Which part of the brain plays a key role in regulating the timing of sleep?

• A. Amygdala
• B. Suprachiasmatic nucleus
• C. Cerebellum
• D. Medulla oblongata

Answer: (B)

Verified step by step guidance

1. Understand that the question is about identifying the brain structure responsible for regulating the timing of sleep, which relates to the body's internal clock or circadian rhythms.
2. Recall that the suprachiasmatic nucleus (SCN) is a small region located in the hypothalamus that acts as the master clock for circadian rhythms, including the sleep-wake cycle.
3. Recognize that the amygdala is primarily involved in processing emotions, the cerebellum in motor control, and the medulla oblongata in autonomic functions like breathing and heart rate, so these are less relevant to sleep timing.
4. Focus on the role of the SCN in receiving light information from the eyes and using this to synchronize the body's internal clock with the external environment, thus regulating when we feel sleepy or awake.
5. Conclude that the suprachiasmatic nucleus is the key brain part responsible for regulating the timing of sleep due to its control over circadian rhythms.