Week 1 recording 1 17 23 Biology of Sleep

Estimated read time: 1:20

Summary

In this insightful lecture by Karen Schell, we delve into the intricate biology of sleep, exploring the anatomical structures of the brain and their roles in sleep, the important physiological pathways involved, and the complex architecture of the sleep cycle. The discussion covers various brain structures like the thalamus, hypothalamus, and pituitary gland, and explains their functions in regulating circadian rhythms and sleep stages. The overview also highlights common sleep disorders such as insomnia, narcolepsy, and sleep apnea, emphasizing the significance of understanding these for both physiological and cognitive health. This foundational knowledge sets the stage for further exploration into the neurophysiology of sleep and its impact on overall health and well-being.

Highlights

Karen Schell guides us through the anatomical structures involved in sleep 🧠
Learn how the brain's physiological pathways interact during sleep 🤔
Discover the stages of sleep from REM to non-REM and their importance 💤
Identify how circadian rhythms affect our daily sleep-wake cycle 🌜
Explore various sleep disorders and their physiological implications ⚠️

Key Takeaways

Understanding sleep anatomy and physiology can help identify sleep disorders 😴
Key brain structures like the thalamus and hypothalamus play major roles in sleep regulation 🧠
Circadian rhythms regulate sleep-wake cycles and are influenced by natural light 🌞
Sleep disorders like insomnia and sleep apnea affect overall health significantly 😴🌡️
Maintaining good sleep hygiene supports both mental and physical health 💪🛌

Overview

Karen Schell's lecture offers an extensive overview of the biology of sleep, covering everything from anatomical structures to sleep physiology. The talk begins with a detailed look at brain areas like the thalamus and hypothalamus and how they support sleep regulation through interaction with other body systems. These systems help in processing sensory signals and maintaining body homeostasis even during sleep.

Emphasizing on the physiology of sleep, the lecture explains various pathways and mechanisms that facilitate sleep stages such as REM and non-REM, and how disruptions in these stages can lead to disorders. The importance of maintaining circadian rhythms for healthy sleep patterns is illustrated using day-night cycles and their impacts on hormonal secretions.

Towards the end of the lecture, Karen explores common sleep disorders including insomnia, sleep apnea, and narcolepsy, discussing their symptoms and effects. She underscores the importance of understanding sleep at a biological level to effectively manage or treat these conditions, highlighting the relationship between sleep quality and overall physical and mental well-being.

Chapters

00:00 - 01:00: Introduction to the Lecture Karen Shell introduces the second lecture on the agenda dated 1/17/23. The lecture aims to further explore the topic of sleep, specifically focusing on the biology, anatomical structures, and physiological pathways related to sleep.
01:00 - 05:00: Anatomical Structures Related to Sleep The chapter begins with an overview of anatomical structures related to sleep, focusing on brain anatomy. Each structure's function in relation to sleep is explained.
05:00 - 08:00: Oral Anatomy and Its Importance During Sleep This chapter discusses the basics of oral anatomy with a focus on its relevance during sleep. The content emphasizes understanding various terms and their locations in the brain, and how these can potentially influence sleep processes. Initial sections will delve into brain anatomy and functions, beginning with the spinal cord.
08:00 - 10:00: Respiratory System and Its Relation to Sleep This chapter provides an overview of the respiratory system, focusing on its interaction with sleep. It begins by describing the sensory tracts that extend down the spinal cord, which play a crucial role in transmitting information from the body to the brain and vice versa. These tracts are vital for relaying messages related to touch, temperature, and pain to the thalamus in the brain. The text also briefly mentions the cerebrum, highlighting its location at the front part of the skull and its significance as the principal and most anterior brain structure. This lays the foundation for understanding how the brain processes information crucial to both respiratory functions and sleep.
10:00 - 15:00: Key Terms in the Biology of Sleep The chapter 'Key Terms in the Biology of Sleep' explains the roles of different brain parts involved in sleep. It starts with the cerebrum, noting its division into two hemispheres (left and right) responsible for complex sensory and neural functions, as well as voluntary body activities. Then, it discusses the thalamus, described as a critical hub of gray matter in the forebrain. The thalamus is a pivotal point for information exchange within the brain, as fibers disseminate from the thalamus to the cerebral cortex in all directions, highlighting its multifaceted role in brain communication.
15:00 - 18:00: Explaining Physiological Pathways Associated With Sleep The chapter discusses physiological pathways associated with sleep, focusing on the relay of sensory and motor signals to the cerebral cortex and hypothalamus. The hypothalamus, an essential component of the brain containing various nuclei, serves as a critical link between the nervous and endocrine systems via the pituitary gland. It is located beneath the thalamus and plays a significant role as part of the lymphatic system.
18:00 - 23:00: Discussing Sleep Architecture and Patterns The chapter discusses parts of the brain with a focus on the pituitary gland. The pituitary is described as an oval-shaped gland located behind the nose and near the underside of the brain. It is attached to a structure known as the hypothalamus, resembling a stalk, which plays a role in connecting different parts of the inner brain.
23:00 - 30:00: REM and Non-REM Sleep Characteristics The chapter discusses the anatomical and functional aspects of various brain structures and their roles in sleep. It highlights the historical term 'tween brain' and describes components such as the thalamus and hypothalamus. The cerebellum is identified as a key structure in the hindbrain of vertebrates, crucial for sleep mechanisms.
30:00 - 40:00: Regulation of Sleep-Wake Processes The chapter titled 'Regulation of Sleep-Wake Processes' discusses various brain regions and their roles in controlling sleep and wakefulness. It highlights the importance of the hypothalamus, a central brain area vital for myriad body functions including mood, growth, and heart health. Additionally, it touches upon the involvement of the brain stem in motor control and its significant link to sleep regulation. Students are advised to familiarize themselves with the terminology, as it is crucial for understanding the sleep processes discussed in the class.
40:00 - 50:00: Cardiovascular and Other Physiological Pathways The chapter titled 'Cardiovascular and Other Physiological Pathways' begins by describing a part of the brain connected to the cerebrum and the spinal cord, emphasizing its composition which includes the midbrain, pons, and medulla oblongata. The midbrain is particularly highlighted for its role in movement coordination and housing visual and auditory reflex centers, situated between the forebrain and hindbrain. The pons is mentioned for its critical function in transmitting signals within the brain, supporting vital physiological processes.
50:00 - 60:00: Conclusion and Importance of Sleep The chapter titled 'Conclusion and Importance of Sleep' seems to discuss the brain's anatomy, specifically the forebrain, cerebellum, and medulla oblongata, which is described as a continuation of the spinal cord within the skull forming the lowest part of the brain stem and containing control centers for the heart and lungs. The mention of 'first five minutes of brain anatomy' suggests that this is a review or a conclusion of previously covered material. The text hints at future discussions where these anatomical terms will be revisited in the context of sleep, emphasizing the importance of understanding brain anatomy to comprehend sleep better.

Week 1 recording 1 17 23 Biology of Sleep Transcription

00:00 - 00:30 hello again this is Karen shell with your second lecture from your agenda dated 1 17 23. we'll continue with this lecture and hopefully you'll keep learning more about sleep as we go along as indicated on your agenda we're going to cover the biology of sleep and in this time we're going to explain that atomical structures related to sleep and explain the physiological Pathways associated with sleep
00:30 - 01:00 as we get started today we're gonna start with the anatomical structures related to sleep as indicated on this slide we're going to talk about the structures related to sleep through the brain anatomy I've listed and shown a picture of the brain and we're going to go through each of these a little bit just to explain their function and then
01:00 - 01:30 later on we'll talk about how they relate to sleep and upcoming weeks but I want you to be familiar with the each of these terms and where they're at in the brain and possibly how they affect sleep will will help you understand the process better the next three slides will cover the brain anatomy and some of the functions related to the brain the first one listed here is the spinal cord and we
01:30 - 02:00 know it has sensory tracts that Ascend down the spinal cord from the body to the body from the brain these tracts are responsible for carrying information to the thalamus the tissues carry the to touch temperature and pain messages from the body back to the brain the next one we have listed is the serum cerebium it's the principle and most anterior part of the brain and it's located in the front area of the skull consisting
02:00 - 02:30 of two hemispheres left and right it's responsible for complex sensory and neural functions and the initiation and coordination of voluntary activity in the body the next one is the thalamus it's a large mass of gray matter located in the dorsal part of the forebrain or the division of the forebrain the fibers reach out to the thalamus to the cerebral cortex in all directions and it's like a hub-like exchange of information it has several functions
02:30 - 03:00 including relay of sensory signals including mortars motor signals to the cerebral cortex and the hypothalamus is next and the hypothalamus is part of the brain that contains the number of nuclei that with various function and one of the most important function is the is it is the link to the nervous system to the endocrine system via the pituitary gland the hypothalamus is located below the thalamus and it's part of the lymphatic system
03:00 - 03:30 a little more information about parts of the brain you can read through this but the ones I really want to point out here is the pituitary gland where it's a small oval-shaped gland it's behind your nose near the underside of your brain and is attached to a hypothalamus it's a stock-like structure the inner brain is a is the go between it's
03:30 - 04:00 between um the right and left brain but it also has been known as the tween brain in older literature it consists of structures of either on on either side of the third ventricle and it is including the thalamus hypothalamus and so on cerebellum is the little brain it's a major function is the feature of the hindbrain of all vertebraes and the cerebellum plays an important
04:00 - 04:30 role in motor control and then we have the hypothalamusial gland it's a small area in the center of the brain and it's extension it's essential from any body functions from growth and development to mood and health heart health against some different terms that you need to be familiar with as we proceed through the class they will be um differently involved with with sleep so we have the brain stem the brain stem
04:30 - 05:00 is a Stark stock like part of the brain that connects this cerebrum and the spinal cord it's composed of midbrain ponds and medulla obliga and the midbrain allows you to have prevalence and coordination in your movement it's between the forebrain and the hindbrain and it's the center for your Visual and auditory reflexes ponds AIDS in the vital function of the brain by transmitting signals between the
05:00 - 05:30 forebrain and the cerebellum and the medulla obagana is a continuation of the spinal cord within the skull forming the lowest part of the brain stem and containing control centers for the hearts and lungs well the first five minutes of the brain anatomy was a lot to soak in I know but again that's just there a quick introduction to to um the brain anatomy And as we get further into sleep we'll probably bring some of those terms back up so it's
05:30 - 06:00 helpful for you to be familiar with them and also um know where they're located in the brain the next part I want to cover is the oral cavity because of the oral cavity is important for us during sleep if including obstruction to the airway so again be familiar with these different items that are listed and I also included a quick diaphragm of a normal oral cavity we'll be talking later on about abnormal cavity that can how it
06:00 - 06:30 can affect sleep okay let's talk a little bit about oral Anatomy we have the top and bottom lip they're a fleshy tissue a conducts connects the front of area of the cheeks there they are used in the human body for facilitating speech um they keep food between the teeth and it also um and guiding through the mouth the lips are able for suckling when infancy
06:30 - 07:00 and they're very sensitive and have numerous receptors on their surfaces to help determine temperature especially and texture of food then we have the hard and soft palate the palette has two is two divided into two parts the hard and soft palate the hard part is a solid immovable roof of the mouth and attaches the teeth and gums for me in Arch the soft palate is located behind this the hard palate and is toward the back of the throat and it's flexible area of the
07:00 - 07:30 mouth where gag reflexes occur the then we have the oropharynx that's part of the pharynx that lies between the soft palate and the hyoid bone the right tons and left tonsils are a couple of lymphoid organs um in they're present in the tract um they consist of the adenoid tonsil two tubal tonsils and two Palatine tonsils and the lingled tonsil these organs play a report and row in the immune system and then we have the tongue it's a
07:30 - 08:00 fleshy muscular organ in the mouth it's used for tasting licking and swallowing why are these important during sleep we can have an obstruction to sleep anywhere in the tract to the airway so it's kind of important to know where the obstruction occurs and why it occurs and this will give us a general idea of how it occurs in the oral cavity the next diagram on this slide is the
08:00 - 08:30 tracheon and the lungs and the components of each again obstruction to airflow can occur in any of these areas so it's important to know where they're located and what their functions are okay let's do a quick review of the different parts of the trachea and the lung and lungs and again we want to know where these are located so that we when we talk about different forms of sleep apnea where the air reduction reduction
08:30 - 09:00 of airflow occurs so quickly we'll go over these terms we have the larynx it's the hollow muscle muscular Orient that forms the air passages to the lungs and includes the vocal cords and voice box the tracheal cartilages in the trachea or in the windpipe are tracheal rings in the tracheal reins have cartilages and the cartilage is strong but flexible it holds the airway open this straight to cartilage can support the trachea which
09:00 - 09:30 allows the movement of the flow of air in and out we have the right and left lung both loans are part of the respiratory system they're soft elastic spongy tissues that participate in gas exchange lower down in the bronchial tree we have the Carina the carinas that is where the trachea divides into the two lungs the left and right main stem bronchi that separates um basically
09:30 - 10:00 air movement into both both sides of the lungs right and left bronchus um is the difference between it's the one goes into the right lung and one goes into the left lung and the difference between right and left is the short the right is shorter and has a wider angle and the left is longer and narrower and um also the right bronchus is more vertical to the than the left then we get into the bifurcation of the trachea
10:00 - 10:30 the trachea is the division of trachea into the right and left bronchi and it um occurs at the fifth or sixth level of the thorax and um it's rigid like as well between the diverging bronchi and then we get to the air exchange and the bronchioles they're smaller branches of the bronchial Airways and they include the terminal bronchioles and the respiratory bronchioles with start of uh the I guess
10:30 - 11:00 delivering of air to the alveoli so that the gas exchange can occur before we go any further there's probably um the next six slides or so are going to cover some important terms in the biology of sleep I think it's important for you to be familiar with these terms as we go through the semester because we're going to bring them out and revisit them on how they affect sleep during some of the courses we're taking so as we get started the first one I
11:00 - 11:30 have most is the pineal gland and that's the function for the control and develop of sexual traits melatonin is another big one melatonin is a hormone that's produced by the pineal gland and is involved in regulating sleeping and waking cycle among other things adenosine uh it's a sleep inducing the new it releases neurons that are involved in metabolic functions and adenosine is also involved in the
11:30 - 12:00 process of sleep particularly in the the control and start of sleep the next one I have listed is just prior to going to sleep it's called The Wake but relaxed also have listed circadian rhythms this is the 24 ounce hour cycle and it's Unique per individual it includes sleep and wakefulness we'll talk about some of that during um sleep that happens
12:00 - 12:30 with your temperature and everything like that later super cosmetic nucleus in the light is a small region of the nuclear the nucleus is a small region of the hypothalamus the gland that's found in the brain and it's very small it interacts with other areas of the brain and controls circadian rhythm throughout through the secretion of several body and brain chemicals such as peptides and neurotransmitters I sleep through a polysomic graph
12:30 - 13:00 includes awaken alert these are beta waves we'll show the difference between the different wavelength frequencies once we get into that uh interpreting sleep test sleep stages include sleep theta waves hallucinations hypnogotic sensation and slip five minutes usually a nonsense of five minutes that's sleep stage one a lot of times our our patients um either spend a really long time in stage one because they can't fall asleep
13:00 - 13:30 which is on abnormal um should be out of stage one in within five minutes others can go right into Rim sleeping skip stages with different disorders of sleep and we'll again go into those a little bit more in detail as we go through scoring a sleep test and what's Normal and abnormal Hypno God gig Sensations are sensations of falling or floating and sometimes
13:30 - 14:00 they're incorporated into our memories um again we'll talk about those when they happen during sleep you may have had an episode of that we can explain those a little bit later stage two sleep is a little deeper sleep it has a periodic appearance as sleep spindles and they're very identifiable when you look at the police on the graph sleep talking occurs on the stage um sleep so it it's usually within the first
14:00 - 14:30 um first period of of sleep within the first 20 minutes and last 20 minutes so five minutes of stage one and then you go into different stages of sleep progressively with stage two lasting 20 minutes again we can see in some of the testing that people get into stage two and never proceed to the deeper sleep because of their sleep disorders so we'll talk about that again they're usually theta waves mixed in with the K complexes or sleep spindles sleep
14:30 - 15:00 spindles are a rapid burst of of the brainwave activity stage three is a transitional stage into stage four delta waves occur slow wave sleep it occurs only in a few only a few minutes to a deep sleep so again when we get in definition of um our night of sweet what's Normal and abnormal we'll look at the different ways stage four sleep occurs into a deep sleep
15:00 - 15:30 um we used to differentiate between stage four and three but we call it now a Delta wave slow wave sleep bedwetting can occur uh sleepwalking occurs can occur it can last up to 30 minutes and as we progress deeper into deeper sleep it's just before we get into REM sleep if sleep is normal stage five or REM sleep occurs this is again um the heart rate changes breathing
15:30 - 16:00 becomes irregular rapid eye movement and they become um muscle tension that they don't move around again we'll talk about how that happens when we get into the more normal an abalone sleeps and also the gentle and gentle genitals become aroused during stage five talk a little bit about REM sleep it's rapid eye movement AKA paradoxical sleep can be called Ram or paradoxical it's a
16:00 - 16:30 reoccurring sleep stage during which vivid dreams commonly occur in humans and it's that paradoxical sleep we go into Rim several times during the night following the staging of sleep as with the night progresses the worm periods get longer we know that sleep benefits um help in memory consolidations we know that concentration improves mood improves moderate
16:30 - 17:00 hungers it reduces up obesity obesity and improves the immune system insomnia is a reoccurring problem of uh or failing to stay asleep okay this is the last slide I have on some common terms of sleep um I probably have about six more pages we can get into we'll talk about those as we move along through the semester but I wanted to make sure you had these on you're familiar with because we're gonna be talking about them rather
17:00 - 17:30 quickly um narcolepsy narcolepsy is a sleep disorder characterized by uncontrollable sleep attacks it's pretty interesting and we will go into depth on that sleep apnea is a sleep disorder where temporary cessation of breathing occurs during your sleep and repeats uh is repeated with momentary Awakenings which patients often don't remember that they woke up it can occur during different stages of sleep we have obstructive
17:30 - 18:00 sleep apnea and Central sleep apnea and we'll we'll differentiate the tube and how we test for each and how we treat for each and then sleep Terrors sleep tears happens during stage four it's characterized by episode of and which sleep wake up is suddenly and extreme in an arousal and panic again for most people that have sleep Terrors sometimes the Observer that's watching them is frightened by what happens during a
18:00 - 18:30 sleep Terror and um a lot of times the individual doesn't recall having them when they wake in the morning okay now we get into the second outcome for this for this lecture for the 17th of January to explain this physiological Pathways is associated sleep I know the first half of this lecture was a little long and possibly boring
18:30 - 19:00 but we really needed to get a handle on our own knowledge of the different definitions and terms so that we can make this part of the lecture more meaningful so good job hanging in there we'll continue on as we get started with this section I want to take a moment just to describe a couple different um I guess extra terms that will will be referring to one of them is sleep
19:00 - 19:30 architecture and um all of us have the inherent architecture that we're so that sleep is supposed to bring on to us um and basically in normal sleep architecture there's a pattern of sleep and that pattern exists of two different main types of sleep and they include the REM sleep rapid eye movement sleep or non-rapid eye movement sleep which can contains the one two three and four sleep so the non-rem Sleep has three different
19:30 - 20:00 stages they're all a feature different depths of sleep and can by be identified through the brain waves polysomnogram eye movements and muscle tone I've included in this slide uh Grant I guess a graph a diagram or whatever you want to call it a histogram of um sleep architecture in a normal night of sleep and you can see that we go through the
20:00 - 20:30 various stages of sleep throughout the night and as we progress into Rim our Rim gets a little longer each time that we go into rim and uh this is a kind of the a period of time over time What stages of sleep we're in and how we get to ram in um we'll talk a little bit more about that as we talk about the different disorders and these graphs can look very different from that but this is what a normal sleep architecture should look like
20:30 - 21:00 depending on the individual and how many hours they sleep this slide just depicts that graph a little bit clearer you can see the different cycles of sleep there's five listed in here during an eight hour sleep our first cycle goes into one two three two then to Rim second cycle usually starts at two stage two three and two and back to rim and then the third cycle can you you can wait for
21:00 - 21:30 your free and go one two three two back to rim with the four cycle into one two awaken briefly and then fifth cycle is one two rim and then two again A lot of times we wake up in the morning and we we remember our dream uh first thing it's probably because you were still in room while you were sleeping while you were asleep dreaming and so that that particular dream stays with you a little bit and you can sometimes remember it um so Rim is kind of a stage in where
21:30 - 22:00 that deep sleep occurs the body regenerates the brain works harder our heart rate goes up and dreams occur so now we're going to cover the two types of sleep both RAM and non-rem sleep we know that RAM and non-rem sleep alternate and the alterations between non-rimming room is really not fully understood there's a regular cycling or absent sleep stages are associated with
22:00 - 22:30 Sleep disorders first we're going to talk about Ram itself rapid eye movement sleep you may have noticed in your bed partner or animals even the rapid eye movement when they're asleep that is is an indication that they're in the deep sleep it's a low voltage mix frequency brain wave activity with muscle atonia burst of Rapid Eye movements you'll notice that
22:30 - 23:00 on the polysomnogram that it's pretty identical I identifiable by comparing the actual brain waves with the eye movement and the muscle tone on the recording it's in Rim we see often see Sawtooth waveforms and that's called Theta activity there's also Alpha activity and which is a smaller wave um we see Rim period last one to five
23:00 - 23:30 minutes and it progresses uh in length during the different phases of sleep throughout the night as as a sleep episode progresses there's lots of muscle tone and reflexes and 80 of the Vivid dream recall results from this stage of sleep we know that Rim is important for the mem for memory consolidation um a lot of times we see um when you've stayed up for a long
23:30 - 24:00 amount of time um we can see re Rim Rebound in which Rim gets uh you start off in room earlier it lasts longer a lot of times it just is there to make up for the sweep you missed previously so sometimes that Rim rebound takes effect next we're going to cover the four stages of non-rimp and the slow wave sleep these
24:00 - 24:30 are also associated with distinct activity and Physiology will kind of go into those a little bit this week but probably get into them deeper as we move through the semester we use the EEG tracing to show these characteristics and changes of the stages and you'll be able to score them through the night on how much sleep is in each stage the next stage of non-room sleep that
24:30 - 25:00 we're going to talk about is stage one and again it's the transitional role in The Sleep cycling sleep stage cycling it is from wake to the first stage of of non-rim typically it lasts up to one to seven minutes on the initial cycle the first cycle it can be two to five percent of your total sleep and it's the again the transition from wakefulness so the EEG shows rhythmic noise to low voltage
25:00 - 25:30 mixed frequency waves um and it usually like I said is the first um stage of sleep and it's very short the next stage of non-rim we'll talk about is stage two we know it lasts 10 to 25 minutes and the first initial cycle again it lengths with each successive cycle so it composes about 45 to 55 of the
25:30 - 26:00 total sleep episode um it can require more intense stimulus to be awake from stage two and the activity on the EG is low voltage mixed frequency and is has the presence of cave complexes uh also it's a hypothesized that that the stage of sleep the sleep spindles are important in memory consolidation
26:00 - 26:30 and um a person learning a new task can have higher incidence of density of sleep spindles than those with the control group stages three and four or or slow wave sleep they're collectively three and four are collectively refurbed as slow waste sleep we used to uh differentiate
26:30 - 27:00 between three and four when we were doing scoring but they Consolidated that scoring method to make it we just score slow away sleep it occurs during the first third of the night and has a very distinct characters uh the it has a increased show in the EEG shows higher voltage slow wave activity the arousal threshold is the highest for all the non-rem state stages in stage four and the stage lasts only a few minutes and
27:00 - 27:30 constitute three to eight percent of sleep total sleep next we're going to talk about in the next few slides about the physiological Pathways associated with sleep physiological and health on how sleep patterns change over the individual's lifespan the sleep wake system is thought to be regulated by the interplay of two major processes one that promotes sleep and
27:30 - 28:00 one that promotes or maintains wakefulness humans spend about one third of their lives to sleep yet most individuals know a little about sleep sleep is a universal need of all higher life forms including humans absolute which has been has serious physiological consequences we're going to cover some of those specifically with with certain parts of the body and give you a little more in-depth detail what happens to
28:00 - 28:30 them if your sleep deprived of sleep foreign body system changes that occur during sleep um in and we'll talk about normal sleep right now in it it's well tolerated in the healthy individuals it may compromise some of the fragile balance of individuals with verbal vulnerable systems such as heart disease diabetes obesity
28:30 - 29:00 conditions those things can affect um how your body reacts or changes during sleep if those things are present then physiological changes also can occur okay in the next couple slides we're going to take a look at the physiological Pathways associated with sleep we're going to look at the process between RAM and non-ram with the differences let's look at brain activity we know
29:00 - 29:30 that in non-rem it decreases from wakefulness and in Rim it increases in a motor and sensory areas while other areas are similar to non-rem heart rate or the heart rate in non-rem slows from wakefulness but increases and varies compared to Rim in a non-rem in rim blood pressure we know in non-rem it decreases from wakefulness but increases up to 30 percent higher and varies from non-rem
29:30 - 30:00 pathetic nerve activity decreases from wakefulness but in non-rem but in Rim it increases significantly from wakefulness and muscle tone it's in non-rem is similar to wakefulness but in Rim it's absent okay let's look at blood flow to the brain in not non-rem it decreases from wakefulness but in Rim increases from
30:00 - 30:30 non-rem and depending on the brain region how much respiration respiration decreases from wakefulness but increases and varies for non-rem in Rim but they show brief stoppages or cough suppressed Airway resistance in non-rim increases from wakefulness that's but in uh Rim increases and varies from wakefulness
30:30 - 31:00 body temperature is regulated in in non-rem at a lower set point than weightfulness but in rim shivering initiation at lower temperature than during wakefulness and not regulated or no shivering temperature drifts towards that of a local environment and then sexual arousal in not non-ram occurs infrequently and it is greater in rim
31:00 - 31:30 greater than non-ram and rim okay in the next few slides we'll dig in a little bit deeper into the physiological Pathways associated with sleep through the different uh Pathways of of the body okay let's look a little more specifically into each individual pathway let's start with the cardiovascular the autonomic nervous system activity causes the primary changes in blood
31:30 - 32:00 pressure heart rate that occur during sleep increased blood pressure heart rate occur with the K complexes arousals and large body movements there's an increase of myocardial infarction in the morning to the increase in heart rate and blood pressure that accompany waking okay let's take a look next at the sympathetic nerve activity we know that the sympathetic nerve activity decreases in non-rem sleep but
32:00 - 32:30 there is a burst of sympathetic nerve activity during non-rem sleep due to a brief increase in blood pressure and heart rate that follows the K complexes remember that non-rem sleep includes stage one two three and slow wave and K complexes are in stage two during the respiratory pathway we know that ventilation and respiratory flow change and become increasingly faster and more erratic specifically during REM
32:30 - 33:00 sleep and we notice we can notice that without a polysomnom gram and we can see that in our bed Partners at times when they're in REM sleep so REM sleep suggests hypoventilation but it can also occur in non-rim sleep um factors that contribute to [Music] um changes in respiratory ventilation and flow can be due to some of the anatomy
33:00 - 33:30 that we covered at the beginning of the slideshow or or it can be to several things like a lower um pharyngeal muscle tone A reduced rib cage movement increased upward Airway and resistance cough reflex that's suppressed hypoxia ventilatory response is also lower and arousal response to respiratory resistance is the lowest cerebral blood flow can also be affected
33:30 - 34:00 in non-rem sleep it's reduced has reduced blood flow and Metabolism metabolism and blood flow increase in some brain regions during REM compared to wakefulness the pathway in the renal sleep for the renal pathway is that we notice a decrease in excretion of sodium potassium chloride and calcium
34:00 - 34:30 during sleep in renal function we see changes in the renal blood flow during sleep that are complex involving the glomial glomerular filtration hormone secretion sympathetic nerves stimulation we also see that um there's a reduced renal flow during sleep right a decrease urine renal flow and
34:30 - 35:00 it's more concentrated because of these changes okay let's see growth hormones secretion usually occurs a couple a few first a few the first few hours after sleep onset and um then the thyroid hormone uh secretion takes place late in the
35:00 - 35:30 evening melatonin which induces sleepiness is likely to be reduced from uh from this and also um it's influenced by the Light Dark cycle and suppressed by lights so the endocrine system is complex and also affects um how we fall asleep and how long we stay asleep and why we fall asleep
35:30 - 36:00 let's talk a little about sleep wake regulation now processes promote sleeps process C maintains wakefulness we know that these two processes promote sleep and maintain wakefulness and the need for sleep is um accumulates across the days and Peaks just before bedtime at night and dissipates throughout the night as we get sleep so let's first talk about
36:00 - 36:30 processes process C is the is the waking is weight promoting and regulating is regulated by circadian rhythm it builds throughout the day and it serves um the counteract the process s and promote wakefulness and alertness it's serving to enhance sleep consolidation and the need for Sleep dissipates across the night so with the adequate nights rest
36:30 - 37:00 homeostasis drive for sleep is reduced and the Circadian rhythm waking drives uh begin to increase and the cycle starts over again and process sleep I mean in the absence of process C Total Sleep Time Remains the Same um but it's randomly distributed over the day and night therefore the processes also works to consolidate
37:00 - 37:30 sleep and wake in a fairly dis inct episode now process s is the process to drive sleep accumulates throughout the day it Peaks just before bedtime at night and dissipates throughout the night sleep processes regulated by neurons that shut down the arousal systems thus
37:30 - 38:00 allowing the brain to fall asleep many of these neurons are found in the hypothalamus and these neurons contain molecules that inhibit the nerve the neural communication and turn off the arousal systems during sleep um lots of these nerve cells causes a profound insomnia and inputs from other regions of the
38:00 - 38:30 brain also greatly influence the Sleep System these include inputs from the lower brain stem that relate information about the state of the body example would be a full stomach is conductive to conductive to fall asleep as well as an emotional and cognitive areas of the forebrain in addition the um there are inputs from the circadian system that allow the Wake Sleep System to synchronize with the
38:30 - 39:00 external day night cycle but is but it also overrides the cycle with with neces when necessary when necessitated by the environment will need such as light this sleep generating system includes neurons in the pons that intermittently switch from non-rimp to rim over the course of the night and these neurons send outputs to the lower brain stem and spinal cords that cause the
39:00 - 39:30 muscles to relax in REM sleep chaotic and autonomic activity is characterized by the REM sleep and other um outputs are sent to the forebrain including activation of The Culinary color generic Pathways to the thousands to activate the EEG
39:30 - 40:00 hope that makes sense we'll go through it again as we go through this so let's review slightly and think of the sleep wake regulation we have the Sleep generating systems in the brainstem we talked about the hypothalamus and the lower brain stem the emotional and cognitive area of the forebrain the neurons in the pollens the spinal cord that causes the muscle atonia and the forebrain
40:00 - 40:30 the sleep wake regulation so the weight generation systems of the brain stem provide wakefulness being generated by ascending arousal system from the brain stem that activates the forebrain structure to maintain wakefulness two major Pathways that originate in the upper brain stem the first pathway being upper ponds and the second pathway being the the upper brain stem this inputs Travers the basal forebrain through the
40:30 - 41:00 sibo inputs Traverse or travel through the basal forebrain through the cerebral cortex circadian rhythms the 24-hour clock this is the 24 hour clock that we talked about and um it has molecular mechanisms that underlie that activity of that circadian clock the genes remove re rhythmically expressed contribute to the main aspects
41:00 - 41:30 of the cellular function including the glucose lip and lipid metabolism signal transition secretion oxidative metabolism and others suggesting that the importance of this circadian system in many Central aspects of life uh probably many of you have experienced a change in your clock especially I think change and shift work uh has affected all of us um I know uh from working in a sleep lab
41:30 - 42:00 and opening a sleep lab and also having to run the department during the day it really messed up my clock because certain times of the day my temperature body temperature would drop I would feel nauseated and sick because I had messed up my clocking and and then I could never get enough sleep because of my job and so I didn't get that restful sleep so I think this paying attention to your circadian clock is
42:00 - 42:30 important and understanding you know your body's trying to tell you to go to sleep you should go to sleep and that kind of thing um example for me was that when I had to train people in the sleep lab and work during the day I didn't get much sleep and always about I could tell at three o'clock my body temperature would drop and I would be freezing to death at that point in time I always knew it was coming so I'd always get a hot cup of tea or something because it was coming
42:30 - 43:00 and then another thing I'd be feel nauseated during the night when I had to stay up so I learned to eat something at 10 o'clock so that I wouldn't feel nauseated by two o'clock so I think just paying attention to your body really pays off and when you start to mess with the circadian rhythm to get it back in the order takes a little bit of effort one of the other things when I travel across Seas you know that really messes
43:00 - 43:30 up the clock as far as if I'm traveling east or west and um you know if they call it jet lag or they call it um sleep deprivation when you when you change your clock it takes you a couple days to reset it for that for that area so our body's pretty good about it but we have to pay attention to it let's talk a little bit about the super cosmetic which I could never say right nucleus it's responsible for regulating
43:30 - 44:00 the circadian rhythms in all of our organs it receives direct inputs from the class of nerves in the retina at that act as brightness detectors and which can reset the clock genes on a daily basis circadian super super cosmetic nucleus transmits the to the rest of the brain and body signals that bring all the daily cycles and synchrony and with the external day night cycle
44:00 - 44:30 so um we can talk a little later when we talk about treatment about light therapy and how we can control light to help us with our sleep cycle and to put our case circadian rhythm back into its regular rhythm um so I think it's important to um again pay attention to that and do everything you can to get uh your Rhythm back to normal so a lot
44:30 - 45:00 of night shift workers use knife stimulants in the middle of the light stimulus in the middle of the night so that when they do go to bed they've had that light stimulus that uh you know a lot of people at night turn down the lights work night turned down the lights but really the bright light is necessary for your Rhythm to get set we'll talk about that when we do talk about treatment so let's talk a little bit about sleep and thermoregulation kind of mentioned it in one of the slides before about how I could figure it out with my own body
45:00 - 45:30 when I my temperature dropped body temperature regulation is subject to the Circadian system influence so sleep wake can influence your body temperature how much sleep you get affects it body temperature is higher during the day than at night and at night there's a gradual decline in body temperature decrease in heat production and an increase in heat loss it promotes sleep onset and maintenance
45:30 - 46:00 and conversely there's a gradual increase in body temperature several hours before waking to get ready to wake up again this is something that you may be aware of as you stay up a light that you uh if your sleep gets disrupted as we come to the end of this presentation and I have to admit I'm a little bit sleep deprived right now I probably should have done this presentation early morning instead of late at night um for you but I think it's important to
46:00 - 46:30 realize that sleep is a process that is necessary for normal physiologic mental and emotional functions during the waking hours and I could test that my brain is a little bit fried tonight after this lecture because of all the complex complexity of sleep that we covered don't be worried we'll go over most of this again as we proceed through the semester so
46:30 - 47:00 um hopefully you'll understand it more this will just give you an introduction to it this presentation we know that in the development of the central nervous systems uh sleep is the foundation for the development of normal alertness attention and productive wakefulness sleep is necessary for healing and Recovery state and if sleep is abnormal the consequences can be physiological and physical illness
47:00 - 47:30 or even death treatment Sleep Disorders improve the physical well-being and can be instrumental in the treatment of medical and psychiatric disease so I think we know a lot more about sleep than when I started many years ago in the um in the development of the sleep lab and it's ever changing as we move forward with more research I guess what I'm trying to say is
47:30 - 48:00 there's always more to learn and we'll keep learning as we go through this semester and hopefully maybe one of one of you will be interested in sleep in the future and help with the research to find better ways to to get the rest we need um I've included some of the references I used for the preparation of this presentation here um I have more in future presentations that
48:00 - 48:30 will be helpful if you want to read more about it always look for it at the end of the presentation I'll list those references additionally I have a quiz on the next slide for you to just a quick simple quiz for you to review over some of the information that was covered in this presentation this was a probably a difficult for you to absorb all the information from this presentation but again it'll
48:30 - 49:00 give you an introduction to how complex sleep is and hopefully as we move through the semester we'll apply what have been on these first two presentations and bring them back into our um the next presentation so there'll be more easily absorbed and hopefully remembered I enjoyed doing this presentation and I look forward to our next one which I think covers let me look real quick
49:00 - 49:30 normal sleep in humans we actually get to get into some of the fine print that I believe that I get to join you in class life in one of the classes coming up on the 23rd so we'll see you then thank you for your attention and good luck get some good night's sleep before I see you again