What are Circadian Rhythms?
Circadian rhythms are cyclic and persistent patterns of behavior, physical changes, and mental characteristics exhibited by most life on Earth, from the smallest bacteria to the largest redwood tree. These rhythms roughly follow 24 hour periods, reflecting the amount of time it takes for the Earth to complete a rotation. The study of circadian rhythms and the internal clocks which most creatures seem to have is known as chronobiology. Researchers study circadian rhythms to learn more about life on Earth, and how to treat various conditions such as sleep disorders. Several characteristics distinguish circadian rhythms. The first is that these changes will be retained through dramatic changes in environmental conditions. For example, an animal in the dark will still manifest periods of increased and decreased activity which correspond with a 24 hour cycle. Repeated input from external stimuli can also reset circadian rhythms, as anyone who has switched time zones is probably aware. In ad
Circadian rhythms are physical, mental, and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism’s environment. They are found in most living things, including animals, plants, and many tiny microbes. The study of circadian rhythms is called chronobiology. Are circadian rhythms the same thing as biological clocks? No, but they are related. Our biological clocks drive our circadian rhythms. What are biological clocks? The biological clocks that control circadian rhythms are groupings of interacting molecules in cells throughout the body. A “master clock” in the brain coordinates all the body clocks so that they are in synch. What is the master clock? The “master clock” that controls circadian rhythms consists of a group of nerve cells in the brain called the suprachiasmatic nucleus, or SCN. The SCN contains about 20,000 nerve cells and is located in the hypothalamus, an area of the brain just above where the optic nerves from
Research conducted in caves, as well as in modern sleep laboratories where the environment is completely time-free, has proven that the human body is governed by built-in time setters, commonly referred to as an internal body clock. Over 100 body functions fluctuate between their minimum and maximum values once a day. Because such fluctuations in human functioning take about a day’s time to complete—roughly 25 hours—the term circadian rhythms was coined (circadian means “about a day” in Latin). Dr. Franz Halberg of Germany first used this term in 1959 to describe these changing body functions. Body Temperature, Light and Zeitgebers One of the most easily measured of these circadian rhythms is the body temperature. Healthy humans experience rhythmic variations in their body temperature throughout the course of each day. For most people, the difference between high and low values is about two degrees Fahrenheit (97 to 99), with the lowest value typically occurring in the early morning ho
The signals our body clock produces are called circadian rhythms (sir-kadian). Circadian is Latin for ‘about a day’, and it describes the changing levels of hormones and neurochemicals that control our sleep, activity and mood. When our body clock misses critical zeitgebers (body signals) such as bright morning light or evening darkness, its rhythm may shift, and as a result, your body will produce hormones at the wrong time, or stop producing the right amounts. When your sleep or mood suffers, you may likely have a circadian rhythm problem. Medical journals report that most mood and sleep disorders have an underlying circadian rhythm disorder.
Circadian Rhythms are our body’s natural cycles that control appetite, energy, mood, sleep and libido. When our body is out of sync with nature, we suffer from a Circadian Rhythm Disorder. Almost all of us, at some time during a year fall out of balance and suffer from sleep, mood or anxiety disorders. Fortunately, after decades of research, science has found the way to create circadian balance.
