Home > Uncategorized > Circadian Rhythms – another scientific namesake

Circadian Rhythms – another scientific namesake

December 23, 2006 Leave a comment Go to comments

While the scientific reasoning of ‘Circadian Rhythms’ was getting some traction in the research world, it caught my attention for its name…. And lo’, at the end of reading it all, I was almost doubly sure (and so would you be) that it jus’ properly justifies my blog title. Now, this raises a big chicken-and-egg question –> which came first, my blog name or this concept?

Before you make a judgment, remember that I had an older blog… long before I started this one… which carried the same title. Neways, here is some dope on the scientific interpretation of this.

Are you sleepy sometimes in the afternoon? Do you seem to handle physical tasks more easily late in the day? If so, you already know about circadian rhythms.

Your body has more than 100 circadian rhythms. Each unique 24-hour cycle influences an aspect of your body’s function, including body temperature, hormone levels, heart rate, blood pressure– even pain threshold. Understanding how these cycles interplay is fascinating. And, in some cases, you may be able to plan your day to take advantage of your body’s natural rhythms.

How your body keeps time
In your brain is a type of “pacemaker” called the suprachiasmatic (soo-prah-ki-az-MAT-ik) nuclei. This area of your brain regulates the firing of nerve cells that seem to set your circadian rhythms. Scientists can’t explain precisely how this area in your brain “keeps time.” They do know your brain relies on outside influences, “zeitgebers” (ZITE-ga-berz), to keep it on a 24-hour schedule.

The most obvious zeitgeber is daylight. When daylight hits your eyes, cells in the retinas signal your brain. Other zeitgebers are sleep, social contact and even regular meal times. They all send “timekeeping” clues to your brain, helping keep your circadian rhythms running according to schedule.

Rhythms control your day
Almost no area of your body is unaffected by circadian rhythms.

Sleep and wake It may seem you sleep when you’re tired and wake when you’re rested. But your sleep patterns follow a circadian rhythm. You’re most likely to sleep soundly when your temperature is lowest, in the wee hours of the morning. You’re also most likely to awaken when your temperature starts to rise around 6 to 8 a.m. As you age, your brain’s “pacemaker” loses cells. This changes your circadian rhythms, especially noticeable in how you sleep. You may nap more, have disrupted sleep and awaken earlier.

Temperature Your temperature is lowest when you’re inactive. And activity can make your temperature rise. But despite these factors, your temperature also follows a definite circadian rhythm. In the late afternoon, your temperature can be as much as 2 degrees Fahrenheit higher than in the morning. And it will rise and fall even if you never see daylight.

Hormone production Almost all hormones are regulated, to some extent, by circadian rhythms. Cortisol affects many body functions, including metabolism and regulation of your immune system. Its levels are highest between 6 and 8 a.m. and gradually decline throughout the day. If you change your daily sleeping schedule, the peak of cortisol’s cycle changes accordingly.

Cardiovascular system More strokes and heart attacks occur in the morning than at any other time of day. This makes some people wonder if morning exercise is safe. But experts contend morning changes in your body–not exercise– may be responsible for cardiovascular problems. Blood clots most rapidly at about 8 a.m. Blood pressure also rises in the morning and stays elevated until late afternoon. Then it drops off and hits its lowest point during the night. These changes occur independently of physical activity. Exercise at any time of the day is beneficial.

Pain tolerance Athletes who compete late in the day may perform better because they can “gain” without as much “pain.” Pain tolerance is highest in the afternoon. One study shows tooth pain is lowest in the late afternoon, a consideration when you schedule your next dental appointment.

Medication Scientists are looking at how circadian rhythms affect the way your body uses medications. One finding is that less anesthesia is needed to cause analgesia or drowsiness when administered in the afternoon. Experiments with cancer medications are trying to find the time of day when the drugs are the most helpful with the fewest side effects.

Stay on schedule
Changes in daily habits such as a short night’s sleep can disrupt your circadian rhythms. You may be able to stay “in sync” by keeping a consistent daily schedule.

Advertisements
  1. No comments yet.
  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: