Updated: Oct 16, 2021
Have you noticed how the birds start chirping at sunrise and at sunset? Does your cat wake you up at sunrise? These are all examples how nature is in tune with the 24 hour cycle.
Have you pondered the perfect timing of the start of the day and when the magnificent sun rises as it brings light to the earth and when the sun sets every single day? Everything happens like clockwork every moment, every day. This is the Circadian rhythm, which is a biological rhythm based on a 24-hour cycle of biological processes.
Circadian rhythm is defined by the Sleep Foundation as follows: “Circadian rhythms are 24-hour cycles that are part of the body’s internal clock, running in the background to carry out essential functions and processes. One of the most important and well-known circadian rhythms is the sleep-wake cycle.”
Notice that this definition says essential functions and processes. “Essential” is defined as something that we cannot do without, necessary and extremely important!
Therefore, other than the sleep wake cycle which is very essential , there are many other processes that are tied in with the circadian rhythm, like the release of hormones , which are the chemical messengers in your body to start or stop certain functions.
Some of these essential processes triggered by the release of hormones are your sleep cycle, physical activity, alertness, body temperature, immune function, and digestive activity.
Let us see one example of the essential process the sleep cycle:
When you wake up in the morning, glance at the sky for a few moments.
With that simple act, the nerve impulses from your optic tract detect the light from the optic nerve. At this point there is an interaction with your nervous and endocrine (hormone producing) system .
The SCN (suprachiasmatic nucleus) is a tiny region of the brain in the hypothalamus, situated directly above the optic chiasm, which is where the optic nerves cross as they make their way towards the hypothalmus. The neuronal and hormonal activities it generates regulate many different body functions in a 24-hour cycle. The SCN contains approximately 20,000 neurons.
The SCN interacts with many other regions of the brain. It contains several cell types that produce hormones that control blood pressure, hormones that influence the intestine for digestive activity and neurotransmitters as well! Some neurotransmitters are glutamate, GABA, dopamine, serotonin, norepinephrine and acetylcholine and many more which have not been identified yet!
So, the light entering the optic nerve stimulates the SCN. The pineal gland is then activated to reduce production of melatonin hormone which helps in wakefulness.
It is interesting to note that we have a long way to go to get a full understanding of the full functioning of the hypothalamus, pineal gland and SCN functions . A PubMed study “Melatonin, the pineal gland, and circadian rhythms” also says “Several studies have indicated that pineal melatonin feeds back on SCN rhythmicity to modulate circadian patterns of activity and other processes. However, the nature and system-level significance of this feedback are unknown.”
Thus, there is still much to learn about the Pineal gland, SCN and Hypothalmus.
However, what we do know is around us daily. The sun rises and sets. Nature responds to it. Since us humans are surrounded by artificial light it is important for us to remember to the simple things like :
· First thing in the morning , go for a walk and look up at the sky when you wake up to program your pineal gland to know that in 12 hours it must produce melatonin so that we have night’s sleep.
· Also lower your lights as evening approaches and turn off your blue light devices close to bedtime. Since we all have to check our messages on our devices, add a blue light filter to your computer or cell phones or wear blue light blocking glasses while working at night. The blue light can suppress melatonin production so filtering it out can help keep your circadian rhythm intact and can help you sleep better.
· Do your best to get 8 hours sleep at night so you go into a REM sleep and deep sleep. In TCM (traditional Chinese medicine) the body cycles through twelve two hours cycles every day and night when the organs are most active and going through a detox process.
See the diagram at the top of this article to see which organs are affected at what time.
Like western medicine’s study of the circadian rhythm and biological clock, even traditional Chinese medicine (TCM) theory studies many natural rhythms, including circadian rhythm (daily rhythm) that has been studied most, as well as syzygial rhythm (lunar rhythm) and seasonal rhythm (annual rhythm)!
The workings of body are amazing and the body is made to be intune with nature. One essential way is to keep up with the circadian rhythm which can have a profound impact on your health and life quality.