AP PSYCHOLOGY

Detailed explanation-1: -Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. These natural processes respond primarily to light and dark and affect most living things, including animals, plants, and microbes. Chronobiology is the study of circadian rhythms.

Detailed explanation-2: -Listen to pronunciation. (sir-KAY-dee-un RIH-thum) The natural cycle of physical, mental, and behavior changes that the body goes through in a 24-hour cycle. Circadian rhythms are mostly affected by light and darkness and are controlled by a small area in the middle of the brain.

Detailed explanation-3: -Normal people have a circadian rhythm that is slightly longer than 24 hours. Every day, morning light and other behaviors reset the sleep-wake clock to a 24-hour schedule. Without light and this clock resetting, people’s sleep time will drift later and later.

Detailed explanation-4: -Regulation of circadian period in humans was thought to differ from that of other species, with the period of the activity rhythm reported to range from 13 to 65 hours (median 25.2 hours) and the period of the body temperature rhythm reported to average 25 hours in adulthood, and to shorten with age.

Detailed explanation-5: -Different systems of the body follow circadian rhythms that are synchronized with a master clock in the brain. This master clock is directly influenced by environmental cues, especially light, which is why circadian rhythms are tied to the cycle of day and night.