Final answer:
Circadian rhythm is the biological rhythm that helps reset our internal clock to align with environmental changes, such as light and dark cycles, and manages various biological functions including sleeping and waking.
Step-by-step explanation:
The biological rhythm that allows us to reset our internal clock in response to changing environmental factors, especially light, is known as the circadian rhythm. This rhythm cycles about every 24 hours and is controlled by a structure in the brain known as the biological clock, located in the hypothalamus above the pituitary gland. The circadian rhythm coordinates daily fluctuations in various bodily functions such as body temperature, sleep-wake cycles, blood pressure, and the release of hormones like melatonin, which is stimulated by darkness and inhibited by light.
Circadian rhythms help organisms stay synchronized with the Earth's 24-hour cycle, contributing to homeostasis, or the body's ability to maintain a stable and balanced internal environment. When our circadian rhythm becomes misaligned due to travel across time zones or shift work, we can experience symptoms like insomnia, anxiety, or depression. Fortunately, strategies such as exposure to bright light during certain times can help realign our biological clock with the external environment, alleviating these issues.