The Body Clock
The control and regulation of our sleep-wake cycle is a complex physiological process. However, put simply, our daily rhythm is under the influence of a small gland at the back of our brain called the HYPOTHALMUS.
This little gland responds to the light-dark cycles in nature to control our circadian rhythm , otherwise known as our 24 hour body-clock. The hypothalamus has close links and connections to a series of other glands producing hormones which control a series of other body functions.
In particular the hypothalamus has links to the Pituitary gland and the Adrenal glands. This chain of glands, known as the HPA axis, may be implicated in the development and perpetuation of fatigue states. Therefore, supporting the regulation in function of these glands could be of great benefit in managing your fatigue. The hypothalamus is the most accessible gland for us to influence, because of its responsiveness to light, regular routine and external cues.
You can see the effect of the body-clock on some of our physiological systems in the table below.
The function of the hypothalamus is complicated; this link will give you some more accessible information.
The body-clock can be desynchronised quite easily. Shift work and jet lag mean that our rhythm is out of sync with the day night cycle around us. Illness and the effects of stress may also disrupt the function of the hypothalamus, causing a chain reaction through the HPA axis.
If we become unwell, we may sleep during the day, and miss the daily cues of meal times and other routines. If we are ill for a long time, and lose the structure and routine of a working week, we may find that this loss of regularity combined with the effects of the stress involved in coping with a long term health issue, impacts on our internal rhythms.
Research has identified that people with CFS/ME, show signs of a desynchronised hypothalamus. You can find references for this work here,
Next: The Effect of Light