Circadian rhythms or Body clock…there is more to it than just SLEEP

The clock was first identified in Fruit flies. No doubt why Nobel prize winner Michael Rosbash said “I am very pleased for the fruit fly”.

As humans, we prefer to sleep at night and feel fresh during the day. But this is not due to habit we inculcate or based on any  work schedules or convenience. It is driven by our own body clock. Circadian rhythm is just not about sleep, it regulates many physiological functions including Blood pressure, Body temperature, Hormone secretion, Sleep-wake cycle, Heart beat, Metabolism, Cell cycle, Response to drugs and many more.

Where is the clock?

The clock was first identified in Fruit flies. No doubt why Nobel prize winner Michael Rosbash said  “I am very pleased for the fruit fly”.

Biological clocks are not made of cogs and wheels, but the area of the brain known as the suprachiasmatic nucleus is body’s master clock

A group of nerve cells in the brain called the suprachiasmatic nucleus, or SCN,  situated right above the point in the brain where the optic nerve fibers cross, controls circadian rhythm. The SCN controls the body’s temperature, and small fluctuations in temperature throughout the day trigger various cells in different organ systems in the body to be sleepy or active. This is how the SCN controls the release of melatonin, the hormone that makes one sleepy. Genes are also involved in regulating body’s clock and circadian rhythms.

What Melatonin does

Durinh night more melatonin gets secreted. This hormone signals the brain to go into sleep mode. When the sun rises, melatonin secretion hits low, and the brain’s awake circuits restarts.

Is light important for Body clock?

Every day between 2 and 4 PM, the majority of the human race enters a lull, complete with sudden sleepiness and a lack of focus Image

Light is the signal based on which body clock functions. When the eye senses light, it sends signals to the SCN. This resets the clock every day. Our body does this to make sure rhythms do not drift out of line with the environment. Although our rhythms cycle happens about once every 24 hours, if we opt for total blindness, humans actually tick a little more slowly ie, about 24.1 hours. Thus, if we didn’t have daylight we would get out of synchrony with night and day.  Precisely the reason because of which people in captive lose on day and night.

Things you did not know about Circadian rhythm

Do you feel sleepy post lunch. Blame it on circadian rhythm. Every day between 2 and 4 PM, the majority of the human race feels sudden sleepiness and a lack of focus. That’s because circadian rhythm goes down about 8 hours after wake up time. Some experts suggest taking a short power nap to get over this lull.

Teenager son or daughter suddenly behave like owls. Do not scream at them. Blame it again on circadian rhythm. As a teenage body goes through puberty, its circadian rhythm essentially shifts three hours backward. Studies of teenagers around the globe have found that adolescent brains do not start releasing melatonin until around eleven o’clock at night and keep pumping out the hormone well past sunrise.

It’s Circadian Rhythm that make you gain weight if you Snack at Midnight

It’s Circadian Rhythm  that make you gain weight if you Snack at Midnight.

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Did you know that blue light from ‘Digital Screens’ negatively affects health

We all take special care to protect our eyes from the sun’s harmful UV rays; but what about the harmful effects of blue light rays?
Usage of blue light emitting gadgets before bedtime prolongs the time it takes to fall asleep, delays the circadian clock, suppresses levels of the “darkness hormone” melatonin.

Sources of blue light include the sun, digital screens (TVs, computers, laptops, smart phones and tablets), electronic devices, and fluorescent and LED lighting.

As the day progresses, we actually move closer to the back lit devices


Impact on Sleep:

Digital Screens emit blue light which are so bright that at night, brain gets confused by that light.  Blue wavelengths—which are beneficial during daylight hours because they boost attention, reaction times, and mood—seem to be the most disruptive at night. This causes the brain to stop producing melatonin, a hormone that gives body the “time to sleep” commands. Because of this, digital screen light can disrupt sleep cycle, making it harder to fall and stay asleep.

Changes in sleep patterns can in turn shift the body’s natural clock, known as its circadian rhythm. Studies have shown that shifts in this clock can have devastating health effects because it controls not only our wakefulness but also individual clocks that dictate function in the body’s organs. Research also shows that it may contribute to the causation of cancer, diabetes, heart disease, and even obesity. 

Eyes and Blue Light:

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