Circadian rhythm. It's not a dance beat. And it's not the noise cicadas make in the summertime, the one kids count in order to tell how hot the temperature is. The term "circadian rhythm" is from the Latin, meaning "around the day".
Circadian rhythm refers to your internal body clock, or your biological clock. Your circadian internal body clock is located in the suprachiasmatic nucleus (SCN). The SCN is a cluster of cells in the hypothalamus of your brain.
Your circadian rhythm has to do with your body's ability to regulate hundreds of processes to fit in a fairly orderly manner into a 24 hour cycle. This cycle roughly lines up with the 24 hour day of the (external) clock.
Blood pressure, brain waves, heart rate and hormone production are just a few of the processes controlled by your circadian rhythm. Not the least of these processes is your ability to sleep at night and wake up in the morning.
This can be supremely easy to take for granted ... until you can't do it anymore.
It's a suprisingly simple task to mess up your sleep wake cycle. Pull the midnight shift for awhile. Struggle with jet lag after living in a different time zone.
Being ill can kick it off. Or being up with a baby who doesn't sleep through the night can eventually mean you don't either.
In order to understand how our circadian rhythm works, you need to know something about melatonin. Melatonin is a hormone your body uses to put you to sleep.
Melatonin levels are supposed to start to rise two hours or so before it's time for sleep. Waning light is a signal for the body that it's getting on to melatonin time.
Plenty of things can and will disrupt our sleep wake cycle. New research suggests one of them is adolescence in combination with season changes and going to school.
A recent study at the Lighting Research Center at Rensselaer Polytechnic in Troy, New York, involved teenagers, sleep and melatonin. Turns out, their melatonin level begins its ascent 20 minutes later in the spring than in the winter.
This would stand to reason.