there's a separate record okay so this is our introduction to the urinary system chapter um trying to remember what chapter it is chapter 26 I believe so and uh so uh unlike the digestive system you can see that the urinary system in terms of number of organs is so much simpler so uh let's get started on our look want to share the screen I think it's it's in the email section so i' have to open up the email for that yeah okay slide two three four there we go let's hide the email you can see this better is this large enough for you to see or I could stretch it a little bit is that large enough to see yeah I can see it okay all right there really isn't a whole lot of detail you need to know I mean basically what we're doing is we're looking at the urinary system so obviously we start off the urinary system by talking about function okay so what is the urinary system do and in terms of function I think most of us know the main functions of the urinary system anyone getting rid of wastes yeah getting rid of wastes I'm going to add filtering the blood to that okay filtering the blood and getting rid of metabolic waste okay that's what we're trying to get rid of we're trying trying to get rid of metabolic wastes and what do we mean by metabolic wastes hold on a moment see a couple chats in the room okay that I read that I read okay can't read the chat don't forget to record I I think I did record okay that's okay all right so uh to get rid of waste and when we saying metabolic waste what kind of metabolic waste are there unabsorbed nutrients no no no no no no no no we're still doing this one okay filtering blood and getting rid of metabolic waste what would you consider a metab iic waste ah sounds like I've just asked stumper question all right I'll I'll describe it metabolic wastes are wastes that are generated by the cells okay the cell metabolism so I think what you were telling me is where this these Wast might come from so go ahead start that conversation again from and absorb nutrients all right when your cells absorb nutrients what might it do with those cells oh those nutrients well in the chapter on respiration we found out that sometimes the nutrients are used for energy correct and so you're going to have carbon dioxide as a metabolic waste you're going to have excess water as a metabolic wastes you can have excess salts and ions as a metabolic waste when you eat too many salty foods kidneys have to get rid of it things like that and of course one type of metabolic waste that's almost exclusively almost exclusively the job of the kidneys is Ura a nitrogenous waste let me see if I spell it right nitrogenous waste okay and these nitrogenous wastes all come from the metabolic of proteins so when your proteins are metabolized what does that mean well your body releases a hormone it goes into your bloodstream doesn't stay there forever eventually it gets broken down usually by the liver and when it breaks down these proteins it releases the nitrogen part of the protein into the blood and the main form of nitrogenous waste we produce is something called Ura Ura obviously is the main component of waste in urine which is the waste product we're going to be eventually making all right you also have nitrogenous waste in the form of ammonia but we don't produce much ammonia in our cells and if we do we convert it to Ura anyway because it's it's just a little too poisonous for us all right now fish when they produce nitrogenous waste fish can produce ammonia anybody um have a a fish tank at home knows that one of the test kits that you use for testing the clarity and and and the cleanliness of the water is is the ammonia test all right and you want to make sure that uh you know the the the the activated charcoal is doing its job absorbing most of the ammonia out of the water right so ammonia is another nitrogenous waste but that nitrogenous waste is too poisonous for us to produce all right so we don't produce it in our blood birds not Birds things like an earthworm might produce it um obviously amoeba um um things that you know and fish fish that live in water you know they have a lot of water to flush out the ammonia so it's not a big problem when land creatures evolved starting with like something like an earthworm or amphibians and and reptiles and and mammals obviously there was a need to conserve water and so to conserve water our bodies discovered a way of saving some of the Water by making Ura as a waste which is a little bit less poisonous but it's still soluble the third nitrogenous waste if you're making a list nitrogenous waste ammonia very poisonous water soluble we don't produce much of it uh Ura main nitrogenous waste humans produce okay and and uric acid is the third one okay uric acid is almost like a a very large molecule it's almost like a crystalline form of nitrogenous waste and some of you might know this already you don't want your body to produce a lot of uric acid because it could cause problems in your circulation what is that condition called where people get severe pain usually in their extremities due to too much uric acid one more time gout it's called gout yeah gout when people get gout usually older people will have pain in their ankles and feet and their extremities sometimes the tips of the toes are so sensitive that the sheets can't even touch their toes and they're in this pain and they're constantly taking some kind of painkiller to relieve it and they find out that their blood is high in uric acid they used to call gout the rich man's disease because they claim uric acid builds up with the intake of two too much protein people are eating meat and big portions of steak every day so from animal protein you build up and you make too much uric acid not good because it can cause gout all right but what all what those three things have in common is that they all come from the breakdown of proteins all right so sometimes you know they they they they suggest to cut down on your portions of meat that you would uh eat during a meal okay well anyway your kidney's job is to get rid of these metabolic wastes okay so filter the blood and get rid of these metabolic wastes to keep the blood clean that I'm glad it happened there you know what let me and that would lead to number two on the list and that would be the second function the kidneys and the fun second function is while it's filtering out the waist it also helps to to maintain blood chemistry by balancing the blood pH asmatic pressure and volume let's put volume as water balance and indirectly you know that see you can really relate to the urinary system by your own behaviors or habits or whatever may be some of you know when you drink a lot of water or you drink a lot of some beverage of choice whatever it may be there always seems to be the need to go to the bathroom soon after whether you're drinking a lot of Iced Teas or you're drinking a lot of alcoholic beverages you're having a party and whatever it may be and you know if you ever go to you know different places different clubs bars scenes or whatever it may be uh yeah there's usually a pretty long line at the toward the middle of the night where everybody's online using the restrooms and if the restrooms cannot handle the volume of people of that particular whatever facility uh align builds up all right so it seems like when you do take in a lot of beverages then there's a need to go to the bathroom more often your kidneys are trying to keep your liquid balanced okay so you drink all that excess beverage and your your kidneys immediately try to filter it out of the blood because your blood volume is increasing okay another thing that's on the list is indirectly related to the urinary system remember the kidneys produce something called erro portin yeah okay and the arthop portin is the hormone that controls what red blood cell production Y in your bone marrow so it's it's it's funny how like it's almost like the kidneys have like a a part-time job while it's cleaning your blood while it's keeping your blood clean while it's getting rid of waste while it's balancing blood chemistry and blood volume and all that it's also saying oh by the way I've got to also produce a Ral poete and I've got to got to produce a hormone that actually helps to make more red blood cells to keep the blood and the body healthy because red blood cells wear out after 120 days so it's the kidneys that actually that actually do that all right the kidneys also produce a hormone called calcitrol for vitamin D production okay but that's just another little SEL that the kidneys do but those top three things okay the top two actually are the main functions of your kidneys in balancing blood chemistry keeping the waist out and as somebody said before you know to to to get rid of waste as being the main th parts of the kidneys okay so that's the a section that's the that's the the function part all right now now in the outline they also talk about other organs of excretion and the other organs of excretion are other organs that also get rid of waste but not as intense as the role of your kidneys for example we already know you have lungs that gets rid of the carbon dioxide it also gets rid of excess water in the form of the vapor that comes out of your lungs and your lungs also believe it or not and and you may have mixed feelings on this but your lungs also help to excrete alcohol that's in your blood and that's why Al alcohol is on your breath if you drink alcoholic beverages alcohol actually permeates your alveoli so when you're taking a breath and lier test or whenever somebody feel tastes or smells alcohol on your breath it's not on your breath because you know you drank the alcohol and it polluted your tongue or your oral cavity no no the alcohol on your breath is actually coming from within your lungs you know I remember a long time ago you know uh one of the students in class said something I I was mentioning this about a breathalyzer test and um and he said oh there's a way you can beat a breathalyzer test and of course everybody in the class went yeah and apparently he claims and I don't know how true this is but he claims that you know even though you have alcohol coming out of your lungs from your bloodstream on your breast he said if you I I if you chew on Peanuts apparently the the the the the the smell of peanuts the aroma of peanuts like planter peanuts or something like that is apparently so intense that it overshadows the alcohol I don't know if it absorbs the alcohol I have no idea of the chemistry behind it I never did any research to find up follow up on it all right but uh for some reason college level students were very interested in the conversation you know I don't know if it's now every College student's emergency box you know first aid kit and and and Band-Aids and a little bag of Planters peanuts just in case you know but I I I don't know I don't I don't promote that kind of stuff but um but at least now you understand the science behind a breathalyzer so when they say breathe into this device and they can tell what's the concentration of alcohol in your blood now you know why because it's coming from your bloodstream through your Alvi into your breath okay so lungs is on the list of of organs that act like you know assistance to the kidneys for filtering waste but the lungs are mostly for carbon dioxide and not too many other things uh your skin is another one you could put on the list your skin your sudoriferous glands remember those your sweat glands okay in your sweat there's certain waste products so while your sweat is trying to cool off your body in that Sweat There is there's water of course uh there's also salts in your sweat and believe it or not there's actually some urea in your sweat this might seem a little distasteful but you yeah the chemistry of UR of of sweat is diluted urine uh and um and so uh just you know just be aware of that okay so your skin helps while it's cooling off your body as a thermo regulator um uh your skin is also releasing some waste and of course we know there's a major organ that's constantly trying to keep your blood clean and that's your liver okay but one thing interesting about the liver is the liver filters a lot of things out of your blood stores some of it away but it doesn't actually have a release to the outside environment I mean it could dump some things into the digestive tract but it usually doesn't have even a connection to that directly so your liver will will metabolize certain things in your blood and then it's sends it to the kidneys for the actual excretion like for example metabolizing proteins as I mentioned before so when there's proteins that are not needed anymore in your blood enzymes hormones that have been used already your liver will filter them out break down the proteins and is a a fancy word that the liver does okay liver de amones the excess [Music] proteins into Ura okay so it actually chops off the nitrogen that's what de amones means de amones it means it takes the amino group off the protein and uses the rest for energy could actually store the rest of it all right so imagine a protein molecule has nitrogen and and all the liver does it chops off the nitrogen and then reuses the rest of it to make glucose to store away his fat or whatever may be so the liver is always storing away something but for some reason the liver just doesn't like the nitrogen part and so that's the part it chops off to make uh Ura um okay uh question yes would would your eyes be considered ex an excretion because of Tears yeah you know what I I I never put that one on the list uh but yeah iology so that's all I think about yeah yeah uh yeah the components of tears I mean uh I I I I would imagine that the comp a lot of tiar testing of like what's in your teers how many you produce stuff like that so I don't know okay and what components are found in tears I mean there's salt there's water other things I don't know okay other things I don't know okay because I was just now I'm curious to find out you know I'm sure there's going to be low levels of Ura in in in tears as well you know uh but uh you know the main purpose of course of your tears is to keep your eyes moistened and uh keep everything lubricated but uh you know since these secretions are generated by fluids from the blood anything is possible in terms of getting it there as well um yeah I'm I'm I'm GNA write that down I got to check into that my curiosity up okay so uh so much for the organs of excretion those are those are the main ones that that are there and and possibly tears as well um so um and um so before we go on to the actual structure and function of these uh things here um just understand that's That's the basis of your urinary system okay now what does the urinary system consists of so if you're going to start uh you know a section on B organs of the urinary system or whatever it may be we start off with obviously the kidneys okay okay so there's your kidneys right there so uh I'm almost afraid to click but we'll we'll give it a try ah there we go my fear was justified okay so on this side here talk about B organs of the urinary system and we'll start with number one to this okay of course you have two okay they are paired uh their location is odd in a way okay they're located towards the back of your abdominal cavity behind the peritoneum okay so there's a word for that and you're going to see it in the next slide but I'm going to mention the word now okay it's located behind the peritoneum and so they're located this is the word they use retr peronal they use that as a as a I guess an adverb for describing their location retro meaning behind peronally or they're retr peronally located maybe I should swap those words and it would probably make more sense okay so they retr par perally located and again next to that put what does that mean it means it's behind the perian it's not part of the digestive organ all right now the the only analogy I can use to describe that would be if you took a garbage pal and you lined it with a plastic trash can liner and you put garbage in it that would be the abdominal cavity that's where your digestive organs are where are your kidneys your kidneys are between the bag and the wall of the garbage pale I don't know if you can picture that okay all right it's between the bag and and and the wall of the garbage P so it's outside the peritoneum it's behind it okay um okay the the kidneys uh are also partly protected okay there they are part ly protected by your uh vertebral ribs uh your F what do they call those the floating ribs okay and that's why if you look right in that picture right there that's why kidney punches and boxing became illegal because when somebody took a blow to their back the those bones right there notice they're not connected to cartilage and so they can actually puncture the kidney and cause severe hemorrhaging all right now why would that be a problem the next fact the kidneys receive 20% of the cardiac output so every time the heart beats 20% of the blood goes right to the kidneys and of course you know the names via the renal arteries okay so there's a lot of blood going to the kidneys so if the kidney gets damaged they're going to bleed and they're going to cor severe drop in blood pressure all right there's been chances there's been situations where in the old days of Bo ing somebody would get a big punch in the back on a rib crack a rib the blood would be pouring into their urinary bladder or their abdominal cavity and then all of a sudden the person will get laded and faint and they be dead before they reach the uh the training room or you know so the so damage to the kidneys are very very fragile in terms of their their ability to Hemorrhage rather quickly if ever if ever you you happen to fall or a child Falls and bangs and you know their back against the edge of a desk or the edge of a table okay and suddenly they get the urge to urinate if there's blood in their urine you should not waste any time you should rush them immediately to the hospital okay because bright red blood in the urine means that the kidney was damaged all right now you do have two kidneys they claim you can survive on one kidney and why is the reason for that last fact about the kidney each kidney has a million filter units called nephrons okay and it turns out that a million nephrons is more than enough to filter your blood effectively so we do have two kidneys so each kidney has a million nephrons in it to filter your blood and that's why kidney donation is possible all right now it would take a lot you know I mean usually you hear very often that you know close siblings somebody has some sort of kidney disease and they need a kidney transplant and usually it's someone in the family that they check for compatible donation you know compatible blood types compatible proteins or whatever it may be to see if there's someone in the family that can donate a kidney to their their their their older brother or or or younger sister or whoever it may be in the family um however you know you know it's a little scary to think you've got two kidneys and you donate one and then what if your kidney gets diseased you know that that that that's a you know that that's a little bit of a risk that you take but uh you know you you you're dealing with you know family or a close friend or whatever it may be uh and you hear this all the time how somebody will donate a kidney to a child or a sibling or somebody in the family but now you know why it's possible because the kidneys are very effective as long as they're healthy in in keeping the blood clean okay and we're going to get into the details of that when we do the the anatomy of uh of of the urinary system now number two on the list once the kidneys do that job once the kidneys filter the blood get rid of all the waste they concentrate the waste in the form of urine okay that's the product that comes out of your kidneys now we have to get that urine out of the body so once we understand the function and the structure of the kidney the rest of the urinary system is part of a urinary tract there we go again a tube a passageway for urine and it begins inside the kidney from the inside of the kidney it enters the ureters okay these are tubes that lead to the urinary ladder and they're not just hollow tubes they're not like little straws that just drain the tubes in okay the tubes that lead to the urinary bladder that carry maybe not carry I'm going to use the word trans this's a difference that transport urine to the urinary ladder by peristalsis so it's not just letting the urine drip into the bladder it's actually pushing the urine into the bladder and as it pushes the urine into the bladder guess what your bladder does it expands then expands and expands and expands eventually it's going to get full sends a message to the brain time to urinate it's very very parallel to to the rectum in the large intestine that once it it stretches it sends a message to the brain and the Brain sends messages down to release that urine all right okay so that's the job of the ERS sending the the the urine into the bladder so obviously your urinary bladder when we look at its structure is going to be designed to store and release urine once full by a process of voiding okay or fancy name you know it's anatomy of physiology there's always a fancy name for things who knew chewing was mastication who knew swallowing was deglutition and now who knew that voiding urine was called MC [Music] TR yeah it's sort of like like it's got that ending like nutrition except it's mition that's how it's pronounced okay sorry just a vocabulary word you have to go to add to your repertoire of of words there okay so the UR and you going to discover that the urinary bladder has very distinctive features that allow it to stretch to store the urine without tearing its insides and everything else okay leaving the urinary bladder is the urethra okay single tube to expel urine outside body okay ready regulated by [Music] internal and external [Music] youal sphincters now if you had a guess based on your knowledge of defecation which of those muscles can you control during potty training external the external ones because the external urethal sphincters come from the same wall of muscle that make up the external anal sphincters okay there's a sheath of skeletal muscle that creates almost like like like a a a diaper of muscle that actually goes through the bottom of your pelvic cavity okay and I don't know if you did this when you did skeletal muscle in 131 but it's called the urogenital diaphragm I don't know if you got that deep into the muscles of the lower abdominal cavity but that's what it is right there okay so those are the main organs of the urinary system okay so let's look at some of the other diagrams any questions on these basic introduction okay now there is a model that actually looks like this where you just have to recognize you know the certain you know structures and things like that but when it comes to the structure of the kidney itself you're going to have a separate model for that okay so let me clear this and go on to the next slide okay okay now this slide is a cross-section in the body the only purpose of this slide is not to memorize anything that's here just be observant of where the kidney is if you look at the kidney let's see if this will stay it did okay here is the kidney okay now I'm afraid to change color I'm sorry okay here is the peronia here is the parium going around the spleen here is the parium going around the abdominal cavity here's some of the perineum going around the stomach here's more parium going around the stomach okay here's a part of the perenium going around the pancreas okay over here maybe it's going around around the liver I have no idea but the partin's all out there the kidney is behind it the kidney is pinned up against the back wall right here and all these digestive organs are in front of it so if you dissected I don't know if you did this in high school if you ever dissected a frog or a fetal pig or something like that if once you dissected that frog uh or fetal pig we open it up and you see the Digest of organs and you take out the stomach and you take out the intestine and you take out the whatever is in the area there you know the liver uh you take out the spleen you take out all these organs and then the cavity is empty and then you look and there's a thin sheath of clear membrane and you peel that away and behind that that's where you find the kidneys so that's where the word um retr peratin Neal comes from and what keeps the kidneys in place is the kidneys are supported by a series of membranes and we'll do that when we do the kidney structure and most likely not tonight okay but probably on Wednesday uh or it'll be in the video on Wednesday but the membranes that support the kidney and keep it in place you could see here has an outer membrane of connective tissue this is called the renal fascia that's on the outside of it and then there's a thin thin layer of fat that cushions the kidneys okay and this is called the Paran nephritic fat it used to be called the adapost capsule but those are two protective sheets on the outside of the kidney okay so you would peel those away they're holding the kidney in place these are the support tissues that hold and and and and um cushion the kidneys okay and and that's what you see there clear that and here is the front view of the urinary system okay there's your two kidneys this is after you take all the digestive organs out and peel away the parium this is what's behind it okay the kidneys have this unusual shape that little indentation that you see in the kidney right there that's known as the hilum yeah just like the lungs had ailum or hus uh the kidney is also have a hilum where there's an entrance way right here as well obviously these are the kidneys the superar renal glands are on top there's the ERS and there's the bladder urinary bladder sitting in the lower portion of the pelvic cavity even the bladder is not part of the peritoneum uh I came up with this word I haven't seen it written in the book but if if the kidneys are retr perianal behind the perianal the bladder would be infra peronal it's actually underneath the perianal all right so that is our basic urinary system okay right it's showing you the left and right and it's showing you like the stuff that we learned already things like renal arteries renal veins and some of the other things in here that's circulatory that's not part of the system we need to know just showing you in relationship to everything there's your abdominal descending aorta there is your inferior venne Caba and 20% of the blood goes into these renal arteries and veins okay so here is the kidney and we're going to use this as a model for understanding basic kidney structure and you can see it's not overwhelming but the to understand the function of the kidney you have to know the basic structures that are here okay and there's a model of a kidney that looks just like this Fila all right so real quick just a overview of the kidney structure if we were in a regular lecture I would tell everybody right now open up your notebook and you could do this now if you'd like to draw your own kidney in your notebook so that way you'll understand it better all right and so you start off with a like a a backward C so if you're drawing it you make something that looks like this okay all right and if you want to label it with a number okay so what is this what did you just draw and the answer is right here you just drew the fibers capsule you'll actually understand that's a whole lot better if you do it this way okay and hopefully we'll get lucky and everything will stay together okay now watch what I'm about to draw next ready I'm going to have the inside now and the inside's going to be like a bunch of Hills so you can draw as many Hills as you want okay doesn't matter as long as you make it look like a nice fat seed okay we draw those little bumps four three five okay now this empty space that you just drew here okay you might not want to make an arrow on yours okay but I'm I'm making an arrow so you can see what I'm talking about that empty space there is something called the renal sinus okay your kidney is actually Hollow in the middle I sometimes compare it to almost like a like like a glove if You' like okay but it's empty right there that's the Ral sinus an empty spot all right now I know some of you are looking at this picture of the kidney on the left and go what does it mean empty spot I see all these things in the way well unfortunately there's things in the way of that empty spot but we'll we'll deal with it now what's in the kidney itself well if you notice the kidney's broken up into two zones so there's an outer zone so if you want to draw a parallel line to that outer line you could do it like starting here just make a thinner outer line that sort of goes parallel to the outer line closer to the outer line than the Inner Line go like that okay so it's like you you drew an OU a layer see here it's in a lighter color okay that lighter color that's out there looks like a lighter pink or whatever very light colored okay that could be our number three and that outer layer is the renal cortex that's our number three the renal cortex in a real kidney would be bright red the renal cortex is where filtration takes takes place so in other words the renal cortex is where you find most of those million of nephrons okay so that's the functional part of the kidney and that's the part you don't want to damage because there's so many capillaries in there you'd start bleeding if your kidney got punched or hurt Okay so the renal cortex I I said maybe four things about it so let me say it again you check your notes okay it's the functional part of the kidney I said okay it's where filtration takes place it's where you find most of your nephrons all three of those characteristics sort of overlap with one another because that's what makes it the functional part and the fourth thing I said about it is in a normal kidney this would be a very red area because there's so many blood vessels in there so what is this other layer here well this other layer that's a little deeper is layer number four and that's the renal medulla now we've got a little problem with the renal medulla because the renal medulla is made up of a lot of substructures okay now I don't expect you to be artist so we're going to make it a mock of what the renal medulla has in it so in the renal medulla we'll we'll list it as 4 a 4 B 4C or whatever okay first thing do you notice it there were these little fanlike structure in here so every time you drew a little bump turn it into a little fan like this I should have had a bump over here so I'm just going to add a bump over there okay there's a bump here and there's a bump here so on my drawing I made one two three I made four four bumps just to make it look even okay on the drawing in the book there's one two three four five six there's seven in that one okay so what are those little triangular bumps okay we're going to call those triangular bumps for a okay and those are called renal pyramids okay those are the renal pyramids okay not going to tell you anything about them right now okay those are the Reena pyramids in between the pyramids this is going to make sense now in between the pyramids think of it as like holding up the pyramids in between the pyramids are spaces okay these spaces are usually filled with blood vessels okay so we're going to call those spaces in between 4 B those are renal columns those are the spaces between 4 and at the tip of every one of those renal pyramids there's a little round area right here at the tip and so the tips of the pyramids we're going to make 4 C and those are known as renal Pilla and believe it or not that's it those are the structures of a kidney the functional parts are all in there okay all right now I'm going to stop right here but before I go let me just explain quickly so what's the rest of the stuff here oh well when the kidney does its job what's it going to do it's going to make urine right and these little pyramids are actually made up of tubes that are actually going to cause urine to be made and they're carrying the urine right to that renal papilla those tips and so from these tips you can have urine dripping out well obviously if the kidney is going to have drips of urine leaking out what would you need to do with that urine you would have to catch it and make sure you drain it out of the kidneys the rest of the stuff that you see in here are part of your urinary tract and so the rest of this stuff in here is actually your collection devices for your urinary tract they're like funnels so sure enough underneath I really want to switch color to Yellow I'm almost afraid try let's see underneath this pyramid there's a little funnel underneath this pyramid there's a little funnel underneath this pyramid there's a little funnel underneath this pyramid there's a little funnel and eventually the little funnels joined together to make a bigger funnel and ultimately all the funnels are going to join in to make one gigantic funnel that's going to leave so do you notice that the renal sinus is filled up with all these funnels so it's like these funnels here are collecting the urine and allowing the urine to go to the urinary bladder okay what you're going to see in the models on Wednesday Wednesday or in Wednesday's video is that there's a very logic sequence to these you just know them in order the small funnels are called the minor calics when they join together they become a major calic okay so these are all the funnels and then the major CX is join right here where they make the big total funnel and they call that the renal pelvis and then the renal pelvis leaves the kidney yes through the hilum remember that zone is the hilum all right and then once it leaves the kidney the the the the kidney through the through the hilum it now becomes the urer and you know the rest from the urer it goes to the bladder from the bladder it goes to the urethra and it goes out of the body okay so that's what we've got going on here in the kidney four main structures four main structures one two 34 to understand the kidney and then three substructures all part of the medulla okay and then the rest of this is just hollow tubes and maybe now you have an appreciation for the fact that urinary tract infections can be very dangerous because if you have a urinary tract infection in your bladder it can travel up up up and actually affect your kidneys which is something you don't want okay anyway I'm going to stop right there and and let see where am I okay so now that we've gone over the main parts of the urinary system okay so we we've seen the main parts that include the fibrous capsule number one underneath that is the renal C Tex where all the nephrons are located and filtration takes place the renom medulla and of course number two actually was our pointing out of the renal sinus which is that empty place the rest of the tubes that you see in here are actually part of we mentioned before the urinary track so let's Trace over the urinary tract and have a better understanding urine's going to drip from the renal Papa that's at the end of each of the pyramids remember so we had the the pyramids listed before and we had the pyramids as being all part of the the uh the Reno medulla the pyramids were these little fanlike structures made up of lots and lots of tubes that are draining urine okay in between the pyramids are the renal columns that's where the passage of blood vessels are that we'll speak of later and the tip the very very tip of each pyramid that is right here or right here or right here okay every Pyramid has its own little tip there are little holes in the tip and the little holes that are in the tip are represented by the area of the renal Pilla okay so I ended the last part of the video by saying so we're imagining and I took the risk and I changed color okay we're imagining that urine is dripping out of these pyramids and now you can follow what is catching those drips of urine okay first is the pyramid or I'm sorry the funnel underneath each pyramid the funnel underneath each pyramid okay and I'm just color them in lightly in yellow okay every Pyramid has one okay and what every Pyramid has is a minor calx okay that's the first place urine drains into when two of these minor Cales join Watch How I color this in when these two join together that's what creates a major callx remember all these are the same they're all Hollow they're inside your kidney drainage funnels that are capturing the urine so the urine goes from a minor calus into a major calx here's a minor and a minor so right here where I'm coloring in yellow would be the area of a major CX notice I've drawn a few major calluses here this major callx join three minor calluses by the way callic plural is cises you drop the X and you put CES so that's you know this is a minor calx that's a minor calx all of these are minor kaces that's how it's pronounced okay so what happens to these major calluses the major calluses all join in a common place okay so where all the major calluses join together you see I left that space empty okay the space where they all join together is called the renal pelvis so again if you're following the order of the urine after it drips out of the renal pillar it goes from the minor calx into the major calic into the renal pelvis now I don't want to Circle this in yellow because it's sort of like not part of the structure it's an area Okay so for the renal pelvis which is all this for the renal pelvis to carry the urine out it's got to go through an archway okay and that Archway I'm afraid to change color because I might lose the screen but that Archway would be the hilum okay remember the hilum on the lung was the entrance and exit to the lung well the hilum is the entrance or the renal hilum I guess is is the entrance or exit to the kidney so how does blood get into the kidney renal artery through the hilum how does blood get out of the kidney renal vein through the hilum how does urine get out of the kidney well it's in the renal pelvis and it's going to go in the urer but to get to the urer it has to pass through this area right here so whenever you draw a kidney when you draw a kidney like this this indentation right there the indentation would be the hilum because everything is coming out of that hilum the tubes the blood vessels Etc everything's coming out there the the rest of the kidney is basically free floating okay and if you remember from part one the outer membrane is the fibrous capsule but remember it's covered by two other layers what's holding the kidney in place remember there was an [Music] outer renal fascia that the membrane on the outside and underneath the renal fascia was something weird called the per nephritic fat it's like a layer of cushiony fat underneath it so these are the two layers that protect and hold hold the kidney in place so what is the true visceral layer of the kidney and if you're thinking fibrous capsule you're right the actual true visceral layer of the kidney is the fibrous capsule these really wouldn't be considered parietal because there's no cavity these are just superficial protective supportive membranes of the kidney okay so where are we at this point we've got urine that's collected in the minor calx into the major calx into the renal pelvis then dumps out through the hilum into the urer so the urer would be number four and this is where peristalsis is going to start and peristalsis takes place and pushes the urine toward the urinary bladder the structure of the urer is very much like the esophagus there's actually smooth muscle layers circular and longitudinal muscles that actually generate the the peristaltic force that pushes the urine in the bladder to make the bladder distend and fill up with urine okay let's take a look at that okay in the next slide there's just a cadabra picture of a kidney uh you could look at it but it doesn't really give you much of an appreciation of a real kidney but you could see cortex on the outside pyramids are the dark areas The Columns are in between between okay there you see some of the kaces and you see the urer trying to leave the area notice whenever they draw the highum they always make it a ring okay because it's an area question okay fibrous capsule of course is on the outside and each of these pyramids have that little pillar at the end but you can't see it in the cabber and I won't be using that okay now what about blood vessels obviously the kidneys receiving 20% of your cardiac output okay has to include blood vessels for the most part the names of the blood vessels are just again a list that you have to put in order so again let's take a look and we'll Circle the names and number them okay I think everybody knows where we're going to start and that's right here bringing in 20% of the cardiac output with every bead of the heart 20% of the blood is going here to be cleaned we start off with the renal artery the renal artery brings blood into the kidney through that area known as the hilum right here that area it's like the entrance way and soon as the renal artery goes in it begins to split up into pieces okay that would be number two the segmental artery now I'm ignoring this little Branch here because this Branch here has nothing to do with the kidney look at the name okay yeah that that's sort of like a a a side branch that's going to the Super renal gland that's way up here someplace remember okay it's up here so that's going to be heading up there okay but for the kidney blood goes in and it branches into these segmental arteries segmental arteries are in the area of the sinus they're branching in and eventually they go right in between the pyramids when they bring the blood up between the pyramids number three these are the inter low bar arteries okay these are the inter lobar arteries and these interlobar arteries that's their that's their location they're in between the pyramids they're traveling through the renal columns so if you write that down that's where you find them they're located in the renal columns now again you follow this like a road when it gets to the end of the column and it approaches the cortex notice how it curves to the left or curves to the right that curve gives its own name the curved blood vessels that you see there is number four and they gave those blood vessels a logical name because they're Mak a curve they call them aru those are the aru arteries they make an arc okay so those are the aru arteries that curve over the pyramids but we need to get blood into the cortex so notice there are these Thin Red vessels all over the place Thin Red vessels that come off of the AR aru and send the blood into the cortex so if you had a name an artery that goes out and radiates out to deliver blood to the cortex to be filtered you would call it number five the cortical radiant arteries now in the book they're also known as [Music] inter [Music] low arteries but students were often getting interlobular arteries mixed up with inter to low bar arteries all right but these are the smaller ones you can use either term for for me but this is the one that the book is now focusing on cortical radiant arteries sounds like it's describing it better now where are they they're in the cortex what are they doing they're radiating out like the Rays of the Sun and that's not the last blood vessel there other blood vessels in there that are microscopic that actually bring the blood to the nephrons but we're only looking at the large vessels in this diagram okay so once the blood is filtered you obviously need to take the blood out and return it to circulation now notice the arteries are all red because the kidney is an organ that's going to be using up the oxygen to do its job to stay alive so even though it's cleaning up the blood it's also using up the oxygen so the returning blood is kind of weird it's clean of all its metabolic wastes but it's filled with carbon dioxide now that the lungs have to take care of later but let's just deal with what the kidney is doing so the kidney cleans the blood and now the cleansed blood the filtered blood is leaving with the carbon dioxide through an exit of vessels now watch the names of these exits and vessels the vessels that brought the blood into the cortex were cortical radiant arteries so what are these blue ones that are taking the blood away sure enough they are cortical radiant veins now in between in between five and six the blood went to the nephrons remember they had to be cleaned so the nephrons were the little in between stop off between five and six but this is just exiting blood so the exiting cleansed blood after going through the nephrons is the cortical radian veins and I think you're ahead of me now because you see what you could see it the cortical radiant veins are going to merge into these curved blue vessels and that would be seven those are the aru veins aru because they're curved and the aru veins are going to go down the columns well if the red ones going up were into low bar arteries then the blue ones coming down must be yes into lowbar veins and what are these interlobar veins doing well if you notice these interlobar veins are all going right into this spot right here so the inoar veins go right into the renal vein number nine now I know some of you were saying gee what about segmental veins you skipped one professor and the reason why you don't see segmental veins is for a very simple reason the anatomists of the world dissected kidneys and for some reason they have agreed that there are no segmental veins they don't see segmental veins now I think the problem is the artist has a trouble drawing this without showing segmental veins all right but you just have to make a mental note that when it comes to veins and arteries they're all in parallel except for segmental veins there are no segmental veins anatomically in a kidney no matter what the model shows there is no name there's no segmental vein so that's the order of blood flow in a kidney and again remember we're dealing with 20% of the cardiac output blood is going to the kidney to be filtered to be cleansed of all the impurities all right and so excess U Ura salts ions pH adjustment anything that's not needed the kidneys will do its best to try to filter it out of the blood okay all right now let's get past the blood vessels and look what's beyond okay well as I said if you zoom in and look really really close those cortical radiant veins are sending blood into your nephrons so what are these small units it's called nephrons well the first thing you to notice in this diagram right here is that the nephrons are drawn in and there's two main types of nephrons so in your notes if you're making a massive thing called nephrons maybe you're making it oh letter C or letter D in your notes or whatever okay the structure of a nephron what are nephrons well the first thing you write down is what nephrons are there are the microscopic filter units of the kidney H interesting just like the Alvi with a microscopic units of your lungs and then you had Villi those microscopic well they weren't really microscopic those little finger-like structures that were in your intestine for absorbing food so anytime you trying to get something in or out of the blood you have these little microscopic units so again alvioli in the lungs Villi in the intestine now we want to clean the blood so we have these nephrons okay so these are the filter units of the kidneys nephrons okay and the first thing you see here is there are two types okay the two types that you see are based on structure alone there are short ones that are in the cortex so because they're short and they're in the the cortex they just have a logical name they're called cortical nephrons okay they're the short ones okay and most of the nephrons are cortical nephrons because they're in the cortex okay so the most numerous um I'm going to throw a number out there let let's just say 802 to 85% of all nephrons okay those are the cortical nephrons those are the short ones but the ones near the bottom of the cortex they have this long long Loop that goes into the medulla because these little nephrons here are near the bottom they only represent Maybe 15 to 20% of the nephrons they're a lower amount and because they're underneath okay they have a slightly different name and I joke so just put up with my dryness and my joke okay these long nephrons that are down near the bottom of the CeX that go into the medulla have a very complicated name or sounds like a comp complicated name but it's nothing to worry about nothing to worry about folks it's just the medary nephron I'm sorry if that's making you moan okay it's jua medary Nephron and that's what they call it J the medary nefron okay they are the nephrons that are long and they pass [Music] through art of the renal medulla okay and as I mentioned okay they represent about 15 to 20% of the nephrons okay but they're all doing the same thing they're all basically have the same basic parts we're going to look at the details of the parts in a moment okay but that's where the nephrons are remember most of the nephrons are up here a few parts of the nephrons actually dip into the the medulla okay but one thing you got to find out that what these nephrons do is remember their job okay they're going to filter the blood okay balance blood chemistry and produce urine for excretion okay and the what they do with those those the urine is the urine is going to go through the pyramids through collecting ducts there's a whole bunch of tubes the pyramids are actually made up of nothing but collecting ducts and so you could see this pyramid here try to imagine that in this pyramid there are tubes didn't mean to do do that okay just yet okay now okay there are tubes in here and these tubes are collecting urine and that wasn't supposed to be blue okay collecting urine there we go and these tubes are collecting urine and collecting urine and collecting urine and collecting [Music] urine so this is not really a fan this is actually a thre diim dimensional structure like a pyramid and it's filled with these straws it's filled with these tubes that are sending the urine as you may recall right here right into the minor CX as it drips through the renal papilla right there now they didn't label it but there's the real Papa right at the tip remember the tip the tip of each Pyramid has that renal Papa renal where the urine is dripping so the pyramid itself is nothing but tubes that are draining the urine right down there okay so let's take a look at the structure of the know uh of the nefron structure so we get a better idea of what these uh how these structures are composed okay all right this is just a review of the blood flow so again if you look at the blood flow if you want to review it real quick okay I'll just draw little circles around the renal artery segmental arteries into lowbar arteries aru arteries and cortical and cortical radiant arteries are bringing the blood to the nephrons okay and then the cortical radiant veins are leaving aru veins leaving into lowbar veins leaving going right into the renal vein because remember there is no segmental veins okay so this doesn't go here there's no segmental veins in here the rest of these blood vessels here the rest of these blood vessels here are the blood vessels of the Nephron so if you want to make a separate list blood vessels of the Nephron why don't we wait until we see the nefron and we'll get to look at that and we'll see it in detail instead of just writing down words so let's do that right now see when you look at a nephron the blood vessels that actually go into in there for are not shown here we're only seeing a couple all right but I'm going to go over them with you right now so that way you get them out of the way so in your notes if you wish you can make a list and say blood vessels of the nefron okay number one what's the blood vessel that brings the blood into the nefron well if you look at this diagram there is one and it's labeled right here I'm trying to draw a circle around it and it's not giving me a circle yeah it's called the afferent arterial okay it's the in Inc coming blood okay and the incoming blood is going right into the part of the Nephron known as the renal core pusle but it brings blood into the nefron then the blood is broken up into a bowl of capillaries okay that would be number two the glow marrows and these are not just a ball of any kind of capillaries I'm going to fix that these are a ball of Fon strated capillaries and you remember fenon strated capillaries as being those capillaries that have little holes in them yes because these are the capillaries that going to allow the blood to filter out there's going to be massive filtration going on in here so the AER arterial just brings the blood in but the glomus glomerulus is a ball of fenestrated capillaries that allow massive blood filtration take place in the renal Cor pusle and that's what's going on in the renal cor pusle now once all that blood is filtered in the renal cor pusle then the blood can leave and if you haven't figured it out already the blood leaving would be the efferent arterial and this would be the outgoing blood from the renal cor pusle so that's the main blood vessels that go into the functional part of the kidney the nephron I should say where the filtration takes place but we're not done yet you see once the filtration takes place the blood has to reabsorb what it wants to take back from the filtration process so watch what I'm about to draw when the blood leaves the epher arterial the blood has two destinations possible part of the blood is going to hang around here it's going to go around these [Music] tubes and around these tubes and around these tubes in a network of capillaries and all these capillaries that go around these tubes here are going to be reabsorbing a lot of useful materials the cap Aries that you saw me just draw right there okay that's one of the destinations of the eent arterial so from the eer arterial it can go into these capillaries up here okay and those capillaries up there I guess we could make number five okay they're called per tubular capillaries because they wrap around the tubes okay parer tubular capillaries okay and we'll talk about their function later but they're mainly for reabsorption of good stuff and possibly secretion we'll talk about that at the end okay but not all the blood is going to go to the peritubal capillaries some of the blood will Branch out and go down here before returning up these blood vessels that are bringing the blood way down here called these long tubes right here number five these are number four up here those long tubes are called the Vasa Rector and so when the lasa recta create these capillaries down here even though these are also peritubular capillaries just to show the difference I call these the vasera capillaries now you're going to see a diagram in the book where they call these capillaries down here peritubular capillaries also but the difference between these capillaries and these capillaries is the fact that these are peritubular capillaries in the Superior part of the nefron and these are the peritubal capillaries of the basor recta so to save you from the confusion I just call the ones on the bottom the vasor Rector capillaries if you want to call them the vaser Rector peritubular capillaries that's fine okay you know either way they're both both a set of capillaries mainly for reabsorption now notice eventually this blood has got to leave and so when the blood does leave you're going to have these vules number six these Veals that are B basically going to carry the blood away from the capillaries and these vels are just exiting vels okay these exiting vels are going to carry the blood too oh well if you haven't figured it out yet what was the name of the blood vessel that brought the blood in to begin with well remember you had the cortical radiant AR AR y bringing the blood in and so to No Surprise on the other side is going to be the cortical radiant vein bringing blood out so those are the blood vessels we already spoke of cortical radiant artery bringing blood in and cortical radiant vein bringing the blood out but look what's in between all these that we mentioned okay so the nephron blood vessels include the afferent arterial bringing blood into it the glomus which is the little bow of capillaries inside where the filtration takes place the efferent arterial which is leaving that's right here and then the epher arterials got two destinations it can either become the peritubular capillaries on the top or it can be the vasor Rector capillaries near the bottom and they're all going to exit through the vules before returning to the cortical [Music] radiant veins that are heading out and then again you could go back and start thinking about where they're going to go into the arcu it that's good practice is to list the other blood vessels on the way out but we're not going to do that right now all right so this is the blood vessels of the Nephron now once you understand the blood vessels of the nefron now we can go back and look at the nephron structural function so let's get the blood vessels out of the way and look at the nefron itself so if you want to create a a a different set of notes now you can write nefron structure and function and we're going to break it down this way if you look here it's as if the notes have already been created for you so let me just elaborate we can make Roman numerals and say phase one what happens first the first thing that happens is you've got glomular filtration happens in the renal cor pusle and if you look at that renal cor pusle it says production of filtrate happens in the renal cor pusle okay high pressure blood enters the glomus and squeezes out over 180 lers per day of filtrate into well let's see what they call it they call it the gloma capsule into the glom capsule okay this is one of those structures that used to have a formal name maybe in high school you might remember they were called Bowman's capsule I'm still used to calling it Bowman's capsule but Bowman's capsule is that purple structure that looks like a catcher Smitt that goes around the glomus okay so that's where the filtrate is captured right there in the renal Cor pusle in Bowman's capsule between you and I if you call that renal cor pusle Bowman's capsule I'll probably say okay all right but be be uh be be clear in what you're looking at Bowman's capsule is the outer portion of the renal core pusle inside the renal cor pusle is the glomerulus the bowl of capillaries so technically the renal core pusle is consist consists of the glomus all of capillaries surrounded by Bowman's capsule so it's a two structure two main structure uh portion of the uh of the nefron okay so that's phase one happening in this part of the uh of the Nephron phase two well if you look at the nefron phase two is going to happen after the filtrate is collected it's going to go through this little tube right here but remember the blood vessels okay I'm not going to draw them completely but remember the efferent arterial blood vessels are going to go back here and try to reabsorb the substances it needs so here is the first portion of the nefron and this will call Roman numeral 2 all right and in Roman numeral 2 we have Roman numeral 2 a okay and I I'll explain in a moment why I'm calling it Roman numeral 2 a Roman numeral 2 a we have what is called reabsorption of water ions and organic nutrients okay this is not any reabsorption this is called o lior reabsorption oblig there a b in there obligatory I think I spelled that right obligatory reabsorption okay and the reason why it's called obligatory reabsorption is because okay this is where well it says up there 80% of the water and 100% of nutrients and needed ions are taken back into the blood obligatory the blood must take the useful stuff back so all useful materials are returned to the bloodstream okay so you've got this obligatory reabsorption that takes place that takes back all the useful stuff so it's kind of interesting how the blood goes into the renal cor pusle and filters everything out everything not just the waist everything everything gets dumped out and then it sends the blood back to the paratubal capillaries to reabsorb all the useful stuff because 180 lers a day is a lot of liquid you only have five l of blood so you can't afford to lose 180 lers of liquid a day all right so you filter 180 lers but 80% of that water and all the nutrients immediately comes back through obligatory reabsorption that's happening in a certain part of the nefron called the proximal convoluted tube okay so let's write that in in the proximal [Music] convoluted tube you okay and that's this part here that's all curled up okay but we're not done you see the filtrate is going to follow this and go down this little Loop make a U turn and go back up again okay so we enter what is called The nefron Loop and look what the nefron loop says it says further reabsorption of water on the descending limb side and both sodium and chloride ions on the ascending limb side so you have additional reabsorption taking place here as well in the nefron loop okay so I'm going to leave a space and write this continues in the nephron loop continued reabsorption okay nothing General most of it's happening in the proximal convoluted tube all right but there's continued reabsorption in the nefron loop and remember blood vessels are down here too to reabsorb the water and the excess ions okay so if you you wanted to you could put A2 a down here as well but then you enter the distal convoluted tubu and in the distal convoluted tubal up here you're going to put a Roman numeral three okay because what happens in the distal luted tubal is something a little different see when the filtrate gets to the distal convoluted tube that's this part of the bend right here notice that this part was called the proximal because it was closer to the cor pusle this is called the distal because it's further away from the cor pusle which what you're going to have here is you're going to have what they call tubular secretion tubular secretion what's going to happen in tubular secretion is the blood will secrete and [Music] remove any unwanted ions to help balance blood pH and chemistry so in other words this is the last chance for the blood to get rid of and secrete any unwanted ions I'm G to add something to that and toxins to balance blood pH in chemistry this is where if there's any any unusual drugs in your blood they'll get filtered out if you're on an antibiotic excess antibiotic will be filtered out if you took Mega doses of Vitamin C this is where it's going to be taken out and yes if you took any illegal drugs or athletes that take steroids this is where your kidneys will take them out and when they go for a urine test or blood test they can find these chemicals in the person's urine okay tubular secretion the blood will secrete and remove any unwanted ions and toxins to help balance blood pH and chemistry before leaving the distal convolu tubul okay so that's the job of the distal convoluted tubul but we're not done we're g to add something to that also if needed additional [Music] faculative reabsorption will take place under the regulation of hormones like the two hormones you learned about that help to reabsorb water and salt under the regulation of hormones like ADH antidiuretic hormone and aldosterone okay that was the hormone from the the super renal gland to help reabsorb salt so you've got those two hormones working together as a team aldosterone tells the kidney to reabsorb more salt remember this is absorption putting it back into the blood so if the blood while it's getting rid of the stuff it doesn't want want through tubular secretion it also has facilitative reabsorption it'll take back little bits and pieces of things it wants also if needed facultative reabsorption will take place under the regulation of those hormones I mentioned ADH and aldosterone I just mentioned aldosterone to reabsorb any salts that the body may need and ADH to reabsorb the water you might say what order well remember in obligatory reabsorption we only absorbed 80% of the water so of the remaining 20% we've got the additional reabsorption so if needed I'm just going to read it again factal T reabsorption will take place under the regulational hormones like ADH and aldosterone to absorb additional water and salts as needed to [Music] maintain blood volume so if you're dehydrated you have more fact rotative reabsorption if you're overly hydrated you don't do Factor ative reabsorption and you urinate a lot more urine okay we will discuss it at a later date but this will indicate whether you produce two different forms of urine if you absorb a lot of water and if you absorb a lot of the salts that means you're going to take all this material back and your urine is going to be very small volume very concentrated it's going to be hypertonic urine okay that's if you have a lot of this reabsorption if you don't reabsorb a lot of the water in salt then your water is going to be large volumes very clear liquid leaving your body a lot of water leaving your body and this is what we call hypotonic urine very dilute large volume okay not very concentrated at all okay that's where your urine appears to be mostly like water okay so it's very dilute let me throw that word in there dilute okay where if it was hypertonic then it was very concentrated okay and that's what happens during the faal of reabsorption okay you might want to call facultative reabsorption a form of reabsorption so maybe you might want to call it 2B okay because this was 2 a so this is the other kind of reabsorption so maybe maybe 2B it doesn't really make a difference okay but what are we done with now that the blood is now balanced with this chemistry it dumped everything out tubular or glomerular filtration it took back what it needed initially obligatory reabsorption then it threw out little stuff that it doesn't need tubular secretion and then depending on your needs of the body are you hydrated or dehydrated is your blood volume high is your blood volume low is your blood pressure high is your blood pressure low you have facilitative reabsorption to finetune the chemistry of your blood and to make sure your blood volume is normal so this is where we control how much you pee because if you drink a lot of liquids hypo tonic urine is going to be coming out of your body if you've dehydrated yourself all day your urine's going to be very dark yellow and you're going to have that hypertonic urine coming out of your body okay what's left well whatever is left in the filtrate it's ready for stage four stage four is collection okay urine is now collected and sent to the minor CX via the collecting ducts that will join the papillary Ducks before it drips out [Music] through the you remember where it's going to drip out of yes the renal Papa at the end of your each of the pyramids okay and that's what you see in these last two things right here okay so here would be Roman numeral four collecting duct and papillary duct now I'm not ignoring it I'll point it out to you right now notice even when the urine is collecting in the collecting duct there'll be a little bit more reabsorption and secretion of ions so even at this point there's still some fine tuning of the blood chemistry either by reabsorbing or secreting so it almost is like saying in the collecting duct you're giving the blood a last chance to get rid of things or to reabsorb if needed okay so there's a little bit of variable it says variable reabsorption or secretion of stuff so again look at the collecting duct as being the final steps you get a little last minute refinement going on and then the urine will go into the minor calx into the yes major calic into the renal pelvis into the URS into the bladder out of the body through the urethra see every time you get a chance practice practice the order of the urine flow out of the body okay or through the kidney and out of the body okay that is the functioning of the nefron okay now I'm going to stop the tape right here because I think that's more than enough for you to absorb no pun intended and then we will continue on this discussion in the next part of the urinary system which I'll tape for you for Wednesday okay okay so good night for now good luck on Wednesday's test