The human body is regulated by an internal biological clock in its day-to-day activities, such as feeding times and waking and sleeping times. This process is called the circadian cycle or circadian rhythm, which has a great influence on digestion, cell renewal and body temperature control.
Each person has their own internal clock and so humans have been classified in the morning, which are those who wake up early and wake up early, the evening, who are those who wake up late and late, and the middlemen.
Physiology of the human circadian cycle
The circadian rhythm represents the 24-hour period in which the activities of a person's biological cycle are completed and sleep and appetite are controlled. The sleep period lasts about 8 hours and the wakefulness lasts for about 16 hours.
During the day, mainly by influence of light, is produced cortisol, which is released by the adrenal glands and this hormone is usually low at night during sleep and increases early in the morning to increase wakefulness during the day. This hormone may also increase in periods of stress or be higher in chronic conditions, which may compromise the proper functioning of the circadian cycle. See what the hormone cortisol is for.
At dusk, the production of cortisol decreases and increases the production of melatonin, which helps to induce sleep, ceasing to be produced in the morning. For this reason, some people who have difficulty sleeping, usually take melatonin at dusk to help induce sleep.
Circadian rhythm disorders
The circadian cycle may be altered in some situations and may cause sleep disturbances and lead to symptoms such as excessive daytime sleepiness and insomnia at night or even cause more serious health problems. Learn about circadian cycle disorders.
