Melatonin And The Circadian Rhythm


August 3, 2010

By Jody Smith

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.



Author: Leslie Carol Botha

Author, publisher, radio talk show host and internationally recognized expert on women's hormone cycles. Social/political activist on Gardasil the HPV vaccine for adolescent girls. Co-author of "Understanding Your Mood, Mind and Hormone Cycle." Honorary advisory board member for the Foundation for the Study of Cycles and member of the Society for Menstrual Cycle Research.