Circadian Cycle Definition and Meaning
What is Circadian Cycle?
The circadian cycle is the biological clock that regulates and programs the physiological functions of the organism in a period of one day or 24 hours.
The circadian cycle is framed in a day as defined by the etymology of the word circadian that derives from the Latin circa that indicates “approach”, dies that means “day” and the suffix – anus that refers to “something related to”.
In this circadian sense it is what is related to a period of one day and a cycle is the periodic repetition of a set of events.
In biology, the circadian cycle, circadian clock, or biological clock is the daily repetition of the physiological phenomena of living organisms.
Circadian cycles in plants, for example, control photosynthesis, flowering periods, sugar metabolism, and cell growth.
The circadian cycle generally respond to periods of light and dark, wakefulness, and sleep. The circadian cycle is the one that regulates the programming and control of the circadian rhythm.
The main human clock is made up of more than 20,000 neurons that form a structure called the Suprachiasmatic Nucleus (NSQ). The NSQ is located in the hypothalamus and receives information directly from the eyes.
For this reason, the sleep cycle is one of the most important cycles in the regulation of circadian rhythms that affects the release of hormones, eating behavior and body temperature.
In this sense, we have the example of the increase of cortisol during the day as a response to the stress of our body when it is active and the secretion of melatonin by the pineal gland for the induction of sleep at dusk, as regulatory mechanisms of the circadian cycle of being human.
The circadian cycles of living organisms are generally associated with periods of light and darkness, as daily rhythms can vary. These rhythms determined by biological or circadian clocks are called circadian rhythms.
The 2017 Nobel Prize for Medicine of the Year was awarded to Jeffrey C. Hall, Michael Rosbash and Michael W. Young for discovering the molecular mechanisms that regulate the circadian rhythm.
The circadian clock regulates and controls the circadian rhythm through interrelated molecules (proteins) in cells throughout the body.
The study of circadian rhythms is called chronobiology and different types of chronotypes have been determined in humans. The founder of chronobiology is the Romanian biologist Franz Halberg (1919-2013).