Circadian rhythm. This module is about understanding the underlying rhythm that really drives our sleep. There's actually two opposing forces that I'll get into in a minute. But I wanted to highlight the importance of circadian rhythm. We've all heard about it. circadian is derived from the Latin word, which means in essence around a day, and it's our internal biologic clock.

There'll be some science in here, and I promise I'm not going to go overboard, but I think it's important just for some background information, particularly for those of you who travel, those of you who cross time zones, shift workers, really kind of helps put things in perspective in terms of some of the factors that really affect our ability to get to sleep and stay asleep. And so the circadian rhythm is our internal biologic clock. And it's really a structure inside the brain called the super charismatic nucleus or SCM. So that is in the mid part of the brain and the hypothalamus. This little structure is really tiny. It's about the size of a pinhead.

So it's just microscopic, but it contains over 20,000 neurons. Neurons are cells within the brain. So it's very tiny structure, but very critical for our function in our ability to sleep. So how does it work? Well, the fcn signals travel to another structure called the pineal gland. And the pineal gland is responsible for melatonin production, among other things, but Melatonin is really the substance that helps us get sleepy at night.

It's a supplement. At least the United States is a supplement in Europe in some places, it's actually a prescription drug. But anyways, this little structure this tiny little pinhead, actually also controls some other functions like body temperature, secretion of hormones while we sleep, urine output and even blood pressure are all affected by the super cosmetic nucleus. So in essence, the circadian rhythm is usually thought of as a 24 hour clock and depending on the researcher, it's anywhere between 24.2 and 25 hours this experiments are actually done in sleep deprive patients who were blocked out from any external light. And they really felt that it was closer to 25 hours. But in reality, because of the spinning of our planet on access in the sun, it's generally 24 hours because it gets reset every day by light.

Some of the other things that can affect the circadian rhythm cycling like shift workers jetlag, we're all familiar with with that if you've crossed time zones, particularly multiple time zones, and this internal clock, it is able to be manipulated. And the way that we do that as healthcare providers and researchers is to use light therapy. So how does light therapy work? Well, by using brighter than normal daytime light, we can actually sort of reset the biologic clock a little bit faster. It is a way to kind of hack travel quickly. If you carry a little portable light source with I've got a light source that I use, particularly in the winter months.

I used to use it a lot when I work night shifts, and it's Sort of a way to reset the body and to help combat some of that delay, that usually takes several days to recover from jetlag, but the light therapy can really speed that up. I wanted to point out this concept. This is huge, and it's something that I never thought of. And I bet you many of you haven't thought of it either. And that is shift workers have a whole host of health problems. Did I just say Betcha, anyways, whatever.

Heart disease, gut disturbance, mental errors, accidents, death, divorce, substance abuse, psychiatric disturbances, personality disorders, anxiety, memory loss, it's all documented shift workers are at risk. And so this is a huge, huge issue. So something to consider. I'm not, you know, advocating quitting your job or anything but really sort of physic figuring out your unique physiology and biohacking sleep to get the most benefit from sleep, I think is really critical. For all of us, but particularly for those shift workers. So there are really two forces that help determine when we fall asleep or get to sleep and the circadian rhythm that's relatively static.

That's why when you travel time zones, you're you're you're lagging behind because it's sort of fixed on your reference point your your current reality. And then the other is homeostatic homeostasis is just where the body tries to restore balance naturally. And this fluctuates and what I mean is that, for example, the longer you stay awake, the more your body craves sleep, certainly you can get a second wind and that's partly due to stress hormones and body temperature. But really, the, the, the time awake really helps predict somewhat how the body is going to trigger the onset of sleep. I'll talk more about those forces in an upcoming module.