Which of the following parts of the body controls the sleep-wake cycle?

• A. Hypothalamus
• B. Pituitary gland
• C. Thyroid gland
• D. Prefrontal cortex

Answer: (A)

Verified step by step guidance

1. Understand the sleep-wake cycle: The sleep-wake cycle is a daily pattern that determines when we feel sleepy and when we feel alert. It is influenced by various biological processes and environmental factors.
2. Identify the role of the hypothalamus: The hypothalamus is a small region of the brain that plays a crucial role in many bodily functions, including the regulation of sleep and wakefulness.
3. Explore the function of the suprachiasmatic nucleus (SCN): Within the hypothalamus, the SCN acts as the body's internal clock, helping to regulate the timing of the sleep-wake cycle by responding to light cues.
4. Differentiate the roles of other glands: The pituitary gland, thyroid gland, and prefrontal cortex have different primary functions, such as hormone regulation and cognitive processes, which are not directly responsible for controlling the sleep-wake cycle.
5. Conclude with the correct answer: Based on the understanding of the hypothalamus and its role in regulating the sleep-wake cycle, identify it as the correct answer to the problem.