Circadian Rhythm Sleep Wake-Cycle

Introduction

Have you ever wondered why you feel sleepy around your regular bedtime? It’s because of the circadian rhythm. In this blog, we gonna see how circadian rhythm makes us sleep and wake with some tips to follow. circadian rhythm sleep wake cycle

Let’s get into the short history section before moving on to the relationship between circadian rhythm and the sleep-wake cycle.

History of Circadian rhythm

Ah ha! Don’t skip it. A small Evolutionary story will make you understand the Circadian rhythm better.

Principle of the Universe: We are part of the universe. So, any change that occurs in the universe will also occur in our bodies.

Earth’s rotatory dance: We know that our solo dancer – Earth takes around 24 hours (a day) to rotate around its axis. This rotation causes changes in the environment throughout the day such as changes in light, darkness, temperature and humidity.

Survival of the fittest: The one who adapts to environmental changes will survive better than the one who doesn’t.

Birth of the circadian rhythm: As we are part of the universe, we living things need to adapt to environmental changes caused by Earth’s rotation to survive better. So our body developed a cycle called the Circadian rhythm, which syncs with the changes caused by the Earth’s rotation every 24 hours.

In simple words, Earth’s rotatory dance created a rhythm within living organisms.

So, our body changes and adapts to environmental changes to maintain a balanced state with the universe and at the same maintain a balanced state within the body.

If we don’t adapt and sync with the environmental changes or lose the balance within our bodies, we will be dis-eased.

Circadian rhythm sleep wake cycle

What does the term circadian rhythm mean?

Circadian means “approximately a day” and here rhythm means “sync in time or to flow” and also means “an activity that repeats in the same order”.

Circadian rhythm: Circadian rhythm is the natural physical, mental and cell-level changes that occur in our body the entire day, which syncs in time with the environmental changes caused by Earth’s rotation.

In simple words, like hair blowing with the air, Circadian rhythm means to flow with the environmental changes each day in the same order.

What maintains the Circadian rhythm?

Circadian rhythm is regulated by the Suprachiasmatic nucleus of the brain, which is also called the Circadian clock.

The Circadian rhythm is the tick-tock of the Circadian clock. But this clock is not accurate, it doesn’t know whether 24 hours have been over or not. Now, a question arises: what makes the clock run for 24 hours?

Every cell in our body has a rhythm that syncs with the rhythm of the circadian clock.

Resetting the Internal Clock

External factors, particularly light and darkness influence circadian rhythm. It is also influenced by food, stress, temperature etc. When sunlight falls on the earth, our body receives it and resets the clock that generates the circadian rhythm.

That means our body starts to repeat its daily work from the beginning of the cycle as soon as it receives the signal from sunlight.

Research shows that even without sunlight our Circadian clock will work regularly but not for 24 hours, a little more than that. Sunlight is the main factor that resets our inaccurate internal clock every day.

How does our body receive the sunlight?

Eyes are windows

The sunlight enters through our eyes (even when closed) and is received by the light-sensitive cells present in the eyes and from there, it passes to the brain, where it signals the circadian clock to reset.