okay we are going to start talking about the nervous system and pretty much talk about the various different parts of the nervous system from now until the next exam so today we're going to just kind of do a review about the different parts of our nervous system that you remember we have a central nervous system made of what rain and the final torque is my back like this is the central nervous system and then that central nervous system is going to talk to interact with the peripheral nervous system now information has to go to and from the central nervous system and interact with the peripheral nervous system which is basically everything else that is in the brain or fibers that are purple nervous system so the information is coming from the body and going to frames we say this is a parent information if the information is coming from the brain and spinal cord and going to the body and this has been a parent information okay so let's tape recorder versus Kevin break it down into its separate parts because it's a big nervous system okay and basically it has the person or person has two major components one portion is what we would call the sensory nervous system or the sensory division of the performances then the second major component would be the motor division of the purple nervous now the sensory division is all the different transitions of our bodies everything that we feel and taste and smell and touch and pain that you might have and life and muscles are sore on all those different sensations whether they're external sensations or internal sensations those are part of the sensory division and that information is the length of L to the central nervous system so this information is always going to be a parent now the brain and the spinal cord both are for integration now integration means basically thinking a lot of people assume that the spinal cord is only kind of like a superhighway for information there are logical information to go to and from the brain but in actuality in many different instances the trial court have the ability to also think to what the brain goes so the bottom part can interpret the sensory information and figure out what to do about it and whether it's the spinal cord or brain once it figures out what to do about the sensory information it's going to send information back to the body via the motor neurons and then we're going to do something about it so any information for the motor division is going to be e parent information so this is going to come from the brain from a LAN port go out to the body and have the body respond now there's two basic divisions of response one in the voluntary response one is voluntary response so we're going to break the motor division into two parts so one part is voluntary response which is the somatic nervous system and this is going to be voluntary we expend the only thing that we use for voluntary response are going to be skeletal muscles the in voluntary responses is going to be what we would call the autonomic nervous system now the autonomic nervous system is more than just skeletal muscle okay we're going to have information or let's say smooth muscle and cardiac muscle and glands these are going to be the biggest responders to the autonomic nervous system so both of these again are efferent information is coming from the brain the other motor division going to skeletal muscle by motor neurons are going to the autonomic nervous system by motor neurons we're going to have either voluntary or involuntary response now this involuntary response has a lot of different parts to it also and there's a lot of different ways for our body to respond and so we have two major divisions to our autonomic nervous system the first major division is called the sympathetic nervous system the second major division is the parasympathetic nervous system help remember the autonomous or the involuntary is all about noodles muscle contracting cardiac muscle contrasting and glands contracting for the most part okay so this would be things like a lot of our blood pressures to go up and respiration develop it's perspiration or salivation to change great and so the sympathetic nervous system affects all these but they affect them in opposite ways so the sympathetic nervous is typically for the most part makes things contract or secrete so if we talk about the sympathetic nervous system usually they go up they go faster so instead of nervousness and make heart rate pull up respiration go up perspiration go up all kinds of things are going to rise blood pressure goes up this is all part of the sympathetic nervous system parasympathetic on the other hand usually makes things calm down or shut down so heart rate will be free blood pressure will decrease respiration will decrease this is typically what's going on between sympathetic versus parasympathetic now a lot of times I'll hear people say sympathetic is fight-or-flight better known that nowadays at struck down okay whereas parasympathetic is much more like resting and digesting so remember heart rate have to go down on respiration goes down so that you can rest but then it also helps to speed up digestion that the only thing that really speeds up is the digestive tract with the parasympathetic nerve almost two thousand seven any questions about this now we are going to go into sympathetic and parasympathetic in a lot of detail because one of the other things that we find in that they also control our immune system and has a lot to do with our health and so we want to talk about how this affects our body health-wise because it has a lot of implications to people who have diseases and so really important for you to understand what the autonomic nervous system is doing to your patient whether it's helping them or not helping them alright the next thing I want to talk about is just kind of go over a little bit the difference between a neuron and a nerve to sort of refresh your memory so a neuron is a single that it's just like themselves we've been talking about neuron panel phospholipid bilayers integral membrane that has a nucleus they have all kinds of different organelles Golgi apparatus endoplasmic reticulum everything we've into something the only real difference is they look clinical they're not your typical looking cell and we're going to talk about how this change in shape also allows these neurons to send information through the body from one place to the other in comparison to this single salvo we also have something called a nerve and the nerve is just basically a group of neurons and it could be hundreds or even thousands of neurons all grouped together in one place now if you remember from your na'vi class many neurons have not all but they have this outer kind of fatty layer around it called myelin sheath so this is supposed to represent a single neuron right here like that picture that we just looked at this is a single neuron and it has a myelin around it now we're going to talk a little bit more about myelin in a few minutes basically myelin is insulation we're insulating this neuron because it's neuron is going to conduct electricity so life is cord that I have plugged into an electrical socket right here and then I have it plugged into my computer although if I didn't have its insulation around it what would happen if I grabbed a hold of this course job how okay there's no not quite covering where does the electricity go in me what we want is we want it to go from point A to point B we wanted to go from the socket to my computer to keep it charged up but if I have no insulation on it then it arcs out when I touch it it goes into me and we call it shorting out okay and we call it out all right so we don't want that to happen either with our neurons and we have these insulation sheets these myelin sheath wrapped around the neuron so that they don't short out now we also have a second layer of concern the second layer of insulation here this is called the endo neuron this goes around this single individual neuron now inside a nerve these neurons are bundled together they're grouped together and you can see that there's four major bundles inside this nerve and the whole these puzzles together is the perineum and so you have this connective tissue layer holding our bundles of neurons together by the way a bundle of anything in biology is what we would call vesicles so if you like bundle your hair in a ponytail we call a fascicle of hair anything that's bundled together so these neurons are a fascicle surrounded by the perineum and then you have multiple fascicles inside this nerve and it's surrounded by this external connective tissue layer which is the epidermis now probably I'm going to get when you were dissecting your chap in anatomy you saw nerve those white springy things that went through the cap while what you were looking at was just the epidermis if you took scissors and cut that nerve in half and try to look inside and we just look solid white because you can't see these individual neurons in several cells ok you can't see them with the naked eye very very small inside we also have some blood vessels that help you feed these neurons all the time but this is a way Keit neuron together and each individual neuron is usually in a nerve same kind so typically all these neurons would be sensory neurons or all these neurons would be motor neurons and so you'll hear people refer to them as sensory nerves or motor nerves sometimes there are some of these nerves that have a little bit of a mixture little sensory little motor inside and so you'll hear them calling mixed nerve so we have sensory members we have motor nerves yes mixed nerve depending on what kind of neuron is on the inside of this nerve now this is talked for a little bit we'll talk about motor neurons but I wanted to give you some examples of sensory neurons because we actually have more different types of sensory neurons and motor motor are stimulating muscles therefore skeletal muscle cardiac muscle smooth muscle but separate or as it is we do everything else so you don't have to memorize these we will go through these as we go along I just learned it give you a list and to look at right now sensory neurons oh okay here is a bit of a problem can also be referred to as sensory receptors okay now remember we've been talking about receptors how's that fitting on the outside of the cell that something binds to and we stimulate the cell get gates to open that type of thing now we're going to be talking about receptors and neurons and here little grouping neurons being at their nerves all those receptors on them so it is a little confusing and I wish somebody had a brought up would you know named of a different name but oh well so when we're talking about sensory neurons I'll try to be as accurate as I can I'm using the word receptor so you'll know it's actually the neuron so this particular sensory neuron they call a Meccano receptor and the channel receptors can do a few different things for it if they can help you to feel when your muscles are stretching or they help with equilibrium in your ear so you don't fall over they help with touch on the outside of your skin like pain and cold and heat that kind of thing chemoreceptors these are receptors we're going to talk a lot about tomorrow and they help us to determine sense of taste and sense of smell okay Osmo receptors will talk about these next week and they are all about monitoring blood pressure or what we also call osmotic pressure photoreceptors these are receptors in our eyes that allow us to see what's now let me just say every different type of neuron in our body have one job and one job only so for instance the photo neurons the photoreceptors in our eyes help us to see light but they certainly don't allow us to smell anything okay and the chemo receptors in our nose help us the smell thing but they don't feel pain you this one type information every neuron has one job it perceives one kind of information and that's it okay so you need to know they don't do this multiple types of jobs in the body I thought these are really interesting so I put it in here we don't have this but snakes have infrared photoreceptors that means they can see you in the dark turn so be really careful in behind it you might not be able to see them but they can certainly see you what soon as bees make that we have up here the Mojave dream it is the most venomous state in North America you wanna stay way way way away from that cubby and by the way they're very aggressive snakes so Mojave green has been known to chase people regular rouses you can kind of stand away from them look at them and you know pay existence and they don't care Mojave greens would like to look the bad boys of the desert don't even look at me just get away from me and if you keep looking at me I'm going to chase afternoon and maybe a space they are very very aggressive the high degrees have two different types of venom which makes them worse than other objects the first type of venom paralyzes you and the second type of venom is like Ebola it actually starts to dissolve your internal organs and so you get bit by Mojave dreams they like call somebody they get me a helicopter now the other weird thing is we don't have any anti-venom for breath nice and light others you have to actually go to Loma Linda to be given in the browser they can see them because they'll be able ones around that paddock which I don't understand every once in a while if you listen to like the country radio station you might hear Loma Linda making announcement on the radio to ask people to go out and start catching rabbits mix again because it's like time they've run out of the anti-venom and there's a bunch of crazies up here you go around they collect rat snakes all over the desert bring them back down below Melinda and they built those snakes and they make your anti-venom from it like so unless you know what you're doing do not listen to that radio stations don't go collecting graphics just not by way of a hobby greens are green leather all about are kind of a lime-green color they fit really nicely under the you know desert green type of pushes and they're hard to be careful thermoreceptors these are receptors that help us to tell differences in temperature and this is one of the things we're going to do is laughs today we're going to figure out the density of your different thermal receptors so we're going to try to see if you have more hot or more cold thermo receptors because the lure of one type of receptor you have the more intensely you feel that temperature so for instance just genetically some people may have more cold receptors than hot receptors and usually if you have a lot of cold receptors you feel cold and template you don't want to live in cold places if you have a lot of heat receptors you feel apart intensely you can't stand on my desert in the Sun okay probably are dreaming about going to some places you know because you don't feel the cold and influence someone else so we're going to do a little test in last day to see which type of receptor you have the most up following our each others we'll talk about these there are the receptors in our ear they help us to pick up that way by the way we on have you type up with some soul food electro receptors electric fields have this so that they can find their girlfriends in the ocean they can detect electrical currents so another one feels giving off electricity they can detect that sharks have something very similar to that they can detect changes in wave patterns in the oceans up to a mile away so when you're kicking and bobbing around and everything you can know that any shark in the area knows that you're there if I don't go out there my brother is he's crazy he's a big-time surfer he's been on the surfing circuit he told me he was surfing not too long ago off the coast of South Africa which is a huge place for a great white shark and I said he was just out there you know waiting for the next really big wave and he felt something hit his foot anyone was a feel you know I didn't think anything of it and a few minutes later he felt a thing come back the other way his other foot and of course being my son brother he didn't get into that he didn't even look down somebody waited for the thing to come back a third time and his foot again and then he decided to look down they said it must've been at least 15 or 20 feet long okay what did you do a lot picked my feet up out of the water cuz you know they're looking at you from underneath and they're thinking you're a field because you got you know all four arms and legs on this board they don't know any better and you said need just praying for that way to cover look fathoms you can get the heck out there so he did talk away he got out but he's cruising to the other time and once I was a huge practical joker so they thought it was just joking and then I guess that sharp enough to come up and they saw the spin and you know everybody else was out there too and I go here what did you do after that well they're probably waiting for about 15 minutes and went back okeydoke my daddy when she was born somebody dropped him on his head we just got right back in 15 minutes later anyway the last type of receptor is a notes inspector and I really want to tell you about this one because this is a pain receptor we have more notes inspector than any kind of sensory neuron in life our body wants to make sure we feel pain why is that apply on 50 keep us alive does that mean for every single facility helps to protect us prevent damage right okay so there is a genetic defect that some children are born without any mental suckers and they cannot feel any pain at all so imagine okay little day you're walking around the corner of the depth and you walk too close and you hit your leg really hard on the corner you know next time to walk further around okay the brain makes that conscious adjustment okay unless you just deflect it does alright and you make that kind of adjustment but these will to família they hurt themselves they hid themselves they pierced and month or whatever they don't feel any pain the brain doesn't know better to make that adjustment I had a family friends that they had a little girl who was born with this very rare disease and at two years of age she had some brothers who were like three and four they not much older than her and they just thought it was really funny that she was running into the garage and so they were egging her on and she's tested backing up and running into the garage door over and over and over again and though she killed herself she didn't know her brother spotted body she thought it was funny she just kept doing it and we also see this problem for us has been people who have leprosy one of the problems with this these it also kills off the nociceptors so these people become very deformed because they don't realize that they're hurting themselves so you know they're using a knife not paying attention then you end up cutting on the finger and they don't even feel the pain you might feel a little something but that's not enough for them to pay attention to what they're doing like for you and me this mint just slice through the skin you're going to stop what you're doing and so they have a lot of deformity again because they can feel what the rest of us feel so we love to be doing a little test with nociceptors today during class too and so that I can watch it all happen sorry I was just thinking it I'm sorry anyway alright so we're going to talk for a little bit about a group of cells that are found focus in central and the peripheral nervous system and these cells are what we would call calipers that they're there to help our neurons matter back in the central nervous system we have more detailed results and we've been down there on these helper cells are all neuroglial cells okay satellite global and we also have I got okay so the first type of neuronal cell we're going to talk about is something called an absolutely after site have two very important jobs job number one it maintains the blood-brain barrier job number two it forms and hold synapses okay so let's talk first about the blood-brain barrier so in this picture here this is Mass Effect and in this picture here this is an exercise okay now astrocytes are always sounds right by blood vessels which is what you see here in red these are pleasant so you can see it very well on the cartoon this is also a blood vessel and the astrocytes have evil legs these little projections that come off of them and other sites in the brain will grab hold of the nearest one vessel and also black grab a hold of the neuron so in yellow this is to represent in neurons now notice in the blood vessel when the ashramites grab a hold of it they wrap around a blood vessel so much you can't even see the blood vessel now the big thing with the neuron they're just kind of sort of hold on to it they don't totally wrap around it the reason of these outsides are wrapping around this blood vessel completely is because they are forming a barrier they're forming a blockade not allowing serve chemicals to leave that blood stream and get into the brain but there's certain things we don't want to actually jump out of the blood and into our central nervous system and the astrocytes have the ability to prevent that the other thing that the answers might also are doing here is they're able to basically suck out remove certain nutrients from blood and then deliver those to the neurons so the answers are not only blocking particular chemicals from getting out of the bloodstream but they're also taking other chemicals from the bloodstream which would be nutrients for our neurons to help people learn a lot it's also kind of like they're nursing the neurons so they're taking chemicals from blood and feeding our neurons so that blood-brain barrier is actually the astrocytes blocking Cannibals from leaving the bloodstream and then abscess by the main kind of been called nurse so they're feeding our neurons it started again we are talking about a neuron and Roosevelt and if you can't figure out what they did not quit in a solitary is dr. harvey rendition of a neuron okay so I'll label it a little bit more later but just get used to it now so neuron wheel cells if we go back to the fetal stage of development when we were first starting to develop a brain and the spinal cord you have a lot of different neurons that are being produced and those neurons have to be able to talk to them and so what the neuronal cell does with all of the little arms was what we call is prototype it will probable the neuron number one and grab a hold around number two and bring them together kind of plug them in so the bacon have a discussion so that they can talk to each other so if we say that is a neuron number one and this is there on the first these information flows in this direction from neuron number one across to draw number two now where these two neurons meet this region here this is what we call the Senate so bland zone astrocytes bring these two neurons together to talk they're talking to each other at the center the small area between there on one and neuron two of an open space here into what we would call the synaptic cleft and on board it will huge but in our body when these two neurons come in our app it's enough that synaptic cleft is very very tiny is really small it's a matter of fact it's been measured from the end of drugs once the beginning of neuron two it is only 10 angstroms so remember how kind angstrom is okay very very small we've been basically that these two neurons are almost touching each other they are so close to each other okay that's the mountain clef is not very big whatsoever now also just so that you know since this first neuron comes before the synapse we call this the pre-synaptic neuron and because the second neuron comes after the set up we're going to refer to it as the post synaptic neuron okay so then as you type continue to do this throughout the brain and the spinal cord so they're taking neuron number 68 and there are number 572 and bring them together so that they can talk to each other and form all these penises now in our brain exercise or enter front for alpha 5 form two types of Vanessa's one type of synapse is what we would call plastic and another type of synapse is what we will call cemented okay the low-tide what's the difference between a plastic synapses and as lamented enough we have one of the terms you're going to use in the medical field is you're going to try to say hey we need to keep as much plasticity in our patient's brain as possible because you want more plastic neurons than cement it so here's plasticity anytime I learn something doesn't matter what I'm learning so maybe I'm going to learn it into it okay maybe I'm going to learn to play the violin right as I learn to play this instrument what's happening in my brain is that my astrocytes are actually moving neurons arrest so that different neurons can start talking to each other that may never have talked to each other before and the more I practice at playing the violin the easier it is for my astrocyte to move these neurons into the appropriate place so that I can improve and the more I improve the more a stroke can be moving neurons around so though I can play better and better if and afters I have the ability to move neurons around in different places those neurons that are being moved those are plastic neurons and we formed plastic ten ounces but plastic synapses may not stay where you put them so I'm practicing this violin and maybe I get really really good at playing the violin maybe I even play like in the orchestra or something and then I'm just sick of it Ottawa says violin anymore I put it into chains I put it away I don't have anything to do with it for the next 20 years and now I'm regretting it and I get violin back out again am I going to be able to play as good as I did 20 years ago now I might remember things I might still be able to play some lot because I did a lot of practicing but I'm not going to be a good the reason is and because over those 20 years I was doing different things and the astrocytes took some of those neurons that were they're all about my music playing and move them to different places because I started doing different things and aspects are the moving neurons if I want to get really good again I've got brain neuron back but now here's the problem sometimes when answers I bring two neurons together they will stay here forever and they will become what call cemented so if you notice for instance riding a bike once you learn how to ride bike you will never forget so if you haven't written the bike for let's say 30 years and then you get on a bicycle to go ride it you can you will be able to you might look a little klutzy but you will be able to still right now that's because once you learn how to ride that light the voucher side while you practicing we're bringing certain arrows together forming certain synapses until they form enough that your brain was able to go okay I got the balancing I understand what's going on let's ride no more training wheels but for whatever reason and nobody really knows how to bring pride which synapses are plastic and can be moved and which synapses are cemented and can never be moved right the bike is all about cemented synapses and so once you learn how to write it so tune up those are always there and they will never be moved and you will know how to ride a bike when you're nine years old now you may not be able to overlook more no hands okay let's just nobody else get on and ride because those synapses are cemented now some of you may have experienced this when you came to school so let's say that you know you graduated high school and then you weight it for several years to come back to college in your first semester you probably thought might be pretty good in high school and then you realize oh we got this okay things that happen and I forget how to study and I forget how to memorize and I forget all this stuff but maybe my second semester it was starting to get better and by the third semester like all the I office there's no problem well what was happening all that time is as you were practicing studying and doing the things you needed to do for school ostracize from Livingston essence again and in our elderly patients one of problems is if you're not constantly utilizing the brain it becomes harder and harder for astrocytes to move within us it becomes more and it leaves much more likely to think like dimensions so the more you have people using their brain I mean even just playing games doing different things reading fun books doesn't matter something besides sitting around watching television all the time okay this will help the keep the brain your plastic more flexible so that it's easier for them to learn and less likely that they're going to have dementia problems any question with this well it's not necessarily completely gone and if you've been playing the sport for let's say 10 15 years and you let off for 4 years you know it's not going to be completely gone but if you've all been playing sport for 2 years and then you didn't create yes probably not hopeful yeah thank you very humble person that study biology for 40 years I mean after four years is done I'm the opportunist maybe people mess about it how lots of memories people you know are not going to know anything well I mean your memories we knew were up cheap stuff email or then oh I remember that I submit so you're talking about childhood memories versus I go to college and then your later I don't remember what I studied implement well there's a couple of things about that first of all childhood memories for the most part if we're talking a healthy childhood there's not a lot of stress and because you don't have a lot of stress and bring your numbers in easily in college you're under tremendous amounts of stress your brain remembers not the more stress you are under the more difficult it is to remember it yeah exactly exactly it's unfortunate but it's true all right the next type of smell is called in my broth yourself microglial cells are phagocytes so their job is to move around the central nervous system and eat up things that don't belong there in tissues listen if you have vision who have a stroke in microglial cell they're going to get rid of all that dead tissue this there and help between up the area maybe there's a virus that somehow gets past the blood-brain barrier the job of my probably hotels to try to kill that virus and it's job is to make sure that the central nervous system keeps us clean as possible one of the thousands of microglial cells may also be carriers of certain viruses into the central nervous because my Prague little cell can actually leave the central nervous system it can get into lecturing pass through that leper a barrier and get into the peripheral nervous system enter around there too so let's say for instance you have a patient who has HIV and this virus is in their system that virus wants to get into to benefit so get into my problem self we then crawl back through the blood-brain barrier into our central nervous system and drop off the virus this is why some not all but some of your AIDS patients may end up with because my probably will sell that the virus is the brain the next type of neuronal cell to called and ependymal cells ependymal cells are only found in the ventricles of the brain and the spinal cord so if you remember we got the lateral ventricles third ventricle fourth ventricle and in the middle of the spine first column so all these aesthetical cells are lining the walls of all these vegetables and you look here on the overhead you can see the cilia on the ependymal film so the ventricles produce cerebrospinal fluid and the job of the intangible self with its Julia is to move this pre-roll endless it has to move around the brain around the final course it's fluid in helping keep the brains and fretwork life but it also has well nutrients it and so the ependymal cells are constantly looking at cilia all in one direction and that it's the SS is flowing around the brain or spinal cord in one direction and it's providing nutrients to the central nervous okay now some type of things can get into the turbofire fluid like viruses bacteria something like meningitis and really funk it up get it really sick and it doesn't slow well the cilia can't be hard enough to get it moving and this can cause considering death even kill your patient all the shotgun drove by a legal general type reduce Milan and they made a lot of Milan they make enough Milan to cover at least 60 neurons obese Babolat so in this overhead this will sell here that kind of sorta looks like an octopus this is an elite identified and notice the bundle of cells underneath this oligodendrocytes these are neurons so these will look a benefit to move and they kind of crawl up and down these bundles of neurons and they're constantly looking to see if any of the Marlon has you know kind of torn off or been scraped away and they put more myelin back on and repair it so they're constantly making sure that insulation is nice and fit over top of all these neurons this is in yellow also an oligo dendrite site and in red these are all the neurons that are around it that it is produced in Milan for and keeping it inflated okay so in the peripheral nervous system we have two types of neuronal cells the first type of s talked about in the satellite cell and this is going to be really simple because there's still not sure what the heck is that will I tell them the next cow is the Schwann cell and like the oligodendrocytes the Schwann cell produces myelin but it doesn't produce very much Milan okay so notice in this overhead right here this is Milan right here from Schwalm self and then here is a little bit more Milan from Aswan self so all these little white pieces here that's on this axon this is all Milan from schlongs oh that's not very much Milan what the Schwann cell does is to grab a hold of the neuron and then start making myelin that wraps around and around and around and around so that you kind of have like this sort of you know you have seen a jelly roll that could have done it that wraps around around anyway the line will go round round round round this Shanta but there's only a small amount of Milan so how to have multiple chuan belts to cover this neuron not like your legal densified that have enough flour and cover 60 neurons the Schwann cell can't even couples