welcome back welcome back welcome back to science all right so in our final segment we're going to talk about big picture stuff and that's going to help um a lot because we've been kind of in the details of it which is complicated at times so uh It lines up a little bit and goes more anatomical than physiological so urine forms uh throughout the process of nephrons collecting ducks and eventually it's going to enter to the arena populate it's going to go to minor calyces major calyces renal pelvis now it's going to now funnel into the ureter that's going to go to the urinary bladder and then out through the urethra so let's talk about those structures the ureters the ureters are going to be those long like tubes that are going to have going from the kidneys all the way down so tubular organs about 25 centimeters long transports urine from the kidneys to the bladder that's her ureters they begin at the renal pelvis of the kidney so imagine the kidney and then off the renal pelvis kind of that point as it travels down to the urinary bladder and so this big this is going to empty into the posterior portion of the urinary bladder so urinary bladder is going to have its own structure and it's going to have inputs coming into both of these sides emptying into the urinary bladder at the bottom side of the urinary bladder you're going to have the urethra coming off that so the urinary bladder so when you look at a ureter it's going to have a mucosal coat that's going to be on the inside it's going to be made of the transitional epithelium we also have a mucosal excuse me a muscular layer it's going to go through peristalsis and then you're going to have a fibrous coat which is going to help anchor it into location so the peristaltic waves are going to help move the urine just naturally through occasionally there are obstructions that happen and these are ones that we typically call kidney stones renal calculi or renal calculus strong peristaltic waves are going to be used to help move the material through the stone towards the bladder this is quite painful quite painful it's said that this is the only thing that I've heard that is more painful than childbirth and I'll take your word for it on either one I would rather not endure the pain it sounds absolutely horrible so childbirth too I'm sorry guys if you had a kid I mean I love kids and I love my own kids and I'm so grateful that my wife did that for us and for them all right so let's get on a different thing so the utero renal reflex so this is going to consist of the renal arterials and decreased urine production by the affected kidney so let's say that you have a blockage instead of having like continual buildup and eventually kidney failure or rupturing of your ureter into your abdominal cavity the ureteral renal reflex is basically going to have that feedback like we got a blockage here let's reduce function on this side and so that's going to have reduced function of the affected kidney and it's going to allow for the other one to do essentially more of the work so looking at the ureter you have the innermost layer which is going to be that transitional epithelium that's going to be on the mucosal layer then we have the peristaltic waves that can occur with the muscularis then the outside we have the fibrous connective piece chronic glomerulonephritis this is inflammation of the glomerular capillaries Progressive degenerative disease with no cure already horrible so symptoms hypertension protein protein ureas this is referring to there is protein that actually is moving across into your urine no matter urea this is referring to blood in urine urine is typically going to be dark in color going to have elevated blood levels of the blood urea nitrogen and creatine and decreased protein in the blood I mean since we're dumping protein you're going to have less that's there so this can lead to end-stage renal disease treatments for this once again no cure other than a transplant you have hemodialysis three times a week is the best option if a kidney transplant is not an option so kidney stones so they can be composed of a few different things one is uric acid one calcium oxalate calcium phosphate or Magnesium phosphate so form in the collecting ducts or the renal pelvis of the kidney these cause severe pain nausea vomiting blood neuron as it's tearing the inside of the ureter sixty percent of kidney stones pass on their own and others can be shattered with lithoshrippy or removed surgically so all of these can be very very painful and this is busting it up uh with ultrasonic waves and a smaller like cinder-sized opposed to Peak gravel sized all right so the tendency to form Stones a lot of that's genetic so if you have well my mom and dad had it I got bad news um you're going to have a higher probability of developing these calcium stones so the cause you have different calcium supplements that affect people that are inheriting this excess vitamin D urinary tract blockage urinary tract infections due to that blockage so let's talk about further structures the urinary bladder this is going to be a hollow distemble tube so things that are distendable that means that they can swell and move oftentimes they have these Rouge within those are curvatures um this is going to stir store urine that's going to then send it into the urethra it's going to have its different components as well it's going to have two ureters flowing in those are going to and one urethra flowing out that's going to form this one two three different points of contact this is going to form What's called the Trigon the uppermost part where the ureters are going to be on the top and the urethra is going to be on the bottom and so that's going to have a natural tendency to funnel it by gravity to flow downward so it consists of four layers there's an inner mucosal coat that's going to have the mucosa and transitional epithelium a submucosal coat a muscularis coat a muscular coat and also the outer serous coat for connectivity so smooth muscle fibers are going to make up the muscle part and it's going to have some different muscles inside of this so one of these is going to be called the detrusor muscle the internal urethra sphincter so sphincter once again is a circular muscle and this is going to be around the neck of the bladder so this is the location of the urinary bladder and here is the uterus this is a woman cross section and you can see by location if the baby is growing here and we're not pregnant talking about pregnancy right now we will talk about this eventually but the mass of the baby is going to cause the size of the urinary bladder to feel smaller and so a person would micturate p and they would produce very small volumes even though they feel like they've really got to go and you know be equivalent to when you feel like you've really got to go whenever you're not pregnant and the amount of urine that you would produce just volumes and volumes and volumes and then whenever you're pregnant you have to go and you like I barely can make it and then you get and you go and you produce just a little and you want to like that's all that's all ah so yeah it's due to the change and the size capacity and those stress receptors are still the same stretch receptors as they're going to have those uh movement all right here's a cross section of just the bladder you can see the bladder is a little bit different due to the location of the different reproductive structures that are going to be there so here's a cross section of this and you can see Within there's this muscular structure that's around it this is the detrusor muscle also as you get down to this region right at that neck region you're going to get into this internal urethral sphincter and so this is involuntary this is going to keep a person from accidentally wetting themselves um on the regular this is once again is a male and so this is the prostate and mention um as mentioned earlier that there's three different regions that are going to be with the male when we're starting to talk about the urethra and so this is going to be the prostate that the urethra is essentially think of it as um trying to think of a good analogy let's say that a bolt a bolt would be the metal of the boat would represent the prostate and the hole within the bolt would represent that your uh that urethra that's going to be flowing through there so here's the prostate you can see that it's going to completely Encompass around the urethra all right so the urethra is a tubular organ that can it's going to convey the urine from the urinary bladder to the outside of the body there are different layers here the innermost is the mucosa coat and a thick muscular coat it's going to have the internal urethra sphincter which we've mentioned and shown and then we also have and once again it is involuntary and then you have the external urethra sphincter this is voluntary so whenever you feel like you have to pee and they say hold it hold it um that you holding your urine in by choice that is your external urethral sphincter that is actually that circular muscle that we are keeping close to keep the urine from flowing past it all right so different layers we have the sub mucosa layer that has the glands mucous glands and also called the urethral gland so the female urethra is about four centimeters long its location is going to be the external urethral orifice and it is anterior to the vaginal opening so if we look at this structure we have the urethra that's about four centimeters there and vaginal opening is here so that's one opening and you can see this is going to be a very small opening that's going to be a little bit further up and so that is going to be the urethra opening that is there all right male urethra is going to be an average of 19.5 centimeters long and so this is going to have dual function both in urination and reproduction this tube is going to be used in delivering the sperm as well what we can say the seminal content but also for urine it's going to have a different um essentially a valve that's going to allow for Reproductive cells to flow through or urine to flow through and we'll look at that when we looked at later in chapter 22 I believe when we look at reproductive organs all right so the male has three different sections to his urethra has the prostatic urethra that's the one that we looked at that's going to have the prostate essentially and companies seeing all around it the membranous urethra and also the spongy urethra so the sponge or urethra is going to terminate at the external orifice in the penis so here you have the movement this is female this is male so you can see to this point is essentially similar you don't have the prostate urethra instead you just have what we call the urethra but at this point this is our external urethral sphincter whenever you're trying to not pee and here we have the penis that's after that still continuing the spongy urethra through there all right urination is officially called micturation This is the expulsion of urine from the urinary bladder you're in leaves urinary bladder through the micturation or reflex so this occurs through reflex contraction of the detrusor muscle which we know is part of the urinary bladder and the reflex relaxation of the internal urethral sphincter so that is the involuntary part is the internal urethra sphincter now it's also going to require the relaxation of the external urethral sphincter that is the one that we are in charge of that is voluntary we are causing that to be contracted or um relaxed so urinary bladder May hold as much as 600 milliliters the urge to start to to urinate will start at about 150 milliliters this is going to be controlled by the micturation reflex center and the sacral spinal cord so problems with micturition incontinence this is the inability to control make duration and nocturnal anurescence this is referring to bed wetting oftentimes um this is really common in children and it's not super uncommon with adults but it's something that just occurs and it's more at night hence the name nocturnal all right so these are major events in micturition kind of an overview a cliff notes of what we looked at and here are different kinds of Developmental abnormalities of the urinary system so quite diverse and what they're affecting you can look through and look at each one of those all right your analysis this is the taking of a urine sample and this can be used diagnose disorders or disease or even check for drug usage for example people with untreated diabetes mellitus has glucose in their urine and they have several harmful inherited disorders that alter the color of the urine sometimes even the viscosity of it causing it to be very thick certain genetic conditions alter urine without harm like beat urea beat urea is going to be when a person eats beats their urine turns pink kind of interesting huh and you also have urinary excretion of the odoriferous component of asparagus some people do that and whenever they eat asparagus it produces such a bad odor that they really don't like asparagus and that's a shame because I think asparagus are delicious all right so the urinary system has sufficient Reserve in both structure and function to mask age-related changes kidneys become slower to remove nitrogenous waste and Toxin and to compensate for changes and that maintain homeostasis age-related changes canoes appear scarred and grainy due to connective tissue accumulation kidney cells dies by the age of 80. the kidneys have lost a third of their Mass kidney shrinkage is due to loss of glomerulite loss of the surface area for for filtration decreases the glomerular filtration rate to about half by age 75. protea May develop renal tubules thicken reabsorption of nutrients and ions become less efficient harder for the kidneys to clear certain substances blood flow to the kidney slows urinary bladder ureter and urethra loses elasticity a hints depends uh bladder holds less urine kidneys are less able to activate vitamin D and the loss of bladder control may result in incontinence all right guys that's going to end it for the urinary system all right so long