Keeping Circadian Rhythms Synchronized and Operating on a 24-Hour Schedule

question 524

Multiple Choice

Keeping circadian rhythms synchronized and operating on a 24-hour schedule:

• A) is normally impossible because of sleep spindles.
• B) requires special photoreceptors in the eye to detect sunlight and communicate this information to the brain.
• C) occurs naturally when people are deprived of all time cues.
• D) requires the hypothalamus to release the neurotransmitter hypocretin.