 Hello everybody. So today we're going to talk about the anatomy of the urinary system. The urinary system, the primary organ of the urinary system is the kidney. And its purpose, the system's purpose, is to filter the blood and remove harmful substances. If you think about it, you are essentially a walking bag of saltwater. And there's so much stuff going on in your body that that saltwater sometimes gets dirty. And when the saltwater gets dirty, it cannot function. Your cells cannot function properly. So the purpose of the kidney is to help clean the dirty saltwater and also to make sure that the saltwater is the correct concentration. There are a whole bunch of ions in your blood and in your interstitial fluid which is surrounding all of your cells. There are a whole bunch of really important ions that if they're not in the correct concentration you begin to malfunction fast. So things like hydrogen ions, maybe I'll just start making a list, hydrogen ions, these are different substances that your kidneys help maintain the concentration of in your blood. Hydrogen ions are the what? Ion that causes your blood to be acidic. So the more hydrogen ions you find in your blood, the more acidic your blood is. Those of you who have had me for BiO1 know that if we combine hydrogen ions with proteins, we can actually curdle or turn those proteins, denature those proteins and turn them into mashed potatoes. And if that happens in your blood, your blood isn't going to flow very properly. That's going to be a bad thing. So maintaining hydrogen ion concentration is really important. Another ion that's important to maintain is HCO3. That's a bicarbonate ion. And bicarbonate ions tend to make substances basic. Similar, if your blood becomes too basic, your cells stop functioning properly. Sodium ions, potassium ions, calcium ions, all of these substances are important to regulate in proper concentrations in the blood. And the kidneys play a role in that. So in addition to monitoring ion concentrations, your kidneys also, they clean. Did I already tell you that you're basically a bag of salt water? Here are all the salts that are in your bag. But you, as your cells metabolize nutrients to make energy, they produce waste products like carbon dioxide, which gets into the blood. And if we left it there, you would turn into an acidic bag of mashed potatoes. So we actually, through the process of breathing and removing carbon dioxide from your bloodstream, you actually can help maintain your your pH balance. That's physio. No worries. We'll go over that in way more detail next semester. Or dude, you can just go hunt down the physio lectures because there's a bunch of them here. And you can get a little preview of the physio involved. So essentially, we want to keep our water clean, our salty water that we are clean, and the correct concentration. If you think about like something like a fish or a sea anemone, or even a sea monkey, I have a sad sea monkey tale that I can tell you about my small child's sea monkey crew and sea monkeys are brain shrimp. So they actually live in salt water. So part of that stuff that you add in that has all the sea monkey eggs in it actually has salt in there as well. And so my children grew sea monkeys and they were really proud and they had a whole bunch of them. They'd lived for a really long time like six months. They've had these sea monkeys. And then it was not my fault. We were up examining the sea monkeys and the container of six month old sea monkeys fell on the ground. Well, we rescued as many sea monkeys as we could from the pile upon the ground and then added water. What is wrong with this picture? Well, we didn't add salt water in the right concentration. And so all the sea monkeys exploded. Yeah, it was it was a little bit traumatic in our household. But the reason why they exploded is because all the water, they needed salt water in order to have the water not go into their bodies and cause them to explode. And that's osmosis. And that is a very important phenomenon. Your cells will explode if they are not surrounded by the proper concentration of fluid around them. So kidneys, are they important? Dude, so important. And now let's look at the actual anatomy of the kidney itself. I'll be right back.