Urinary System Part 3

Summary

In "Urinary System Part 3," Larry Young explores the intricate processes of urine production within the urinary system, focusing specifically on filtration within the renal corpuscle. Key processes include filtration, which involves fluid movement from the cardiovascular system to capsular space, and the interaction of structures like fenestrated capillaries, basement membranes, and filtration slits which each have unique functions to control what is filtered out. The video delves into the roles of blood hydrostatic pressure and colloid osmotic pressure in maintaining filtration, focusing also on the regulation mechanisms, particularly the role of the juxtaglomerular apparatus and the renin-angiotensin-aldosterone system in managing blood pressure and volume.

Highlights

• Larry Young breaks down the urine production process, emphasizing the dual steps of filtration and reabsorption/secretion. 🌀
• Fenestrated capillaries, basement membranes, and filtration slits each have unique exclusion criteria based on size and charge. ⚖️
• Higher blood hydrostatic pressure in the glomerulus is critical to ensuring filtration throughout its structure. 🚀
• Juxtaglomerular apparatus plays a key role in sensing and responding to blood pressure changes, modifying filtrate production. 📊
• Renin-angiotensin-aldosterone system is a key player in increasing blood pressure when needed, ensuring the body’s homeostasis. 🧠

Key Takeaways

• Filtration in the urinary system is crucial for urine production and involves complex layers and processes. 🚰
• There are three main barriers during filtration: fenestrated capillaries, basement membranes, and filtration slits. 🛡️
• Renal filtration requires the precise management of blood pressure which isn’t allowed to drop to maintain constant filtration. 📈
• Regulation of filtration involves sophisticated feedback systems, like the juxtaglomerular apparatus and the RAA system, to control blood pressure and volume. 🔄
• Blood pressure regulation by the kidneys is an ongoing, dynamic process involving multiple organs and systems. 🩺

Overview

In the intricate world of the urinary system, part three of Larry Young's series takes a deep dive into how our bodies produce urine. The star of this episode is filtration, an essential function that takes place within the renal corpuscle. The process, as detailed in Young's presentation, is anything but straightforward, involving several barriers that meticulously regulate what gets filtered from our blood.

The discussion kicks off with an in-depth look at the barriers involved in the filtration process. These include fenestrated capillaries, basement membranes, and filtration slits, each playing a vital role in determining what substances pass through. Young explains how these barriers leverage things like size and electrical charge to either include or exclude substances, making filtration a highly selective process.

Beyond the nuts and bolts of filtration, Young brings attention to how the body regulates blood pressure to ensure effective urine formation. This is where the juxtaglomerular apparatus and the renin-angiotensin-aldosterone system (RAA) come into play. These complex feedback mechanisms ensure that blood pressure remains within a range that supports continuous filtration, highlighting the profound interplay between our cardiovascular and urinary systems.

Chapters

• 00:00 - 00:30: Introduction to Urinary System Part 3 In this chapter, we delve into the actual process of urine formation within the urinary system. The discussion emphasizes that the process is mainly divided into two primary components. This section serves as an introductory segment to outline the subsequent processes involved in urine production.
• 00:30 - 01:00: Filtration Process Overview The chapter provides an overview of the filtration process, distinguishing it as the first stage in a two-step procedure involving filtration and reabsorption/secretion. Filtration occurs within the renal corpuscle, while reabsorption and secretion take place in the tubules. This segmentation into two distinct steps emphasizes the different locations and processes involved in efficient renal function.
• 01:00 - 01:30: Dividing Processes by Location The chapter titled 'Dividing Processes by Location' focuses on distinguishing various processes in the kidney by their location. It specifically mentions the proximal and distal sections, as well as the loop of Henle. The chapter promises an overview of the process of filtration in the current video and indicates that the last video in the series will cover the processes of reabsorption and secretion.
• 01:30 - 02:00: Understanding Filtration Terminology The chapter titled 'Understanding Filtration Terminology' focuses on familiarizing readers with key terms related to the process of filtration. It emphasizes the importance of understanding these terms to effectively engage with the subject matter.
• 02:00 - 02:30: Filtration Mechanism In this chapter titled 'Filtration Mechanism', the focus is on the movement of fluid from the cardiovascular system.
• 02:30 - 03:00: Details of Filtration Barriers The chapter titled 'Details of Filtration Barriers' involves a detailed discussion on the process of filtration in biological systems. It provides an understanding of the role of capsular space in the production of filtrate and distinguishes it from other biological processes.
• 03:00 - 04:00: Fenestrated Capillaries and Size Exclusion The chapter explains the processes of reabsorption and secretion in the body, specifically focusing on fenestrated capillaries and their role in size exclusion. It discusses how reabsorption involves the movement of fluids, indicating a crucial aspect of the body's internal filtration and fluid balance system.
• 04:00 - 04:30: Basement Membrane and Electrical Charge Exclusion The chapter discusses the process of secretion in the context of fluid movement, specifically focusing on how liquid components move through the tubules into the capillaries.
• 04:30 - 05:00: Function and Regulation of Filtration Slits This chapter discusses the function and regulation of filtration slits, focusing on how fluid movement is defined not just by the liquid or water component but by everything dissolved within this liquid. The process involves materials crossing the membranes, and the concept of secretion is revisited in this context.
• 05:00 - 06:00: Illustration of Filtration Layers The chapter 'Illustration of Filtration Layers' discusses the process by which fluid moves from capillaries into tubules, providing foundational understanding of the filtration mechanism. It highlights a diagram that offers a visual perspective of this biological process.
• 06:00 - 07:30: Filtration and Solvent Drag This chapter explores the processes of absorption, reabsorption, and secretion within different parts of the nephron in the kidney, focusing on the loop of Henle, distal convoluted tubule, and collecting duct. Emphasis is placed on reabsorption in the loop of Henle and the collecting duct, while secretion is more prominent in the distal convoluted tubule. The chapter underscores the dynamic balance between these processes in kidney function, crucial for filtration and solvent drag mechanisms.
• 07:30 - 08:00: Impact of Podocytes on Filtration The chapter titled 'Impact of Podocytes on Filtration' focuses on the role of podocytes in the filtration process within the kidneys. The initial part of the transcript highlights the processes of reabsorption and secretion. Reabsorption is emphasized in the proximal convoluted tubule and again in the collecting duct, while secretion is emphasized in the distal part. This sets the stage for a deeper examination of the filtration process and the specific impact that podocytes have on it.
• 08:00 - 08:30: Interpreting Filtration Pressure The chapter titled 'Interpreting Filtration Pressure' focuses on the movement of fluid and molecules from the capillaries of the glomerulus into the capsular space. It highlights the complexity and nuances involved in understanding this process, emphasizing that while the basic concept is straightforward, the details reveal the complexity inherent in accurately interpreting filtration pressure.
• 08:30 - 10:00: Regulating Filtration Pressure This chapter discusses the process of regulating filtration pressure in the kidneys. It explains the role of the glomerulus and capsular space in filtering blood and mentions the three layers that separate the glomerulus from the capsular space, including the fenestrated capillaries.
• 10:00 - 11:30: Blood Pressure and Filtration Regulation The chapter discusses the structure and function of kidney filtration components, such as the basement membrane and filtration slits. These elements play critical roles in the selective exclusion or allowance of substances, based on distinct criteria, within the filtration process.
• 11:30 - 12:30: Role of Juxtaglomerular Apparatus The chapter explains the function of fenestrated capillaries, which exclude larger entities such as red blood cells and proteins due to size constraints, thereby preventing them from passing through. It also mentions the role of basement membranes in selection.
• 12:30 - 13:00: Regulation Through Sympathetic Nervous System The chapter on 'Regulation Through Sympathetic Nervous System' begins with an explanation on selective exclusion or allowance of substances across membranes based on electrical charge. It emphasizes how the membrane itself carries a negative charge, which influences the movement of various particles. The narrative takes the example of albumin to illustrate these concepts.
• 13:00 - 15:00: Review of Renin-Angiotensin-Aldosterone System (RAAS) The chapter discusses the Renin-Angiotensin-Aldosterone System (RAAS) with a focus on the filtration properties of the kidney's basement membranes. It explains how negative ions or molecules, such as albumin, are repelled from passing through because the basement membranes are negatively charged. This electrostatic repulsion prevents albumin, a protein, from passing through, emphasizing its large size and charge, although small enough molecules might still pass.
• 15:00 - 18:00: Understanding the Impact of RAAS This chapter focuses on understanding the impact of the Renin-Angiotensin-Aldosterone System (RAAS) on the body. It begins by discussing the interaction between molecules that counterbalance one another, highlighting the importance of filtration slits in the process. These slits are size-based exclusion mechanisms that are regulated by podocytes. The chapter promises to delve deeper into these regulatory mechanisms in the following sections, setting the stage for a comprehensive exploration of RAAS's role in filtration and regulation processes in the body.
• 18:00 - 18:30: Summary and Conclusion The chapter discusses three layers related to capillaries and red blood cells. The narrator expresses dissatisfaction with using red as a pointer and opts for green instead. It specifically identifies the capillaries and red blood cells, focusing on the fenestrated layer.

Urinary System Part 3 Transcription

• 00:00 - 00:30 hello and welcome back for part three of our look at the urinary system where we are beginning to actually look at the process of producing and making the urine um and so uh we're going to go through that process right remember that this is really broken up into two main
• 00:30 - 01:00 processes all right process one is filtration and process two is reabsorption and secretion and the reason why I break these up into two different steps is because filtration is happening here within the renal corpuscle right whereas tubule reabsorption and tubule secretion is happening uh within
• 01:00 - 01:30 the proximal distal and the loop of Henley and so I'm dividing these processes up based off of location and where they are occurring and so what we're going to be looking at here is in this video here is the process of filtration and in the fourth video our last video we will go ahead and we will look at the processes of reabsorption and secretion
• 01:30 - 02:00 um once again I just want to kind of draw your attention to some key terminology that you need to be aware of oh this is going to not be good hold on a sec uh when we deal with the process of oh yeah no I can't do that oh hold on when we deal with the process of filtration
• 02:00 - 02:30 what we are really dealing with here is uh we're dealing with the movement of fluid from the cardiovascular system into the
• 02:30 - 03:00 capsular space and so that is filtration and what is produced production of filtrate now that is very different than the
• 03:00 - 03:30 processes of reabsorption and secretion right reabsorption is again the movement of fluid from
• 03:30 - 04:00 the tubule into the capillaries secretion again is the movement of fluid and by the way when I say fluid fluid let me just Define this real quick fluid here is the liquid component
• 04:00 - 04:30 Plus all soluble um materials all right so fluid here is defined as both not only the liquid not only the water aspect of it but also everything that is dissolved within the water that is moving across the membranes and so secretion uh once again here is
• 04:30 - 05:00 the movement of fluid the movement of fluid from the capillaries into the tubules all right so that sets us up with a little bit of understanding as far as what we are really looking at here and so this here is a really good diagram from the perspective of we see
• 05:00 - 05:30 that we have reabsorption we see that we have some secretion that is happening here within the loop of henle we are doing all reabsorption uh and then again in the distal convoluted tubule we are doing reabsorption and secretion primarily secretion um less emphasis on the reabsorption and then again in the um collecting duct we're again doing reabsorption and secretion more of an emphasis here on reabsorption all right
• 05:30 - 06:00 so more of a reabsorption in the proximal convoluted tubule on reabsorption more of an emphasis on secretion within the distal and more of an emphasis on reabsorption once again in the proximal I'm sorry within the collecting duct all right so let's start our look at this process of filtration
• 06:00 - 06:30 um oh is that what I wanted so filtration again movement of fluid and molecules from the capillaries of the glomerulus into the capsular space as we already defined but here's the Here's the the the the the trick to this all right the devil's always in the details as We Know um this movement of fluid this movement
• 06:30 - 07:00 of primarily water and the dissolved molecules the dissolved components of that isn't just moving from the capillaries isn't just moving from the glomerulus into the capsular space there's actually three layers that are separating the glomerulus from the capsular space we have these things called fenestrated capillaries we also
• 07:00 - 07:30 have a basement membrane and we have these things called filtration slits and each of these as we will discover here have very different functions what do I mean by that well they they tend to um selectively um exclude or allow things based off of very different criteria
• 07:30 - 08:00 right so fenestrated capillaries right fenestrated capillaries um they Intel they tend to exclude Things based off of size so in other words red blood cells and proteins tend to stay in the capillaries they're too large to pass through these fenestrated capillaries basement membranes tend to select
• 08:00 - 08:30 selectively exclude or allow things to pass across the membrane based off of electrical charge and so the membrane itself is negatively charged all right um so again things like albumin which tend
• 08:30 - 09:00 to be more negatively charged negative ions or negative molecules repel one another so albumin as a protein tends to not get past the basement membranes strictly because the fact that it's negatively charged and negative uh negatively charged molecules repel other negatively charged molecules now that's not to say that if it was uh small enough that it still wouldn't pass through albumin is also a rather large
• 09:00 - 09:30 molecule so both of those things counter one another um and then your filtration slits well these are um size based whether or not it excludes and the filtration slits are basically regulated by your podocytes and so we'll talk more about that here in a few moments all right so let's kind of go back and look at what the three
• 09:30 - 10:00 these three layers look like all right so this is what you're all looking at right here and so if we look here I get tired of red for a laser pointer let's see let's do green so if we look here right this here is your capillary these are your red blood cells that are coming down here all right this here this layer right here this is your fenestrated or your um
• 10:00 - 10:30 yeah your fenestrated uh slits or your fenestrated capillaries and so you can see here you've got openings within the membrane of the capillaries that are going to allow almost everything to go through right what it's excluding once again are red blood cells white blood cells uh plasma proteins all right proteins protein-bound minerals and hormones
• 10:30 - 11:00 basically anything that is larger than eight nanometers in diameter is going to get blocked all right and so these fenestrated capillaries this is not adjustable all right so this allows for a lot of things to go through and it's excluding things that are rather large in nature and then here you've got your basement membrane and once again this basement membrane is negatively charged and so
• 11:00 - 11:30 this is also uh blocking based off of charge now what's it allowing to go through well it's allowing things like water electrolytes glucose amino acids fatty acids vitamins urea uric acid creatinine all right um urea uric acid and creatinine are all metabolic waste products all right vitamins fatty acids amino acids glucose electrolytes and water are all things that the body needs and most
• 11:30 - 12:00 likely will end up reabsorbing later on but because we're regulating plasma volume all of these things are getting excluded from the plasma as water is moving because all of these things are dissolved within the water so all of these things pass through as solvent drag is dragging that water or is dragging those molecules and those other materials uh dissolved within the
• 12:00 - 12:30 water and then you have your podocytes these here are your filtration slits and so the area between the podocytes is the filtration slit so if these protocytes constrict they contract the filtration slits get bigger it allows for more
• 12:30 - 13:00 filtration it allows for more fluid to be pulled from the plasma if those podocytes are more relaxed these filtration slits are smaller and that's not allowing as much water and dissolved particles to leave the plasma so in other words
• 13:00 - 13:30 when the filtration slits is smaller the blood is retaining more fluid pressure remains higher in the capillary because not as much filtration is happening but when those protocytes are contracted and the filtration slits are larger then
• 13:30 - 14:00 the pressure is being decreased within the capillaries and that filtrate is flowing into the capsular space which is right here which is increasing the pressure within the capsular space some of you are probably wishing that I would write that down I can hear you thinking it and so because I can hear you thinking it I will do it
• 14:00 - 14:30 all right so um decreased filtration slits space leads to decreased filtrate production
• 14:30 - 15:00 it leads to um retainment of more plasma volume and it leads to um stable or increased
• 15:00 - 15:30 capillary pressure whereas increased filtration slit space will lead to
• 15:30 - 16:00 increased filtrate production it leads to decreased um plasma volume it leads to decreased
• 16:00 - 16:30 capillary pressure and it leads to an increased capsular space pressure all right is that making sense
• 16:30 - 17:00 okay it's a lot to digest so how do we regulate whether or not we are increasing that pressure or decreasing that pressure and what is what is normal well to understand this we have to go back and we have to visit um some of the things that we talked about that occurs within capillary beds during
• 17:00 - 17:30 the cardiovascular system so we've got to look at blood hydrostatic pressure and we've got to look at colloid osmotic pressure and we have to look at capsular pressure these are the exact same three things that we looked at when we talked about filtering blood or or reabsorption of waste products within capillary beds and the tissue the same thing we've just moved from capillary beds
• 17:30 - 18:00 within the tissue to a specialized capsillary a specialized capillary bed known as the glomerulus contained within the renal corpuscle and so same scenario is what we talked about before just a different location oops
• 18:00 - 18:30 and so what do we have going on in here well blood hydrostatic pressure that is the pressure within the glomerulus all right that is the pressure of the blood within the glomerulus so how much pressure is just the plasma volume itself applying to the wall of the glomerulus blood hydrostatic pressure equals
• 18:30 - 19:00 pressure of the plasma volume exerted on the wall of the glomerulus all right
• 19:00 - 19:30 that pressure remains high and this is a difference between what we talked about within the cardiovascular system and what we see within the urinary system because blood hydrostatic pressure remains High throughout the capillary bed we don't drop it we don't decrease that pressure like we saw within the capillary beds and and here's why you have a high rate of flow
• 19:30 - 20:00 in through the afferent arterial the afferent arterial has a wider diameter you allow for more blood flow in but look at the diameter of the effort arterial it's constricted so in other words we allow for a higher rate of flow into the glomerulus but we back that blood flow out
• 20:00 - 20:30 through the efforts by having a smaller diameter and what that does is that maintains high pressure throughout the glomerulus traffic is Flowing free and fast and all of a sudden you hit traffic and you slow down and the amount of cars I can get through a particular area is reduced
• 20:30 - 21:00 blood pressure blood is flowing fast and free comes through the glomerulus and the blood begins to back up because the efferent is constricted and so you maintain high pressure throughout the glomerulus approximately 60 millimeters of pressure forcing outward but you also have colloid osmotic pressure the amount of pressure applied
• 21:00 - 21:30 by the proteins and the large solutes that are in the plasma that cannot pass the fenestrated capillaries that cannot pass the basement membrane that cannot pass the filtration slits and so that calorie osmotic pressure is both the proteins I should say it is the proteins and the solutes in the blood remember that's creating its own
• 21:30 - 22:00 pressure 32 millimeters of mercury fighting against the 60 millimeters of mercury forcing outward and you have cap sular pressure in other words as this capsular space fills with filtrate it applies pressure onto the glomerulus
• 22:00 - 22:30 the more the capsular space fills the more pressure is exerted on the glomerulus the less filtering is going to occur and so your net filtration rates your net filtration rate or your net filtration pressure your NFP is 10 millimeters of mercury out and that is maintained
• 22:30 - 23:00 throughout the glomerulus blood hydrostatic pressure remains higher throughout the system and the whole premise of this is you want to conduct filtration through the entire glomerulus if
• 23:00 - 23:30 blood hydrostatic pressure was allowed to drop what would begin to happen inside of the capsular space you'd start reabsorption you would start reabsorbing everything that you just got rid of you don't want that to happen you want to block you want to prevent you want to inhibit reabsorption in the renal corpuscle
• 23:30 - 24:00 and so you have to maintain higher blood hydrostatic pressure through the glomerulus and in doing so you maintain filtration throughout this is a video I'm not going to play the video now but you've got this slide here and that will review for you glomerular filtration
• 24:00 - 24:30 the rate of filtration is equal to um net filtration pressure is equal to about 12.5 milliliters of filtrate per minute
• 24:30 - 25:00 and so that is what is uh that is what we are maintaining within the renal corpuscle we are maintaining this rate of about producing about 12 and a half milliliters of filtrate per minute all right by keeping that osmotic pressure and the blood hydrostatic pressure where it is so um all right regulation right how do we regulate and maintain
• 25:00 - 25:30 that high rate of flow in and that low rate of flow out well this is where the juxtaglomerular apparatus comes into play so there is something referred to as tubule glomerular feedback in other words tubular glomerular the tubular part is the capillaries the capillaries that
• 25:30 - 26:00 it's flowing through the glomerulus that pressure is being constantly monitored and it's being monitored in the afferent arterial and the efferent arterial through what we refer to as the juxtaglomerular apparatus and so it's regulating and sensing and monitoring changes in pressure and fluid composition all right and it's doing that again
• 26:00 - 26:30 primarily on the afference but also to some degree on the effort and so uh what you're seeing right here is that scenario of the juxta glomerular apparatus so here's the afferent arterial coming into the glomerulus here's the efferent arterial heading out right here
• 26:30 - 27:00 are those JG cells on the afferent arterial there are also JG cells on the efferent arterial and these JG cells are monitoring pressure they're monitoring primarily pressure all right um if there is higher pressure coming into the uh afferent arterial that means you have higher plasma volume
• 27:00 - 27:30 and so you are going to increase the rate of filtration in the glomerulus how do you do that well you vasodilate on the afferent uvasoconstrict on the effort what does that do that slows the rates by which the blood is flowing through the glomerulus and allows for more
• 27:30 - 28:00 filtration more filtrate equals reduced blood volume and plasma volume which decreases blood pressure if your blood pressure is low your JG cells will detect that and when they detect that drop in pressure the afferent will constrict vasoconstrict the efferent can actually vasodilate a little bit and that allows
• 28:00 - 28:30 for the blood to flow quicker less filtrate is produced less filtrate is produced a lot of this is regulated through the sympathetic nervous system all right um and so during exercise your sympathetic nervous system is kicked up which means you want to go ahead and decrease the the rate at which you are
• 28:30 - 29:00 producing filtrate because you don't want to have to stop and have to use the bathroom and so you constrict the afferent arterial which diverts the blood back into the cardiovascular system to support the muscular tissue and the nervous tissue and um other tissues skeletal muscle tissue that you're going to need in order to support whatever that sympathetic activity is and so for example during exercise you constrict the afferent
• 29:00 - 29:30 arterioles this reduces the glomerular filtration rates which reduces urine production and so that way you're supporting sympathetic activity during parasympathetic activity the opposite would happen right you're going to go ahead and vasodilate that afferent which is going to increase glomerular filtration rate which is going to increase the rate of production of the filtrate um so that way you can again regulate
• 29:30 - 30:00 plasma level blood pressure blood composition pH balance we're going to find out is also regulated through here um and this is where we end and this is where we come into and we're almost done here we're almost done here this is where we come into our Raz mechanism our renin Angiotensin
• 30:00 - 30:30 aldosterone system and so let's kind of look at this here all right I'll try to make this as painless as I can follow my little schematic that I have over here and nobody will get hurt I promise and so what ends up happening here is we start the process right here with the kidney all right now in this scenario we're going to start with the assumption that there is a drop in blood pressure
• 30:30 - 31:00 all right so blood pressure is detected as dropping in those JG cells and the JG cells um is going to go ahead and secrete renin renin is then going to mix if you would with an enzyme that is being secreted from the liver now the liver is always producing
• 31:00 - 31:30 angiotensinogen all right the liver is always producing through um there's always producing angiotensinogen the difference is angiotensinogen is inactive in its initial form it is not activated until renin is released so renin Cleaves or renin shortens angiotensinogen right it's what's going
• 31:30 - 32:00 to allow it to be active well renin is not always available why because blood pressure is usually stabilized but if we if we detect in the JG cells in the juxtaglomerular cells they drop in pressure coming through the afferent arterial those JG cells are going to secrete renin which is going to cleave angiotensinogen and that creates Angiotensin one
• 32:00 - 32:30 Angiotensin one is then going to be cleaved by another enzyme called Angiotensin converting enzyme Ace and that is produced in the lungs now let's think about this the lungs play a critical role in maintaining blood pressure yes we can agree to that yes hopefully all right so if you need if you have
• 32:30 - 33:00 higher cardiac output you have more blood being delivered to the lungs your lungs are functioning at a higher rate right so if your lungs are detecting an increase in blood pressure everything's good but if the the cardiac output decreases the rate of flow to the lungs decreases the lungs start to say crap I've got decreased blood flow coming to
• 33:00 - 33:30 me blood pressure is dropping and so the lungs detect the drop in blood pressure and they secrete Ace they secrete the Angiotensin converting enzyme which Cleaves Angiotensin one notice this is a this is a a scenario of um backup all right so just the lungs detecting a drop in blood pressure
• 33:30 - 34:00 isn't enough both the lungs and the kidneys have to detect this change in blood pressure they have to detect this drop in blood pressure because just releasing Ace isn't going to do anything to angiotensinogen renin is going to act on angiotensinogen creating Angiotensin one ace is going to only act on Angiotensin 1 creating
• 34:00 - 34:30 Angiotensin II and what does Angiotensin to do in order to increase blood pressure well it's going to cause vasoconstriction within the arterioles Angiotensin II is going to tell the hypothalamus to initiate the thirst complex
• 34:30 - 35:00 it's going to make you drink hopefully water because that's water is going to quickly be absorbed in the duodenum and in the jejunum into the cardiovascular system to increase blood plasma plasma levels to increase that blood pressure and Angiotensin 2 is going to communicate with the adrenal gland Within the Zona glomerulosa the Zona
• 35:00 - 35:30 glomerulosis notice the connection there to secrete aldosterone and aldosterone is going to act on the distal convoluted tubule to increase water reabsorption from the filtrate we actually increase salt reabsorption
• 35:30 - 36:00 now the other thing that will happen here is angiotensinogen 2 will block the release of antidiuretic I'm sorry it will initiate it will initiate the release of antidiuretic hormone so Angiotensin II also stimulates the
• 36:00 - 36:30 pituitary gland to secrete ADH which is going to reabsorb even more water and it's going to do that through the distal convoluted tubule aldosterone is going to act primarily on the loop of henle to reabsorb Salt which is going to force the reabsorption of more water Angiotensin II is going to act on the pituitary gland to secrete ADH which is going to act on the distal convoluted tubule to go ahead and reabsorb more water it's going to act on the
• 36:30 - 37:00 hypothalamus to initiate thirst so you're drinking more and it's going to cause vasoconstriction all of this too raise the blood pressure back up I know I've said this before this is why when you drink excessive amounts of alcohol alcohol inhibits ADH
• 37:00 - 37:30 which means it promotes Phil it promotes higher water release you urinate more which dehydrates you which causes the headache and The Hangover but that's Razz that's the renin Angiotensin aldosterone system all right
• 37:30 - 38:00 JG cells detect a drop in blood pressure release is renin which goes ahead and Cleaves angiotensinogen produced by the liver which is always being produced by the liver Cleaves into Angiotensin 1 which is then cleaved by Ace released by the lungs because the lungs have detected a drop in blood pressure creating Angiotensin II Angiotensin II is the active form
• 38:00 - 38:30 that is going to initiate the emergency response to increase blood pressure by initiating the third streak The Thirst response drinking water to increase plasma levels it's going to cause vasoconstriction to go ahead and create more resistance in the arterials to increase blood pressure it's going to initiate the release of aldosterone for salt retention to go ahead and absorb more water along the loop of henle and it's going to stimulate the pituitary
• 38:30 - 39:00 gland to secrete ADH antidiuretic hormone which is going to act on the distal convoluted tubules to reabsorb even more water holy poop that's a lot make sure you understand that I like to put this on the exam now there is a video there that is going to really uh kind of summarize that for you pay attention to it please
• 39:00 - 39:30 and um here is a nice little summary table of everything that is happening when we talk about glomerular filtration regulation in the production of filtrates and I have kept you for 40 minutes um this is a little bit longer of a video but there is a lot to go over when we talk about filtration and so I'm going to give you some time to digest this to analyze this to answer some questions and to ask questions
• 39:30 - 40:00 and with that I shall see you on the flip side