The Sleep Factor: Sleep 101
Transcript
Hi there everyone and welcome to our sleep 101 series. So this is part one of our three part series on waking habits for better sleep. How we sleep is so important for overall health.
0:22
Most of us have some level of fatigue and I can't think of anybody who has not at some point in their life, missed a night of sleep for one reason or another. The problem with that is that when we extend interrupted sleep pattern for long periods of time, we can end up doing some real damage to a lot of different physiological systems in the body. Stress plays a big role in this. Because when we experience chronic stress over long periods of time a can bleed from just a bad night's sleep here and there, into chronic insomnia and long term sleep deprivation and we know that over time. Sleep deprivation can actually become another cause of elevated stress levels.
So, when you experience any kind of stress, whether that's good or bad, whether it's a threat or a challenge. If it's excitement or danger, the nervous system responds, as it should. With a flood of hormones, and among those hormones, cortisol and adrenaline. And these have multiple jobs to do as with everything in the body. It's more than just one job, but they're very related to your internal security system. And their job. In that capacity is to energize your muscles in your brain and keep your brain alert, so that you can take some kind of action to either remove the threat or remove yourself from that threat.
Now, that works brilliantly. If that threat is a one and done, kind of acute threat. But what happens in our typical modern Western life is that we have. Yes, one major threat here, but then we move from that threat into another threat and into another threat. And so we really don't get a release, or a relief, or a shutdown, a tuning down, of that state of arousal in our nervous systems so what the body does because its job is to keep you alive that nervous system keeps you alive, is it keeps that alert trigger turned up so that you can deal. Right. That's all it is. It's a way to keep you alive.
3:23
Now the other piece to this is that nervous system wants to maintain homeostasis in the body. Now homeostasis is a big word. Right. But basically, it just means keeping you alive and functioning at some level of optimization. And for the body that means the easiest way or the most efficient way. It doesn't necessarily mean the healthiest way. So, that means it's allowed to shut certain things down. If they are not necessary, because again it's trying to maintain homeostasis. And it's trying to keep you alive in the most efficient way possible. Anything that it thinks that you don't need to stay alive right now isn't going to get a whole lot of energy.
4:20
So, when it comes to sleep this can be a real problem because sleep is where your body rests and repairs itself. If your security system, your internal security system is keeping you awake all the time. Your body is not going to be able to function optimally because it's not been given the opportunity to rest and repair.
In today's episode we are going to begin this series by looking at some of the anatomy of the brain, and the anatomy of our sleep function. I just want to put out there on the table. First of all, that I am not a neurologist or a physician of any kind, I want to bring you this information in a way that you can wrap your head around it so that you can maybe start to take some of this information and apply it to your life in a way that will help you get better sleep every single day. And we only need to take small steps forward to do that, we don't need to change everything all at once. Everybody comes to the table with a different set of circumstances. So, I want you to begin to cultivate a little bit of curiosity here about how this all fits together with our overall health. We can't just flip a switch on one thing in the body, or in the mind or in our emotions and have it fixed everything because everything is connected. And I think we'll start to see this pretty obviously when we start to talk about the patterns of sleep, and how our brain works together with other systems in the body for sleep. So let's get started with our sleep factor, 101, and and look at some of our brain anatomy.
So we're just going to look at some of these areas in the brain and what their job is and how that relates to getting a good night's sleep or not getting a good night's sleep. All right, so let's begin with the hypothalamus. The hypothalamus is a peanut size structure that is really deep inside the brain, and it contains several groups of nerve cells that act as kind of a control center that affects our sleep and arousal. Now that word arousal sometimes has a sexual connotation. But in this case and in most cases when we're talking about the human body arousal just means your get up and go, your motivation to move. from a physiological state,
The hypothalamus acts as a connector really between two different systems, maybe more but the two that we're talking about today, it connects between our endocrine system which handles all of our hormones, and our nervous system. And it plays a part in a whole lot of essential functions in the body.
Now, remember I talked about the purpose of a lot of this connections in our body is to to achieve homeostasis a state of balance, a state of of enough wellness to keep you alive. so this is going to make sense with this list of functions that the hypothalamus connects.
First one is body temperature, which makes sense right we need to maintain an internal body temperature, no matter what the external temperature is, thirst. hydration levels, appetite and weight control. The hypothalamus affects our emotions, our sleep cycles, obviously that's why we are talking about it today, our sex drive, childbirth, blood pressure and heart rate, the production of digestive juices so it plays a part in our gut health, and then balancing bodily fluids.
8:46
Now, also within the hypothalamus within that connection inside the hypothalamus, there is a group of cells, a cluster of cells that they call the super schismatic nucleus and we are going to abbreviate that abbreviate that with SCN. so the SCN, this little group of cells receives information about light exposure directly from your eyes. And this particular group of cells the SCN. Once it gets that information about the light, it uses that information to help control your behavioral rhythm. Now, it doesn't control like what you do, but what they're talking about with that is your circadian rhythms, your sleep wake cycles. Okay, so this area of the brain is super important. It takes that information when you look outside when you see the sun and it says, Hey, the sun is out. We should be wakeful now. And then it takes that same information when it's dark outside when the eyes cannot receive light when they don't receive light, and it tells the rest of the brain, hey, we should be sleeping now.
Second area we need to be aware of is the brainstem. The brainstem is a super primitive part of your brain. This is where a lot of your, your fight, flight and freeze response happens. this is our stress response area, part of that. So the brainstem is at the base of your brain and it communicates with the hypothalamus and in that communication. It is controlling the transitions, your primitive brain this brainstem is controlling the transitions between being awake and being asleep.
The sleep promoting cells that are within the hypothalamus and the brainstem produce a brain chemical that is called GABA - g a b a. And when you see it. It's all in caps, because it's an acronym for gamma amino butyric acid. Again, we are just abbreviating to GABA. GABA is a neurotransmitter, that just means it's a chemical messenger, in the brain, and that messenger GABA will block specific signals in the central nervous system and slow the brain down.
11:35
And this is what is necessary we need that. We need something to tell the brain to slow down. In order for us to calm down enough for sleep. It provides really a very protective and calming effect on both the brain and the body. GABA relieves anxiety reduces stress, improves sleep. Overall, it can prevent the brain damage that is associated with chronic stress injury that we sometimes see.
The brain, naturally releases GABA at the end of the day to promote sleepiness, and allow a person to rest. How does it know the day is ending? It knows the day is ending because of the message that it gets from the hypothalamus when that SCN receives different messages about light. Okay, so when the light changes, this is what triggers GABA production, along with some other things that we're going to talk about in a minute.
Now, GABA has some other jobs too. And they've been a lot of studies on GABA. And what they found is that it really has an antimicrobial, anti seizure, anti antioxidant properties that can help treat and also prevent other conditions, like diabetes and high blood pressure, but for our intents and purposes, the big one is insomnia.
So we have got the hypothalamus the brainstem and now we're going to talk about the thalamus, which is another area of the brain that acts as a relay center for information from other senses, the other senses that we have so more than just sight.
13:29
It relays information from all of our senses to the cerebral cortex, which is the covering of the brain that interprets and processes information from short to long term memory. Okay, now. Stay with me, short to long term memory during most of the stages of our sleep the thalamus is very very quiet, and it quiets down when you're sleeping, to allow you to tune out the external world like everything about the external world, if you had to hear everything and get everything into your brain. you would never sleep. We need to tune that out, it's a tuner. Okay, so, so during most of our stages of sleep. It will tune everything else out, except for during REM sleep, rapid eye movement. During REM, the thalamus is really active then and it sends the cortex a lot of images and sounds and other sensations that fill up our dreams.
The thalamus is responsible during REM sleep for processing, all of the information of your day from short to long term memory, it's super important.
There are three stages of non REM sleep and then you have REM sleep. Okay, there's actually five stages of sleep as, as doctors talk about it, but they include waking, we're not going to talk about waking. I'm assuming all of you are still awake, are you still with me? Hopefully, you're still with me. Right. So waking is one stage. And then we have three stages of non REM, and then we have REM sleep. All right. So those are some of the stages, the thalamus is most active during REM sleep.
15:24
Okay, let's move forward here. Now we have the pineal gland. Now the pineal gland is located within the brain's two hemispheres and it receives signals from the SCN remember that that's that little cluster of cells up inside the hypothalamus. The SCN sends some signals to the pineal gland and increases, production of the hormone melatonin. So we know the SCN takes its information from light or light sources. And that is the signal that it's going to send to the pineal gland to produce melatonin,. You might have heard of melatonin, I think of melatonin as a sleepy time hormone. Okay, so it helps you get to sleep once those lights turn down at the end of the day.
16:20
The other piece to Melatonin is it's supposed to be higher at night. It's supposed to shut off during the day. And this is really important this balance. It's not about whether you have enough melatonin. It's about whether you have enough melatonin at the right time of day. So if you are never seeing sunlight it's going to be really hard for the brain to turn off the production of melatonin to allow you to come back and into a more wakeful state of being. So keep that in mind.
Melatonin is responsive to the type of light that your eyes are exposed to. And this is why it's important to really be aware of how much exposure, you have to that blue light from Tech in the evenings because that interferes with how the brain understands, day and night. All right.
17:27
Now people can stabilize your sleep, their sleep patterns, by taking small amounts of melatonin. If you want that to work it has to happen at the same time every day, because the body likes patterns, it wants habits, and it wants things to be as easy as possible. It doesn't necessarily mean it has to be correct, but it needs to be as easy as possible. So if we're going to take a supplement like melatonin, it needs to happen at the same time every day to make it as easy as easy as possible. The body just really doesn't want to work very hard, so it's going to take the easy way out every time.
The melatonin levels, over time, are important for matching the body's circadian rhythm to some kind of external cycle of light and darkness. So it's it's not about what you do, once it's about what you do, over and over and over again because like I said the body ones, easy.
Now, cortisol and insulin which are two other important hormones both for stress and for how the body functions, as far as energy production, both of those oppose melatonin production. So, you're supposed to have higher melatonin at night, to help you get to sleep. But if we have too much cortisol and too much insulin running around in the body at the same time, it's going to be really difficult for the body to produce enough melatonin to help you sleep.
This is why it's so important to keep our stress levels low, to be able to self regulate down regulate our stress levels enough to lower cortisol. This is why we don't want to exercise right before bed because that boosts our cortisol levels, and this is why we need to give ourselves more time between the last time we've eaten a meal and bedtime because every time we eat. Insulin is released into the bloodstream, to do its job.
We're going to talk more about that in part three, but for right now just know that we need to find a balance here we're looking for homeostasis. We're looking for balance.
Moving on from the pineal gland into the basal forebrain. This is not an area I was familiar with before this episode, but it happens to be an area that's near the front and bottom of the brain that promotes sleep and or wakefulness either one. And as part of the midbrain that acts as an arousal system, which means it an arousal system is something that gets you up and moving.
Here's how this works, this is, this is new to me too so I want to break it down slowly for us all . When you move and exercise, the body needs energy for that. It gets that energy from stored glucose and glycogen and it breaks down that stored energy from what you've eaten. Now there's a lot of steps here I'm skipping.
20:31
Whatever you've eaten it's gonna break it down into something called ATP adenosine triphosphate. And it uses that for energy. And then it burns that all up and in the process of burning that energy that ATP there is a chemical byproduct called adenosine that’s all by itself. Adenosine is a byproduct after you've exerted all this energy. When there's more of that, it triggers and supports your drive for sleep, which makes sense when you think about it right if you've been working hard, physically working hard at some point you're gonna feel tired. You're gonna feel tired and the reason you feel tired is because this chemical byproduct in the body.
Now, when we drink caffeine, caffeine actively counteracts that tiredness by blocking the action of adenosine. that's how that works. So, if you're waking up still tired in the morning, and then chugging that coffee or that five hour energy or whatever it is that you use for caffeine in the morning. That is the mechanism that's going on it's blocking this adenosine action in the brain.
21:58
Now the last area of the brain that we need to understand a little bit about when we're talking about sleep is the amygdala. Now this is a really small little area of the brain. You might have heard me talk about it. The amygdala is the fire alarm when there's a threat. Okay, so it's it's really quite closely linked in our stress response but the amygdala is a almond shaped structure that's involved in processing, our emotions.
22:39
And this is important because it's really active during REM sleep. Think back with me. What else is really active during REM sleep? The thalamus, right? The thalamus, which is where we process, short and long term memory, and it's connected to our amygdala, because the amygdala processes those emotions and encodes those emotions connects them with our short and long term memory. The stronger those emotions are then the stronger the memory will be and the longer it's going to stick around for us. And all of that happens during REM sleep. Interesting. Right?
Okay, so we have covered in part one. The basic brain anatomy for sleep. It was a lot. I know, but I hope that you can see here how some of these connections in the brain can start to bring some understanding, around the How the What the Why for getting a really great night's sleep.
If you're not there yet if you're not sleeping well on a regular basis. You know how important this is. So, we are going to continue next time with part two, and go through the four stages of sleep, and how that applies to every day, good sleep. So I hope you enjoyed this, and I will see you next time on The Work IN.
I’m Ericka
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