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If we don't look at the structure of the trying to the Ampyra low, it'll explain more detail. Is the most common size off implantation. Ah, fertilization in is more confident fertilization and therefore ectopic pregnancies. Also most likely implants in and pure as well on their four exactly pregnancy, most likely heard there, which is where problem might be. So in terms of the structure that you trying to you, um, we'll start from the outside and work our way in. So we have the ovary over here and you have the fimbria on the bit that just over here is called the INFUNDIBULUM. And it's the outer more spot off the, um you trying to you as you move a little more approximately. Get the ambulance. The ambulance is the widest on the thinnest wall and the widest bit of the you trying to you and it is the most common side of fertilization. It also does have got very tortuous world. A lot of, um, with lots of with a very complicated tortures. Mucosa on do. If you don't move further down, the wall gets thicker and the Lumen gets thinner. And so you get to the Ms which is this area over here. So the wall here, like I said, it is a lot thicker. And it's, um and they just gets thicker and thicker as you move into the mitre. So you will be moved to the intramural bits that that it has the smallest Newman as well. So technically, the pattern you see here that is getting from really wide toe a lot thinner on the wall to be coming from thin to sake that make sense. And I could mentioned earlier in the earlier slide on the cilia, the cells, everything that you find in the obese are still e ated and secretary. In order to move the over Malone and to keep the open Bible, we then we want to the male you productive tracks and label the most common land marks and features. We have the Penis and the Penis, the tissue, the competition. The Penis is made of two types. You have the corpus cavernosum wishes, the erectile tissue within it, um, which is the bit over here on the sides. And you have your copper spongiosum, which is where you reach around. So this myth bit in the middle you, then have your testies. And you happy? Did I miss the testies? Sit in the in the scrotum. Outside. Um, over here. This is the scrotum. These the testies, the sexy of the sites of the production off testosterone as well. A sperm and epi. Did I miss is the structure that sits right on top of the testies and responsible for storage off the sperm before the ready for ejaculation and during ejaculation, um, the sperm are transported from the testies by the vast difference, which is the stoop over here. And then once they passed by the prostate gland and the seminal vesicle nutrients is prostaglandins and foot shows that added to the sperm to create semen. The semen then drugs down the urethra on his ejaculated. So the quick pneumonic to help remember the pathways from giving accusations. Remember, seven up to start for the 71st tubules in the testies. So s and then go to the every time it's words store temporarily and then to the vast difference. And then by the jack, let you trucks that prostate gland and seminal vesicles, um, and then finally through the urethra and out through the Penis uh, like a magic earlier. This bit in this diagram is either could hear this pink bit is the corpus cavernosum, which is the erection issue to do an erection. You have a lot of blood flow in this area. Um, and then the bit below here is a copy spongiosum where you the urethra runs well, but then we want to talk about hormones, which is what kind of keeps the reproductive system running. Um, let's talk about why it all comes from. So when I think of reproductive home once first it comes to my head is testosterone on? Do the precursor of a testosterone is actually produced in the adrenal gland. Now the adrenal glands are pad better protein meal organs. They basically sit above the kidneys. This is the kidneys. Here on this structure is the adrenal glands. And it is a very important site of home one synthesis in the body. If we kind of cut through a doodle down and look what it looks like on the inside, we have the outer course X, which is this bit on the outside, and you have the inner Madeira. Now, each of these parts of the gland produce. Different types of hormones are different. Chemicals the ones were concerned with today are produced in the adrenal cortex, so it's a bit on the outside. If we look at that more detail and make a slice to look at the adrenal cortex, which is this part, we can see the different layers. So the most outside layer, the most external ear, is the donut glomerulosa. It would be sitting here externally, followed by Those are secure lot A and then forward by the zone A reticular is and the pneumonic I was taught to remember on which, which there's produce which hormones is like this. He's on a glomerulosa produces aldosterone, which is at home. One. We're involved with water and salt regulation in your kidneys. Um, and then is there a particular time I was involved with producing cortisol on doing a Ridiculous is involved with producing sex hormone, such as on DHEA and Anderson understand diet. And we remember this is that, um, we always told that delivers get sweeter as you go down, so you start with sold to go to sugar and then to sex, and that's how I remember it. So we're most concerned today with these on a regular is because that's where the site of sexual once it does, it happens. I'm gonna very briefly go with a sex hormones. And this is pathway, um, not into much detail. Just a stick of understanding. So the precursor for all of these homes sex hormones are cholesterol, and all the home was produced in the adrenal cortex is cholesterol. So buy a bunch of pathways on horm. Uh, Richard pathways and enzymes. You have a couple of intermediate chemicals and finally you get DHEA. The DHEA is an androgen as well. So androgens are, um, male hormones. Um, and DHEA is the first one that's produced in the pathway From here. DHEA can either go on to produce. I understand. I own which is another chemical in the pathway to the production Testosterone. All DHEA can go on to all to produce aldosterone of cortisol like we talked about earlier in the previous pathways to do. She is kind of the intermediate molecule. If it does go on to produce, understand, I own in sex hormone synthesis. It's quite important molecule because this is the main source of androgens in females in males. However, I understand die on is further since sized testosterone in the testies and testosterone is the main source of antigens in males. Then in females in the ovaries, testosterone is converted to estrogen by an enzyme called aromatase. Well, how is this regulated so well? You have a home one called ACTH, which is the adrenocortical job in common. On Do It is released by the hypothalamus and what it does that it acts. So it's released for the Advair pretty retiree, and what it does is it acts of regulates the production off hormones in the adrenal cortex on. So it first of all stimulates secretion. And if there's too much situation happening, it was negative feedback effects on controls, amount of secretion off home with between cortex. So we talked about how testosterone is produced in the body. But what exactly does it do? The straw Strode is primarily responsible for the development of sexual secondary sexual characteristics in males and females. So in males, for example, that encourages growth of pubic hair on, makes your voice deeper by my maturation of your vocal cords, and also you notice a a increase in testicular Peter sides during puberty, which is when this happens, as well as an increased muscle mass in females. You know there's something similar to have the growth of you pick her on. But, um, also you also noticed on increasing sex. Sex drive was well as increased muscle mass and bone mass well, so it's quite important in adolescence puberty. So the regulation of testosterone secretion happens like this. So the hypothalamus in your brain secretes gonadotropin releasing hormone, which is basically a regulator a hormone, and this is released in a pulse. It'll fashion. That is really important because if you would be released, gonna trouble it all at once and north in a political faction, this could desensitize your target organs to get out of trouble. Releasing hormone, which is what you don't want and that we have talents secreted in a pulse is highway. The gonadotropin releasing homework then goes and acts on your anterior pituitary to stimulate anti opportunity to secrete ever stage and LH FSH LH and then go on to stimulate testosterone secretion from the testies. On this essentially is the pathway for the secretions testosterone. But how would this regulated? Well, you've got a negative feedback loop at play here, so you have to watch the salt secreted is going to have a negative feedback effect on your intelligence until pituitary as well as your hypothalamus to decrease appellation and it's secretion and also decrease generates secretion. Let's move on to the menstrual cycle. So here's a short SBA someone be able to launch it, please. Okay. You I'm already seeing overwhelming majority, which is very encouraging. Okay, my under there now. Yeah, amazing. What really well done So young. Is that expired? Large res. Let's talk about what's my A. Larger you go on by the relevant of this question. So if you look at the uterus, we're going to talk about the different stages of the uterus and where the spiral arteries come to play and why they're important. So let's start by looking at the very beginning off the menstrual cycle when I'm very early on, your endometrium is just starting to regrow after the previous shedding, I said, call the early proliferative phase and basically what happens is that your connective tissue is rebuilding again and your glands are be reconstructed on your arteries and are being reconstructed a swell The reason this is happening is because it's anticipating the eventual implantation of embryo and therefore throat a menstrual cycle. Your endometrium is becoming more and more mature in order to be hospitable to incoming embryo potentially so in turn, in response to hormones such as estrogen and progesterone, you have here the growth off much more thicker glands on do a swell as, um, connective tissue, becoming more and more complicated in general. So he see here you could see all these glands that are straight in nature. They're not quite the little bit. I called the bit like Rex angles, now in the beginning to accumulate a bit of glycogen. But if you go onto the late proliferative of the creature the phase, you can see that these holes have now become a lot more complex than no longer hollow because of accumulated a lot more glycogen on Do this means they're almost ready. This is a security phase that almost ready to receive on implant embryo, and once it's fully developed, you also have spiral arteries. The spiral in arteries are basically the blood supply on to the endometrium. In the beginning on they are spiraling nature because they are really fine on provide a very fine blood supply as well. So during menstruation, what happens is that there's no fertilization that's happened. Then there's no need for the endometrium to be hospital anymore. And therefore the endometrium breaks down. And what you get is, um, getting the crosis of cells, you get these coiled spiral arteries breaking down as well on Finally, your net product is a bit of bleeding from the vagina. His know the SBA. I give it another few seconds. Yes, used to be a good of a split in this one, but majority you got it right. It is, in fact, a granulosa cells. Let's talk about what brain those cells are, um, on why they care about them. So in order to celebrate, it was felt that we have to understand what a mature follicle looks like, which is more granulosa felt have found so much. Your follicle, essentially is the structure containing the secondary you sites that's ready to break open and then allow a secondary decide to populate into the overdose, and therefore, let's look at what a mature follicle looks like. So if we started the outside, it is very thick layer of many cells. Your is called the Granulosus Alendronate, which is over here and initially this produce estrogen. But once once menstruation has started and once per traditions not taking place on the Corpus luteum forms going, you know the cells such pretty progesterone instead, Um, and then you also have here a secondary use. I wish is the star of the show, Really? And it's surrounded by primary layer of zona polluted out, which is a little black proteins and then back on a radio, which the crown of cells and these are important when it comes to foot the active fertilization by sperm itself. So this is just before ovulation on after the first myotic might Arctic Division on Go this this follicle is ready to obviously basically first talk about the menstrual cycle. I know this can be really complicated to understand it first, cause there's so many things happening at the same time, I'm going to try to simplify it on, so we have few different columns at play here. The first one here is what's happening in the ovary, which is on top. The second is what's happening with the hormones simultaneously and finally, what's happening with the uterus At the same time, all of these structures respond to hormonal changes, and so we're going to go through each one and see what happens along. Don't mention like so a normal menstrual cycle last 24 38 days with the first day of menstrual bleeding counted as day one off cycles that would be over here mantes last average of 3 to 7 days, with an average blood loss of 35 to 50 mills of blood. I need the mentioned cycle like a gorilla involves simultaneous changes in the ovaries on the usual. So it's important to understand that the mental cycles a very tightly regulated process in which the coordinated relief off hormones from the hypothalamus and the pituitary gland on the go nuts produces a single mature use I. Because the gold of each line third cycle is to mature new site on release it such that it has the chance to be fertilized and develop into an embryo that's viable. So we start at the beginning. After menstruation, we have the follicular face over here on. We could see essentially what happens is that none of the follicles of particularly mature. The hormones are a baseline level on the uterus is just starting to rebuild itself again. So what's happening here? Well, basically, what happens? What stimulated whole process again is generates, which is good, not a drop in releasing hormone and got a job in releasing hormone stimulates the anterior pituitary to release ever such an LH. Now, every second, let's we'll go on to act on your ovaries over here. So primarily FSH is important in stimulating, um, the mature a shin off follicles in the ovary such that at the end there's one dominant follicle that's ready to ovulate on. It also stimulates granulosa cells like we saw earlier. They're on the outside of the follicle to secrete estrogen. A late on the other hand, same. It's speaker cells in the follicle to produce progesterone. Estrogen and progesterone have a profound effect on the maturation off articles on the release of hormones, the release of estrogen and progesterone, which is really important and basically drive your menstrual cycle. But it's really good feedback loop here. So when there's too much when, whenever statures release a sub sub like a normal amount or the required amount of estrogen. You want to make sure that only one main follicle is dominant. Only one follicle is going to be ovulated and therefore you want to inhibit for the secretion of FSH. And the way you do this is that there's a feedback loop exist. So once the amount of estrogen secreted has a cross a certain threshold, this then negatively feedbacks and inhibits for the release of ever such and therefore inhibiting the further maturation of any other follicles in the ovary. So what's happening now is you've got this release of Easter gyn and progesterone on. As you can see here, it's increasing on. Consequently, you can see that the uterus lining is also thickening at the bottom, you becoming thicker and thicker and more complicated. And then you have ovulation. So at the time of ovulation you'll see an alleged surge. So what you see here is a sudden increase in L. It's a very steep increase on this is the steep increase that stimulates ovulation. So what happens here is you could see here this is the tertiary graph in follicle, and it's going to break through the Lyrica albuginea off the ovary to enter. Um, the reduct. Great. Sorry. Okay. And then what happens after that, essentially, is that your mature who site sits in The only doctor waiting to refer to that is on a fertilization doesn't happen in our case. Over here, what's gonna happen is that this new tricks that's been building for the last month is going to break down on the loose side is also going to undergo a pop closest and also leave along with the degenerated you turn cells and it's going to cause menstruation. But if this does not happen on if there is still scope for fertilization, then the granulosa cells remaining of the ovary with mature into what's called a corpus luteum. The Corpus luteum is basically this mature structure that begins to produce progesterone that will maintain the uterine lining in the case that there is fertilization and there is a potential implantation. And if this is on, occurred in the corpus luteum becomes the Corpus Albuquerque's, which is basically a, um, a white fibrous scar that remains in the ovary. So where can it mentions? I could go wrong. Well, it can happen because the developmental problems, uh, if you have feel if you're late to go into puberty, for example, Um, and does she not developing a secondary sexual characteristics on time? That's a bit of an alarm bell. Um, and this is called Primary Amenorrhea is when you have delayed onset off off your menses and there are many causes for these, for example, it could be because your home one laxatives are taking a bit longer to activate or could even read you to genetic abnormalities that mean that need a have a nimble unsorted set for months in your body. You could even be due to People who pay may be really competitive sports or have eating disorders because this can cause in balance off chemicals. And it could cause hormonal, the circulation your body. Or if there's a CNS tumor, which means that on inappropriate amount off, generous is being released and there's not enough. And if there's not enough generators being released, that means it's not going to stimulate your reproductive system enough to produce enough insulin and progesterone. And sometimes you can also have a problem where you are getting enough generators, but the problem is in your ovaries, and they're failing to to produce estrogen and progesterone. And this can happen in genetic disorders like Turner Syndrome, where you only have a single X chromosome as opposed to an X and Y chromosome. So primary amenorrhea here, in summary, can either be generated dependent where you're not having enough generates, or you, Jared Independent, where the generates is not the problem, but driving problem somewhere else, like in the ovaries. You can also have a secondary and menorrhea, which is where you get irregularities. Your menstrual cycle do to secondary problems pre existing diseases or due to the introduction of medication or your lifestyle. For example, obese women are more likely to present with amenorrhea pregnant women, women who are contraceptives or antipsychotics. Um, although these other environmental factors that can also affect on the regularity of the cycles Well, cookie cover contraception briefly as well everywhere of the time of the moment. And we just do this s p A. This might be a bit tricky. Um, okay, okay. Okay. It's over the Yeah, really Well done. That's correct. And the majority of you got it right. It is, in fact, the answer D So this question is asked me to consider the combined order contraceptive pill, and it's contraindications in women. And let's talk about different types of contraception on why this is the right answer. So the combined or contraceptive pill is actually a pill that combines estrogen and progesterone to get the doors of insurgent and progesterone When you take the pill, and the way it works is that inhibits population basically and their void extra hopefully prevent pregnancy if taking correctly. And there are certain on country indications for this pill. Um, according to the nice guidelines, at least option is wrong, because the combined contraceptive pill is contraindicated when the women's be a miso over 35 not 28. Um, option B is also long because, um, by saying she's to use both partum, I'm implying that she's less likely to be actively breastfeeding at the moment. On breastfeeding is an active contraindications to see OCP, and therefore it's not this answer. Um, smoking is a contraindications to the c o. C. P, but only if the woman is aged over 35. Um, on the last one, um, the combine or contraceptive pill actually result in a reduced risk of ovarian cancer, and so her mom. Having ovarian cancer is not a risk factor. Anything the CCP actually protects against it on CRCP action provides a course significant risk for venous thromboembolism. And therefore, if she has a history of Ambulate probably embolisms in her family, then that means that she may be predisposed to it on that can make her taking this. You see if he quite dangerous. So let's look at all the kinds of contraception. The most common kind wouldn't talk about Value message first, because they are the only message of contraception it helps protect against STD eyes. They are not 100% present present, effective, however, condoms if taken and using with park. If use perfectly, they can provide up to the 98% on VESIcare. See, however, with typical use, is only about 82%. Um, diaphragms and cervical caps are basically silicon cups that fit over the cervix and prevent semen from entering the uterus. Um, so the woman basically fits, then, before having sex and then leaves them into place, leave them in place for about six hours, forced intercourse on. Ideally, these die from that cervical caps have to be used in conjunction with Spermicide Joe to further reduce the risk of pregnancy. So he used the cervical cap perfectly with spermicide. Then your risk of preventing pregnancy transfer Enbrel is it can be up to 95% so they are quite effective. However, they do awful very little protection against STDs. The combined or contraceptive like we match it earlier is one of the most common kinds contraception. She's the women today, um, it requires you to take it every single day at the same time and therefore you you need to be quite regular with it. Otherwise, with a typical use, you get a lot less on efficacy with it. It provides a lot of benefits. Apart from contraception, it also helps in on people who present with painful periods or amenorrhea also can also have had a side benefit of reduced in the risk off, endometrial or very and colon cancer. However, any chemical you put into your body doesn't come without side effects, and the same applies to see UCP. So like we discussed earlier, you have a risk off a venous thromboembolism, which could be quite dangerous with the cells. But also it can cause like breast tenderness and pain on also certainly increases your risk for breast. And so the cancer. You also have the progesterone only pill, which is just the dose of progesterone on its own. And this works by making your cervical environment inhospitable to sperm. So it thickens the mucus, making it hard of a sperm to move along up the reproductive tract. And it also makes your endometrium less hospitable for implantation. Emergency contraception. When it comes to that, the three main types sheets? No, the first type is never a gesture, which is just a high, a large dose of progesterone. Your view. The Pristiq, which is a progesterone receptor modulator. And you have a copy coil. Um, speaking practically. Most people tend to choose level gestural and your crystal for comedians purposes. But really, the copper call is the most effective. Um, because it firstly acts like a spermicide on also has very little side effects as opposed to a level a gesture. You're really press two. Ah won't go into the details for the sake of time. But read this new one time that he can. I'm probably going to talk about abortion. I realize is a bit of a sensitive topic, but I quickly going to go over. But the general guidelines in the UK so in the UK, abortions are legal until about 24 weeks. Um however, medical abortions, given the procedures we use today, are most effective in the 1st 62 days of conception. Just the guidelines given on the drugs used as of now to acidity it, abortions are moving Prestone and jump roster. I'm not gonna go to detail how these work, but quickly the way these work essentially, is that what you want to be able to do is you want to be able to basically remove all the tissue from the uterus that has grown. Daughter bought the fetus, and it also do this. You want to make sure that they use is able to detach itself from the tissue and the tracks on get removed easily, and you also want to minimize bleeding. So I remember Preston, Does that mean for Bristol on sensitize is the uterus prostaglandins, which makes it more susceptible to contract Shin on. It makes the endometrium in a hospital, which makes it more difficult for the implanted embryo to survive. And then Jim crossed helps in exporting or extra the expulsion off the tissue doing before the surgical procedure. And finally, very briefly going to touch on ST. I see, um, the most common STD eyes in the UK are chlamydia. Um, HPV on, um, gonorrhea in that order on 7016. But the most common population that tend to be more vulnerable to ST I see, uh, those in young age, probably because of more recreation activities, um, men's have men who have sex with men as well as Africa be in populations. Uh, this is what I'm going to go into. The asset's a time, but I'm sure we're gonna cover this more digital in later lectures. Uh, that's a lot for today. Thank you so much Listening. You have any questions at all? Uh, please put them in a check. I'll be happy to answer them. Go ahead over to make it. Thank you, Jonathan. That was a really good comprehensive. Talked with such great explanations. And thank you so much. I'm just a night. Everyone I know we are running over slightly. The feedback form has been released. So if you could give me back toward two speakers would be really, really grateful. Um, but I will pass over to path just to finish yourself with a bit of, um, Reno in kidneys. In case the highlight was so good I was gonna start screen sharing. Can you see this? Yeah. Oh, good hands. Gonna powerful screen. Okay. Um okay, so so Hi. We're gonna be talking about the renal system today. Now, um, this is going to probably be a bit rusted because they're a bit short time, but so but the topics will cover today our anatomy of the kidney forces of filtration at the GLOMERULUS. The nephron structure on P hates regulation. So what do the kidneys do? So, to begin with, um, it can be summed up into three basic functions, So filtration ribs option and secretion. So, for example, blood filters is so blood is filtered to remove excess water, minerals andi urea to produce urine. So the kidneys haven't important role in many homeostatic functions, such as acid based violence, electrolyte balance, water balance. And it also plays a role in regulating our BP. Um, two. So it's also known to also produce vitamin D and also red blood cells on release and write the poet in into the blood in response to low blood oxygen levels such as like situations like hypoxemia. On Finally, the kidneys are also known to do gluconeogenesis. Um, there are really two organs in the whole entire body that can actually do a lipid genesis and that the other being the liver. So now we'll begin to look at the kidney anatomy so the kidneys are found in the right and left hypochondrium. Um, they're retroperitoneal, meaning that the kidneys have found behind the party. Um, and they're attached to the peritoneum. On one side, they're found in the level off the 12th thoracic. An upper three lumbar vertebrae on the right kidney is slightly lower than the left is. You can see in the diagram here, and that's because of the presence of deliver right above it. The highlight of the kidney lie at L1 and therefore said to lie on the transplant. Lorik Plain, the Transpyloric Lane, the Prince. The Transpyloric plane is an imaginary axial play in located midway between the jugular notch on the superior border of pubic symphysis. And basically it's really important anatomically because it's a landmark that tells you where the abdominal stretch has passed through this place. So it's the level whether or origin off the superior mesenteric artery is on that supplies the mid go. So the kidney has a fibrous capsule which is surrounded by a layer off fat on. Basically, the fat acts as like a shock absorber. Leah on Finally, that is you can see above the kidneys here does the adrenal gland adrenal glands on that found superior to the kidney and the separated from them by a layer of renal fascia. So, as mentioned earlier, a good way to remember what the retroperitoneal organs are is a quick we're not know monit called sad pucker, but I was going to skip over it for now. But you can look over it, Um, once the slides a route. So now we're gonna die deeper into the kidney anatomy. So there are two main layers off renal parent comma the cortex, which is found in the periphery from here on down the medulla, which is found a bit deeper inside the layer. So whilst the renal cortex lies in the periphery, there are things called renal columns with some middle medulla really extensions of the renal cortex, which separate 10 to 14 renal permits from the renal, medulla and urine on your nissen produced in these renal lobes and each renal Oh, ball drain into the papilla into a minor Callixte So But for in 45 renal, uh, four or five minute callouses together from the major Calix on these major callous ease will join to form the renal pelvis. So on the real pelvis, extra extends past the ureter the extends as the ureter all the way down to release urine. So now we're just going to quickly move on to the blood vessels. So the blood vessels and the lymphatics of the kidney are quite straightforward and simple. So the arterial supply is at the level of L1 to two. On the other, Onda renal arteries was in a strange occurs via the renal veins. So lymphatic drainage of the kidneys goes from the power aortic lymph nodes and at each hilum from anterior to cost area, you'll find the tributaries of the renal vein on branches of the renal artery and the renal pelvis, which continues as the Rita in that order. So if you look at it from anterior to posterior. It's a vein artery, pelvis, and you can remember that live at. So I in this light, I've just quickly highlighted the passage of blood all the way from the renal artery all the way down to the renal vein. I went quickly. Skip over it for now, but you can always revisit it afterwards. So now we're going to move onto nephron structure. So there are three main things that can happen at the nephron. Um hum a relief, it filtration to bill of re absorption on secretion. So now let's take a look at this image. So, as you can see here in Section A, um, we can see that her water and solid, smaller than proteins are forced through the culprit. We walls on the government, the glamour, the grammar. The glomerular capsule pours into the renal tubule on then. Now let's take a look at section B here. So here, water glucose and mean acids on essential I owns have transported out of the filtrate into the tubule cells and then entered this capillary blood. And now let's have a look at section see which could be seen here. Um and here protons, potassium ions, creatinine on drugs are removed from the peritubular blood and that's secreted by the tube. Your cells into the filtrate case and nephrons are the functional unit of the kidney on that structure could be observed in these diagrams. So So the blood initially is filtered at the glomerulus on the filtrate. Going through the Romans capsule goes into the proximal convoluted to bill and then through the proximal straight table, making its way into the making its way into the thin, descending loop of Henle A and then into the thicker ascending. To go ahead and and passing through the, um, distal complete to book, um, and then travels through the cortical collecting ducks before exiting via the renal pelvis, and then consequently exits fired the ureter. So note that so note that the two bowls of surrounded by peritubular network of capillaries and this allows the control movement off molecules between the filtrate on the blood. So now we're gonna look at the two types of nephrons because you can see here there are jokes to medullary nephrons which the ones that tend to that we tend to learn about, usually in lectures but they passed all the way down into the inner medulla on a quite long compared to the cortical nephrons, which is shorter on Don't pass all the way into the deep from Adela. So about 85%. So about 85% of our nephrons in the human kidney are cortical west. Only 15% are jokes to medullary. But because all nephrons join collecting ducts that run through the in the medulla, all nephrons still have a hyperosmolality of the enema Della to concentrate the urine into. It's a if given the appropriate conditions. So, as I previously mentioned, ah, you can find the gorilla a cup capillaries in the Bowman's capsule on day. A drain into the proximal convoluted to bill on the PCT is followed by the peritubular capillaries to during the cause of and during the cost of the P. C. T. Most of the islands and other nutrients in the field trade such a glucose. And, um, you know, acids are reabsorbed, so the vase, a rector, is the blood vessel that that follows the roof of handling all the way around on D. This means that the first part of the kidney to suffer if BP is low is the medulla. Um, this is because Oh, sorry. It's any. This is because only 1% of the blood that enters the kidney will enter the vase. Rector, which supplies the in a medulla on, therefore, the in, um, Adela is a sensitive to poor blood supply, meaning that it's more likely be damaged if we have a low BP. So here I've just summarized the rules of each parts of the nephron. But feel free coverage of these in your in time. Okay, So moving on to to be transformed mechanisms. These tend to be quite similar to the ones covered in the previous topics of the cost. But we'll concentrate on the reabsorption aspects as well as covering. What hormones tend to be tend to be either what hormones tend to do so. Reabsorption tends to be either paracellular or trans a little, uh, in nature. So Paris a little pathways tend to be passive on simple diffusion. However trans a little pathways tend to be. You tend to use facilitated diffusion by some sort of transport. So an example of this would be a sodium Protonix change. Er And that's found in the proximal convoluted tubal, as well as the SGLT one on the SGLT two co transporters, which transport glucose and sodium together from the tubule um, it into the tubule cells. These these movements of passive, however, other transports in the middle. Other transport is in the membrane of the tubule cells require ATP and, uh, therefore active processes. Um, one common example founded many two bills, um, cells is the sodium potassium ATPase on the base Electromed on another example would be proton ATPase in the PC to use for per 10 secretion. Um, so there are four main hormones that we can have that affect rips reabsorption. So aldosterone is one of them, and they act in the site of the distal, convoluted tubal and the collecting ducts, and it contributes to the reabsorption of sodium and water. Also know that it plays an important role in the secretion off potassium. So now we have under tension angiotensin two, and this acts on the proximal convoluted tubal on the loop of Henle E and collecting ducts has a similar role to aldosterone, where it helps to reabsorb sodium and water. So now listen ADH age age acts on the distal, convoluted tubal and collecting ducks when it's president, causes the reabsorption of water by coordinating aka parking's to come up to the apical membrane off the tube, your cells. And finally we have court so and this acts on the proximal convoluted, terrible, and it has a role in the absorption, off sodium way we focused on the ribs option rules of these hormones. But these hormones also have a role in P. Hates that will touch on a bit later. So quick, SBA Which of these is not a common point of narrowing along the Rita? Um, okay, I think I'm going to closed that just for time. So is that your terror tubulus? That's not a narrowing, but A B and D all are you totally does not exist. I just put that as an option. So now we're going to move on to the forces of filtration at the glomerulus. So the glomerulus is the site of filtration in the nephron, and it consists of a vascular pole. Um, as you can see Onda, it consist of a vascular pole, which is where the Afrin and Efferent arterial arrive and exit from the Glomerulus. So there's a urinary pole here, too, which is the start of the renal tubule and off these two poles found opposite each other at the moment capsule. Um, there are two poles, and they form a knot of capillaries where filtration of the blood into the filtrate occurs and which, and they gather at the Bowman space of the Bowman's capsule. So the filtrate collected in the diluted So is the diluted solutions of water salts, nutrients and waste on day all exit by the proximal convoluted to milk tubule. So there are three layers involved in Ghana glomerular filtration. So going from the capillaries to the bone going space, um, to the Bowman Space, Um, there is a fenestrated capillary membrane, followed by the GI BM, which stands for the Globe glomerular basement membrane. And finally, that's followed by the inner layer Bowman's capsule, which is formed by the potty sites which, with their foot processes between the foot processes. There are filtration slits with the diet with the diaphragms, which is known to be the most restrict of pot of the frustration barrier. So these off these three less of these three layers will present prevent the passage of molecules larger than for nanometers on. This includes proteins and also cells such as red blood cells. Um albumin, which is also one of the most common proteins found in the blood, is actually 3.592 m and damage it, but it does not pass through the filtration barrier on. That's because albumin is negatively charged on on their four. It's repelled inorganic salute. Such a sodium potassium they can pass really through the filter on bacon. Also a chlordiazepoxide they're so small can also past, even though the negativity charged, too. So I'm going to quickly go over glomerular filtration rate. So as you can see in the equation, um, hum infiltration rate is on is usually measured in milliliters per minute, and you can see in the creation use that that a K F is the pill tray shin coefficient that is determined by the glomerular capillaries permeability on the capillary membrane area available for filtration. The net filtration pressure is calculated by working out the difference between hydrostatic pressure, where PC is the hydrostatic pressure and the capillaries and P B is the heart static pressure in the bones capsule on subtracting it from the colon. Does Martic procedure on the Grady in from this? So, as you can see in this diagram in the bottom here, a change in tone of Afrin and effort arterial and solid protein concentration of blood can be can affect net filtration. Pressure has shown in the diagram below. Here on there's a dilation of the Afrin. And then, um then more blood has access to the glomerular capillaries, which means of rise in hydrostatic pressure except in the capillaries. A similar similar scenario occurs with the Afrin at you is constricted, and that creates an increase in heart static pressure upstream from the site of constriction at the granola capillaries. So now we're going to move on to our two regulation of gear. Far so, auto regulation of jafar is important as arterial BP can change quite drastically, depending on what activities of being performed. So over a wide range of arterial blood pressure's the G F R. Is able to stay fairly consistent, as it has shown in the graph here, Um, so without any regulation to the G f r, an increase in the arterial BP would lead to uninterested in the renal plasma flow, which would lead to an increase in the hydrostatic pressure within the glomerular capillaries. Given the equation from the last slide, this could have an effect on increasing that filtration pressure and lead to an overall increase in G fro. But of course this doesn't happen, and they're to entrance. This isn't always happen in their two intrinsic regulation mechanism that the kidney uses to control G F R. So first, let's look at the myogenic mechanism and on the two below glomerular feedback mechanism. So the myogenic mechanism is where the Afrin arterial constricts due to the action of my sides when stretched and relaxed when released from stretched that this helps to maintain a strategy far when confronted with changes in the arterial BP on As you can see here, um, you have the two blood Releford back coordinated by the Michael Dancer, which is which, as you can see here is, is thick ascending limb off the loop of Henle E, and the the distal convoluted to bruise on the role of the macula denser is that it senses the sodium chloride load, or uptake. If there's an increase in somebody in Korea detected. This implies that flow rates too high for appropriate sodium's option. So in response, the macular denser release ATP, which binds to the Afrin arterials and causes it to constrict, which lowers both the groom L0 capillary pressure and the renal plasma float. Um, it's also important to mention there's an extra music mechanism to a the come control of GFI. So one thing it to remember is that there's the rent and angiotensin system on the renal sympathetic nerves system. So this just quickly summarize is the tablet feedback mechanism that we just spoke about. So I'm going to skip over the renal function test. So now, um, so we'll now be moving onto the kidneys role in p haste regulation. So there are two main systems involved in be hate, um, regulation. So, um, in acid based home associates, we have the lungs on the kidneys. So the respiratory system is responsible for excreting oh to whilst the kidneys deal with a non volatile acids. Non volatile acids assess produced from the body from sources other than carbon dioxide, and it's not excreted by the lungs. So the normal western meat containing diet would lead to a net addition off acid to the body, there are four main buffers in the blood that can be used for so to a non volatile acids in organic force bakes plaster proteins, hemoglobin on bicarbonate. Out of these, the ones that provide the one that provides the best birth incapacity, the bicarbonate due to being dynamically controlled by both the respiratory and renal system. So, um, this is a general creation of when non volatile acid is neutralized by bar carbon it. So this shows the non volatile acids are buffered by a buffet by the bicarbonate and excreted so to this is not sustainable unless the kidneys produce bicarbonate to replace the Baikonur that's lost in the process. Therefore, the kidneys are responsible for regulating the bicarbonate levels too much the acid base homeostasis in the body. They are the nets produces of my cominat. Um, there are four requirements of net production of bicarbonate so reabsorption of filtered by cabinet production off by carbon and protons, and the proximal convoluted to bill allowing the secretion of protons and the return of bicarbonate to the plasma buffering off to bill it protons to allow for the secretion to So here in the middle diagram, you can see the 80% of bicarbonate is reabsorbed on happens in the p C. T. Now, what is this process that allows us to happen? Well, the process has shown in the diagram on the right here. Um so if you take a look at that diagram bicarbonate reabsorption requires proton cycling, which has shown in the diagram, as you could see because the protons being secreted into the filtrate but reabsorbed into cells that line the tubules. Oh, as you know, to on water. So due to the action off carbonic anhydrase go to and water from bicarbonate, which is reabsorbed in the blood Um, I'm going to quickly skip over this, but do you have a look over it? What if you have time eso Now let's look at the intrinsic control off the pH. So you have, um so intrinsic controls the first you have the increase in proton secretion on dad. They'll be increasing bicarbonate. Reabsorption do two more proton cycling occurring. Secondly, you have the protons secretion is that that's influenced five p hates, for example, low pH means that protons and the tubal cells, which means more want to be secreted to dissipate the protons, um, Proton Electric and I'm cold Grady in next to have an increase in the P CO2 levels on that causes increase in so two in the tubeless else, leading to a decrease in page on. This means more pertinent secretion and bicarbonate reabsorption. And finally, the expression of activity of several of the transporters increases at a low peak. Hate, and this is possible due to autocrat and paracrine effects of endothelin. And finally, I'd like to go over the extrinsic control of the page. So card still is released in response to a low pH on, um, performs. It's action at the P C. T, where increases transcription on certain transporters. So we've already covered that card is still increases soda and results reabsorption. However, it also causes an increase in proton secretion and cycling, meaning that more, um only in trapping occurs and overall, more bicarbonate is reabsorbed, so parathyroid thyroid hormone is released in response to prolonged acidosis on it has two main roles in the nephron increases. Proton secretion in the thick, ascending limb of the loop of Henle, a on the distal convoluted to bill. It also has a decreasing effect on the inorganic phosphate reabsorption Um, and therefore there is more buffering potential in the tube lift limit to accommodate for uninterested in the proton secretion you have angiotensin two on that will stimulate sodium and potassium exchange in the proximal computer. Convoluted tubal, as the name suggests, it causes an increase in sodium reabsorption and proton secretion similar to the action, of course, a lot on increase in ammonium trapping on bicarbonate absorption occurs as a result, and finally aldosterone so. The stent This stimulates the potassium proton ATPase in type a enter kelated cells found in cortical collecting tubules on. As the name suggests, it causes an increase in proton secretion and an increase in potassium reabsorption on the effect of proton secretion. Again, it's similar to the ones that would already mentioned and and this is the final slide, and it's basically is covering how to approach and acid. What type of us a pseudocyst are close is's. So this three attempts to figure out what it is this first look at the pH is that acid article. I I next look at the cause of behaves. So consider is consider. Are the levels of coatue and bicarbonates high or low, And then you just asset assess whether there's compensation occurring. So this is just a really quick diagram that shows it. So, for example, if we were presented with a really low pH below, the 7.35 is they're raised to go to on P CO2, Um, let's say yes. That means it's respect to our pseudocysts. Then we ask Is that is the bike operates? If it's not, it's uncompensated. And if it is, it's compensated. So just look over this diagram and it should help, um, when looking at these type of questions, but I think I'm gonna end it that, um, thank you for attending. Please fill out the feedback forms on Pass it back to my God, Thank you so much. Power. I'm sorry. That was ended up being so rushed, But thank you for going really Well. Um, I just want to thank you so much. Everyone that was stuck around. I hope it was really helpful for you. And we have three great presentations from to really great speakers. So thank you. Both girls they were amazing. I put the feedback form in the chat. If you could just, um, feel that in before you leave, and then you'll be able to get the slides and the recording a soon as we can get them up for you. Um, but thank you so much for attending everybody. We hope it was useful on make sure you come on Saturday when we got the final session of our back to school Siris, where we're covering urology embryology on some pharmacology as well. Also got finals easy session tomorrow as well. And gastro. Probably applying a lot of the physiology you guys talked about today to, uh a lot of the clinical medicine you need to know in gastroc should be useful if you're interested as well. Yeah, well, the guys you know, good stuff. Really good content. Guys. Ready? Good. Um, I think you'll find a list of future sessions on our social. So if you I think there was shared early, Uh, so just look at our schedule official on Instagram and Twitter and just ask easy on Facebook too. So that will be on there. So this week we just have finals. Easy gastro tomorrow. And on Saturday we got the back to school event. I think I'd say for this week, right? Yes, it Thanks. Street, um, the links are on are linked tree in the north. Um, the Facebook stop. Stop the recording.