Sleep is an important human function which is essential for good physical health and good mental health. Even though sleep is so important many people take sleeping for granted. They either sleep too much or more often than not sleep less than is recommended for good health. People will catnap rather than sleep, burn the midnight oil studying, play on the computer, or just insist that they are too busy too slee
Sleep is an important human function which is essential for good physical health and good mental health. Even though sleep is so important many people take sleeping for granted. They either sleep too much or more often than not sleep less than is recommended for good health. People will catnap rather than sleep, burn the midnight oil studying, play on the computer, or just insist that they are too busy too sleep.
The fact of the matter is that we spend about a third of our lives sleeping. It was once thought that a healthy body needed 8 hours of sleep a night. Newer research points that fact that no two people need the same amount of sleep, some people can get by with as little as 5 hours of sleep to maintain good health while others will need 8 or 9 hours of sleep. It all depends on our internal body processes and our natural circadian rhythms.
A circadian rhythm is the body's natural rhythm based on a 24 hour period. The internal clock of sorts is common among all living organisms; humans, plants and even microorganisms. The internal process regulates our biological, response to day and night and thus it has a great bearing on sleep. The Circadian rhythm is not our biological clock, but it is guided by our biological clock.
The biological clock is a group of molecules that are scattered throughout the body and are responsible for different processes such as the aging process.. The start or end of menses is governed by our biological clock.
The master clock
There is a master clock housed in the brain. The nerve cells, about 20,000 of the them, form the master clock and are called the suprachiasmatic nucleus (SCN). The brain location for the the SCN is the hypothalamus, an area implicated in moods, eating habits, body temperature, sleep cycles and many other psychological and biological functions.
Scientists have found a genetic component for Circadian rhythms and have been able to locate the genes responsible for circadian rhythms in humans, mice fruit flies, and some fungi. A change in the environment can also change the response from the Circadian rhythm and bring the body's equilibrium out of balance.
Circadian rhythms and sleep
Circadian rhythms have a strong role in sleep cycles. Simply put they are responsible for producing a hormone called melatonin, which is responsible for making us drowsy. The SCN is conveniently located just above the optic nerves and therefore they will receive sensations from the eyes which filter light. When it is dark outside the optic nerve will relay the information onto the SCN which will then produce more melatonin. Melatonin will cause us to become sleepy since night time is the normal time humans sleep. Of course there are exceptions, some people work the night shift etc but generally speaking this is the way we were biologically programmed.
Lifestyle can interfere with natural our Circadian rhythm
As stated before our Circadian rhythm is based on a 24 hours cycle, however our lifestyle may not be in sync with that cycle. A person who works nights or works on different shifts throws the Circadian rhythm off balance.
Jet lag is another lifestyle interference. Often people experience jet lag because their body has not had the normal amount of sleep in the routine that it is most accustomed to. This can happen on any plane trip where the traveler gets little sleep. It happens more often on trips where passengers cross different times zones and can effectively lose hours of sleep. For example, there is a three hour difference between New York and California, So if you took a 9pm flight from New York to California, and you normally go to bed at 12 am, you just lost three hours of sleep, if you stay awake in California until 12am because it is only 9pm there.
On the other hand, if you left California for New York and you had to wake up at 7am for a business meeting, your body is still on California time and thinks it is 4am. This is why you may feel unusually tired getting up at 7am New York time, even when you normally would have gotten up at 7am California time anyhow.
Circadian Rhythms and your health
Circadian rhythms are implicated in several health issues from disrupted sleep cycles, insomnia and other sleep disorders, to psychological disorders such as depression, seasonal affective disorder (SAD) and bipolar disorder just to name a few.
How Circadian Rhythms are studied in humans
Sleep researchers will study Circadian rhythms by influencing the environment. Since we know that light influences the Circadian rhythm researchers will change the lighting in the laboratory setting and test for alterations at the gene or molecular level.
This research can help in discovering new treatments or cures for small issues such as jet lag onto larger issues such as major sleep disorders.