All living organisms exhibit different types of regularly repeated sleeping behaviour or their timings, feeding, waking, reproduction, migration, hibernation, etc. Many diurnal animals come out for their daily activities before sunrise and many nocturnal animals do their activities during the night. Organisms have an inbuilt and nearly automatic rhythm that repeats itself at about 24 hours of intervals which was proposed by Erwin Banning.
What is sleep rhythm?
Sleep rhythm is defined as the timings of sleep and wakes during the 24 hours of the periodic cycle which is processed by or regulated by the physiology of the circadian rhythm/ biological rhythm or known as the sleep-wake cycle, which is defined under the biological clocks. The study of these biological rhythms is known as Chronobiology.
Two main theories about the biological clock:
Two main theories are given about the biological clock mechanism that is as given below:
- The pendulum theory: In this theory, the organism does its activities according to its own intrinsic timing equaling 24-hour intervals.
- Relaxation oscillation theory: In this theory, an organism acquires a rhythmic and cyclic geophysical event going on all the time and this theory is widely accepted for explaining the biological clock’s functioning.
Other observed cycles for biological rhythm:
There are several other observed cycle lengths for the biological or circadian rhythms:
A clock with a cycle of approximately 24 hours. A special graph, named, actogram which represents the activity of an animal or plant during the 24 hours.
A clock with a cycle of approximately 12 hours which is a tidal period.
A clock with a cycle of about half a month (~ 15 days).
A clock with a cycle of about a monthly active period.
A clock with a cycle of about a year (~ 365 days).
How to control Circadian Rhythm?
Control of Circadian Rhythm and Role of Melatonin Hormones: Circadian rhythms are controlled by a biological clock that is present in the section of the brain called the Suprachiasmatic nucleus, located in the hypothalamus. The suprachiasmatic nucleus release chemical signals in the pineal cells that produce a protein named ICER that is involved in producing melatonin, which is a lipid-soluble hormone.
This hormone responds according to the environmental cues and allows the organism to adjust to the changes in photoperiod over time, if the night is of 8 hours then melatonin will be released for 8 hours and if the night is of 10 hours then it will be for 10 hours when it is dark and is also involved both in the entrainment of the circadian cycle and in seasonal cycles too. When the melatonin rises, the Suprachiasmatic nucleus normally initiates the process of lulling our bodies to fall asleep. There are also some external factors by which these circadian rhythms are controlled.
Causes of disturbance in sleeping rhythm:
There are several causes that disturb the sleep rhythm:
- Usage of mobile phones before bedtime also affects the eyes
- Doing other activities at the time of sleep.
- Not having proper food.
- Irregular interval times of sleep during the day and night.
- By not giving proper rest to the body
- Overthinking, depression, anxiety, etc.
- Blue light is the strongest effect on circadian rhythm.
Different ways to keep sleep rhythm well:
- Avoid daytime naps, especially afternoon naps or long naps and long sleep during the day.
- Do regular physical activities so that your body lose some energy or feels enough fatigue to fall asleep at regular interval of time.
- Avoid using mobile phones before bedtime. Mobile phones release blue light rays which are harmful to the eyes and skin too.
- Exposure to low and high levels of blue light is recently considered to have the strongest effect on synchronizing biological rhythms in human beings and can cause serious health implications.
- Keep a regular or healthy food schedule. If you eat healthily, you can sleep properly.
- Create a comfortable environment around yourself by finding a suitable place and position.
- Do yoga or gym which is suitable for you in daily life.
- Stick to the sleeping schedule or circadian rhythm on which you sleep daily, do not compromise your sleeping time if it’s not necessary.
- Try to sleep in a dark room because in the dark melatonin hormone gets released which helps in sleep early.