HUMAN EXCRETORY SYSTEM Made Easy - Human Urinary System Simple Lesson

hello and welcome to med simplified the human excretory system is one of the most important organ systems of the body that performs the vital function of filtering your blood and removing excessive and unnecessary materials from the body this helps to maintain an internal chemical homeostasis and prevent damage to the body in this video we are going to study about the human excretory system in a narrow sense the term refers to the urinary system however as excretion involves several other organs it is important to remember that human excretory system is a wide term that also includes organs like skin lungs gut nails and hair in this video we will first learn about the urinary system and then we will discuss about the other organs that are involved in the process of excretion before beginning if you are new to this channel make sure to click on the subscribe button below to get all the upcoming scribe educational videos and also if you find the content of this channel helpful you can now support med simplified on patreon.com for the price of a coffee cup that will allow me to make more free educational videos like this all the links are in the description below and for more information watch till the end of this video so let's begin with the urinary system the urinary system consists of a pair of kidneys a pair of ureters a urinary bladder and a urethra the renal artery supplies the kidney with fresh blood while the renal vein drains the blood from the kidneys we'll go through each of these structures one by one and understand their role in the process of excretion so the main hero of the urinary system is this pair of kidneys the kidneys do the main job of filtering your blood and removing all the waste substances from it the rest of the urinary system is basically just a storage unit and provides a mechanical force so that the urine can be expelled from the body now the kidneys are bean shaped organs that are present on each side of our spine almost at the level of our umbilicus if you take a look at this specimen you can note the position of kidneys in the body i know it's gross but have a look this is a cut section of the body and you're looking at it from the top angle this is the front side of the body and this is the rear here is your amplicus and this is your spine and here you can note the position of the kidneys in the body you can clearly see that the kidneys are actually present towards the rear or the posterior aspect of the abdomen so each kidney measures approximately 11 to 13 centimeters in length with the left kidney being slightly larger the right kidney is placed at a lower level as compared to the left kidney this asymmetry in size and placement is due to the position of liver on the right side of the body now each kidney has a convex and a concave border the concave border of the kidney has this notch-like structure known as the hilum this is the place where the blood vessels enter and leave the kidney now if we slice the kidney with a knife in this manner we will able to see this internal structure of the kidney the first thing you should note here is that the internal structure of the kidney is divided into two major regions the renal cortex and the renal medulla the renal cortex is this outer region of the kidney while the renal medulla consists of these 12 to 15 cone-shaped structures known as the medullary pyramids the outer renal cortex runs in a continuous manner with a number of projections that extend down between the pyramids guys you can get the handwritten lecture handout from this video by joining our channel click the join button below to get the lecture handout from this video as well as our previous videos now like i told you this is known as the hilum of the kidney the point where the blood vessels enter and leave the kidney the blood enters the kidney through the renal artery after the renal artery enters the kidney it gets divided into many small branches these small branches ultimately go to the cortex area and divide into many smaller branches known as capillaries now the cortex region contains the most number of nephrons in the kidney the nephron is the basic functional unit of the kidney and each kidney contains approximately one million nephrons this is the main structure that filters the blood in the kidney now if you want to learn in detail about the structure of nephron and the mechanism of urine formation check out our this video on the structure of nephron links are in the description below now let's continue with our basic structure so we reached a point where the renal artery has entered the kidney and divided into many smaller branches which ultimately divided into minute branches known as capillaries each of these capillaries enter the nephron and form a tuft of blood vessels in this cup shaped structure known as the bowman's capsule and it is in this cup shape structure that the filtration of blood takes place here you can see in a magnified view how the capillary enters the nephron and forms a tuft of blood vessels that filters the blood the blood enters the nephron through this vessel and leaves it via this vessel the waste products and water leave the blood into the nephron and the pure blood exits through this blood vessel all of this pure blood comes out of the kidney through small blood vessels which ultimately drain into the renal vein so this stuff was happening right here in the nephron all the filtered stuff is passed down into this small tube-like structure now see how urine is formed here if you look at this illustration you can note how a single nephron is placed inside the kidney the waste metabolic products and water that is filtered by the nephrons enters the medulla of the kidney through small ducts known as the collecting ducts all these collecting ducts converge at the tip of the renal medulla which is known as the papilla these collecting ducts drain the waste products and water into this central dilated part of the kidney which is known as a renal calyx now what does this word calyx mean well if you remember calyx is actually a part of a flower this is known as the calyx of a flower if you look at the shape of a calyx of a flower you can see why this part of the kidney is known as the renal calyx the renal calyx receives the urine from each of the renal medullary pyramid and ultimately drains all of this urine into the ureter so moving forward with the structure of the urinary system the urine that is formed in the kidneys is passed down with the help of these structures which are known as the ureters uraters are 25 to 30 centimeter long tubes that exit the kidney through the hilum and they run down into the urinary platter the walls of the ureters have smooth muscles in them that help to propel the urine forward from the kidneys into the urinary bladder now a kidney stone can move from the kidney and become lodged inside the ureter which can block the flow of urine as well as cause a sharp cramp like pain in the back side or the lower abdomen this type of pain is known as a renal colic next the urine moves from the ureters into the urinary platter the urinary bladder is a hollow organ that is present in the pelvis the wall of the urinary bladder is a muscular wall and it is a distensible structure meaning it can stretch now a typical human bladder will hold between 300 to 500 milliliters of urine before the urge to empty occurs but it can hold considerably more if you don't find a place to pee immediately the urine enters the bladder through two ureters and leaves the bladder through the urethra which is another tube-like structure that we will discuss in just a bit now this part of the bladder is known as the body of the bladder and the part below it is known as the neck of the bladder the neck of the bladder is very important it is basically this part of the bladder that make sure that you don't leak urine all the time the neck of the bladder contains a ring of smooth muscles that remains contracted and keeps the opening of the bladder closed whenever we want to pass urine the nerve supplying the neck of the bladder relaxes the smooth muscles here which allows the urine to pass from the bladder into the urethra this ring of smooth muscles is known as a sphincter of the bladder so our kidneys keep producing urine which is carried by the ureters into the urinary platter the urinary bladder provides two important functions for the urinary system first it provides a hollow organ that is used to store urine this is a very important function because you can imagine what running for the toilet every 10 minutes would look like second the urinary bladder is a muscular organ the contractions of the muscles in the wall of the bladder provide the force by which urine is expelled through the body the urine exits the bladder through the urethra urethra is another hollow tube-like structure that helps to expel the urine out of the body as the passage needs to traverse the length of the penis it is significantly longer in males than females it is approximately 4 centimeter in length for females whereas it is about 20 centimeters in length in the male body this is the reason why females have urinary tract infections more frequent than men besides excretion the kidney has many other important roles like maintaining a proper volume of fluids in the body maintaining a proper balance between the levels of different types of ions in our body maintaining a proper ph of the body regulation of the blood pressure and formation of important vitamins like vitamin d so this was about the role of urinary system in the process of excretion now let's talk about the rest of the organs of the body that are included in the human excretory system and the first one of them is your skin sweat glands in the skin secrete a fluid waste called sweat or perspiration however its primary function is temperature control and pheromone release therefore its role as a part of excretory system is minimal sweating also maintains a level of salt in the body sweat is mostly water dissolved in the water are trace amounts of minerals lactic acids and urea many other trace elements are also excreted in sweat like chromium copper nickel zinc and lead the large intestines main function is to transport food particles through the body and expel the indigestible parts at the other end but it also collects waste from throughout the body the typical brown color of mammal waste is due to bilirubin a breakdown product of normal heme catabolism at about 10 feet long in humans it transports a waste through the tubes to be excreted the respiratory system also plays a role in the process of excretion as lungs expel out gaseous waste like carbon dioxide the liver is an important organ that helps in excretion of many drugs liver metabolizes these drugs and their waste products are passed into bile the yellowish liquid that is formed in the liver and delivered to the small intestine it is through this bile that the liver excretes many waste products like metabolites of drugs and heavy metals apart from these nails and hair are also considered a part of the excretory system as many heavy metals are excreted in the nails and hair now like we discussed previously in this video for you to have a complete understanding about the process of urine formation and the function of kidney you need to watch this video about the structure and function of nephron this video explains in detail about the structure of nephron and how urine is formed inside the kidneys i hope you like this video thank you so much for watching

Channel: MEDSimplified

Views: 671,045

Keywords: human excretory system, urinary system, urinary system anatomy and physiology, renal, kidney, bladder, urine, biology, tutorial, how is urine formed, how is urine made in the human body, how is urine made, how does kidney work, animation, easy, simple, class 10, class 12, renal pelvis, kidney anatomy

Id: W1fw2qQ9Syo

Length: 14min 3sec (843 seconds)

Published: Mon Feb 10 2020