Final answer:
Daily fluctuations in blood pressure, hormone levels, body temperature, pulse rate, and metabolism are controlled by circadian rhythms, which are daily changes that respond to our environment's natural light-dark cycle. Circadian rhythms play a crucial role in regulating various physiological functions and maintaining internal balance in the body.
Step-by-step explanation:
The daily fluctuations in blood pressure, hormone levels, body temperature, pulse rate, and metabolism are controlled by circadian rhythms which are daily changes that respond to our environment's natural light-dark cycle. Circadian rhythms are biological rhythms that take place over a period of about 24 hours. These rhythms play a role in regulating various physiological functions, including sleep-wake cycles, heart rate, blood pressure, blood sugar, and body temperature.
For example, our sleep-wake cycle is synchronized with the light-dark cycle. When it's dark outside, our body releases melatonin, a hormone that makes us feel sleepy. In the morning, when it gets light, melatonin production decreases, and our body releases cortisol, a hormone that helps us wake up and be alert. This daily variation in hormone levels helps regulate our sleep-wake cycle.
Similarly, changes in blood pressure, heart rate, and body temperature follow a circadian rhythm. For example, blood pressure tends to be lower during sleep and rises in the morning to prepare the body for activity. These daily fluctuations are important for maintaining homeostasis, the body's internal balance, and ensuring that physiological functions are properly regulated.