What happens when we sleep?

What regulates the sleep-wake cycle in humans?

• The cardiovascular system

• The respiratory system

• The circadian rhythm

• The digestive system

During which stage of sleep do delta brain waves occur?

• Stage two

• Stage one

• Stage three

• Stage four

What is the primary function of the chemicals produced during the dreaming stage of sleep?

• To regulate breathing

• To increase heart rate

• To paralyze the body

• To enhance memory

How much of their lives do humans typically spend sleeping?

• One quarter

• One third

• One half

• Two thirds

What is a potential health risk of sleeping less than 7 hours per day?

• Increased risk of chronic conditions

• Reduced stress levels

• Improved concentration

• Enhanced physical performance