 2

3. Stage 3

4. Stage 4

The correct answer is: Stage 1

Stage 1 sleep is characterized as the lightest phase of sleep and serves as the transition between wakefulness and deeper sleep stages. During this stage, a person may experience a sensation of falling, leading to sudden muscle contractions, often referred to as hypnic jerks. It is relatively easy to wake someone from Stage 1, as they may still be aware of their surroundings and can be easily disrupted by external stimuli. This stage typically lasts just a few minutes and represents a crucial part of the sleep cycle, as it prepares the individual to enter deeper stages of sleep. In contrast, the subsequent stages involve progressively deeper sleep, where it becomes more challenging to rouse the person and where physiological changes such as slowed brain waves and diminished responsiveness occur.