I think it's important that we're talking about the liver, gallbladder, and pancreas. These are not organs that necessarily are associated with EOE, but I think it's an important investment in terms of learning about the GI tract, more than just the esophagus, right? Your job, in addition to taking care of patients with EOE, is to also have a better understanding of the entire GI tract and how they kind of interact with each other, all right? So we'll talk about the liver, gallbladder, and pancreas in health. So we talked about the gastrointestinal tract, right? So Dr. Lightdale mentioned that when you eat, right, the tract itself is from your mouth to your anus, right? It's one long tube. The food goes down your esophagus, the stomach, the small intestine to the colon. And then there's some other organs in the GI tract, the liver, gallbladder, and pancreas that contribute to this tract, okay? And one of the fascinations I had with GI and the reason why I went into GI in medical school is because there are so many organs here, right? Like say, the heart, cardiology is one organ, the pulmonary, the lungs is one organ, right? The GI tract's got a lot of different organs and they all interact together to help you digest your food. All right, so let's talk about the liver. So it's considered a vital organ, meaning if you don't have it, you die, all right? So you have to get a liver transplant if your liver gets really sick, otherwise you can't live. It's located up in the right upper quadrant, so on the right side of your belly, all right? It's mostly tucked underneath the ribs, it's kind of protected, but you can feel the edge of the liver sometimes if you're laying down and taking a deep breath. It weighs about three to four pounds and there's two blood supplies to the liver, which is a little unique. We'll go into that, the hepatic artery and the portal vein. All right, so this is the anatomy of the liver. We'll go into this in a little bit more detail, but there are again two blood supplies. The portal vein at the bottom is what draws all the blood from your, essentially from your body. It goes into the portal vein, gets cleaned by the liver, all right? And then the liver sends the blood up back to the hepatic veins, it goes up to your heart and it gets pumped the rest of your body, right? But the liver does an important job of cleaning all your blood and that's why all the blood supply has to get through the liver at some point to get cleaned out. The other blood supply to the liver is the hepatic artery, that's the red vessel there in the liver. And then you can see this green duct, we'll talk more about that too, this is the bile ducts and the gallbladder and you can see how they enter and meet into the small intestine of the duodenum, which was mentioned in the previous lecture. All right, so this is the biliary anatomy. So the bile ducts are located within the liver and we sometimes call this the biliary tree, right? Explain to patients, it looks like a tree. The trunk of the tree is the biggest, that's the common bile duct and as you go up into the liver, the duct should get smaller, right? It's like a typical tree. And so there are diseases of the bile ducts in the liver in which the bile ducts don't look like this, right? Instead of getting smaller and smaller as you go up, they get bigger, smaller, bigger, smaller and that's a problem because bile can't flow through the liver as it's supposed to. You'll see that there's this gallbladder over there to the right or the left of the screen but on the right side of the body, right? So the bile that's made by liver gets stored in the gallbladder, okay? And then when you eat, the gallbladder squeezes and bile comes out of the gallbladder and down through the bile duct into your small intestine, right? And you may have heard of plenty of people, maybe your friends or family members have had their gallbladder removed, okay? That's the most common abdominal surgery done in this country. You don't need your gallbladder because it doesn't do anything except store bile, doesn't make bile, right? The liver you need because it makes bile, you need bile to break down your food but the gallbladder doesn't make anything. It just stores it and concentrates your bile. You don't really need it for real purposes, right? So you can live without your gallbladder, no big deal. And everything drains through this little opening called the ampulla which is in the duodenum. All right, so here are some functions of the liver and the bile ducts, right? So the liver produces bile as I mentioned and then bile is then stored in the gallbladder. So the bile is released in response to meals via a hormone called CCK or cholecystokinin. So again, the bile gets stored there and then when you eat, what's pretty cool is that your gallbladder squeezes and then bile comes down through the bile duct, down through the ampulla and then into your small intestine. And bile is important for absorbing fat as well as fat-soluble vitamins including A, D, E, and K, all right? So the liver has a lot of functions, right? Because I mentioned it's a vital organ so if you don't have the liver, you got a lot of problems. And so it makes a lot of different things. One, it makes clotting factor so that's what allows your blood to clot, right? So when patients with liver failure, their blood doesn't clot very well. They tend to bleed a lot and if they have a bleeding event, they tend to bleed a lot more than usual because they can't clot and stop the bleeding. It regulates glucose to some extent or your sugar, right? It stores sugar and when you're starving, it makes sugar for your body to have when you need energy. It makes and breaks down proteins. It's also responsible for cholesterol. It also has a number of storage functions. So it stores glucose in the form of glycogen. It stores a bunch of vitamins along with iron and copper. These are some of the minerals and vitamins that you need that are essential for life and that your liver is responsible for holding on to and releasing when you need it. I love how some of you guys are like furiously writing down notes. That's great, all right? I give a lot of talks now and most people don't even take notes anymore. They take their phones out and just take pictures of every slide and I used to do that and then I realized I never looked at them again, all right? And as you write it down, like you reference a notebook. So I love how you guys got little notepads to write on because I don't find that taking pictures is that helpful. You look at pictures of your kids or your friends but not of old slides. All right, and so it also has an important function of breaking down things, right? So it breaks down medications, drugs, alcohol. So if you guys had a drink last night or are going to have some drinks tonight, your liver is responsible for breaking that down, all right? Along with other toxins including chemotherapy for patients with cancer, the liver breaks that down. So if your liver is not working, you can't get chemotherapy oftentimes. So the liver plays an essential role in breaking down these things you ingest. All right, so before I go on, any questions about the liver and the bile ducts? This is a fairly quick lecture. Go ahead. On ultrasounds, can you explain why it's so common to see like cysts on livers but they say, oh, it's no big deal? Yeah, so this has to get into the pathology and things that are, you know, dangerous to you or not. So cysts in the liver are very common, particularly as you get older. They're much more common. They're completely benign, so we don't typically worry about them. You get cysts in the kidneys, the ovaries. No one really worries about these things because they're, for the most part, benign. Sometimes they get really, really large and they cause symptoms, then something needs to be done about it. But I'd say about 99% of the cysts you see incidentally on imaging, whether it be ultrasounds, CT scans, MRIs, nothing needs to be done about them. They're totally benign. Now, you can get cysts in, say, the pancreas and people start freaking out, all right? Again, most of them are benign too, but they have a precancerous risk and no one wants to get pancreas cancer. And so we worry about pancreas cysts a little bit more than we do about cysts, say, in the liver. So it just depends on what organ you're in and what you're dealing with. That's what med school's for. Go ahead. I was just wondering how the process of storage of bile changes when there's no gallbladder. Where does the- Good question. Good question. That's why people- I'm gonna use this pointer. Anything else? Top one, Steven. Yeah, I'm getting too old for this. I can't even figure out the technology. All right. This mouse has got a green dot on it, too. It's perfect. All right, so normally, you eat. The bile goes down here. I think it's pretty cool because normally, most tubes, you just kind of go in one direction, right? Because this ampulla is, say, closed, all right? I think of the ampulla, this may sound gross, but think of this like the anal sphincter, okay? It stays closed. Like right now, all your anal sphincters are closed. You're not in the bathroom having a bowel movement, all right? So this is closed. So bile comes down. It can't go through this. It goes up and goes into the gallbladder and sits there, okay? And then it gets concentrated. And then when you eat, the gallbladder squeezes and bile comes down this way. And this actually opens and relaxes, all right? So the same hormone that squeezes the gallbladder causes the ampulla to relax. And so this works in perfect harmony and bile comes down and into the small intestine. So if you don't have a gallbladder and you cut it off right here at the cystic duct, all right, your bile comes down and just gets stored here. And so patients with gallbladder surgery often have what they call a more dilated bile duct, right? So the bile gets backed up behind this ampulla. And so this bile duct can look more dilated in patients who've had gallbladder surgery, okay? That makes sense physiologically, right? You can't store it in here, so you gotta store it in here, okay? The other thing you find is that some patients who have gallbladder surgery for the first few months after the surgery, they can have excessive diarrhea, okay? And the diarrhea is because the bile can come down, overwhelm this, leak out. And basically, you get too much bile into your small intestine, get into your colon, it can irritate the colon and cause diarrhea. And so over time, your body will adapt, typically, or it can get treated with medications for a period of time. It will adapt to that, absorb more bile so it's not a problem, so people don't have lifelong diarrhea after gallbladder surgery. But it does change a little bit of the way things work. But fortunately, again, it's not an essential organ because it doesn't do anything that can't be managed another way, right? Your body adapts to that, all right, any questions? Okay, Keith, do you have a question? Okay, got it, that's each their own, all right. And so I think every jet actor has their favorite organ, right? So Dr. Calloway loved, I think it was small intestine or small bowel, right? Small bowel is not my thing, I love the pancreas. It's like, which flavor ice cream do you like? You get a bunch of jet actors in a room, they'll talk about their favorite organ. And so mine happens to be the pancreas. So this is the pancreas. It's a glandular organ, it's about eight inches long. I think it's very unique. So it looks like a tadpole, all right, it's got a head, neck, body, tail. And it goes from basically the right side of your belly, all the way across to the left side. It's closer to your back than it is to your front, right? So if you kind of look from the inside, if you would cut yourself open, you have the skin, the muscle layer, you have a bit of fat, your stomach, your pancreas is behind that, and then your spine, okay? So it's closer to your back, this is why when patients get, say, pancreatitis or inflammation of the pancreas, they talk about pain in the back, or they feel like they're getting stabbed with a sword that goes from the front all the way to the back and out, okay? Because it's closer to your back than the front. It's drained by this main pancreatic duct here, right? So all these little tiny streams that join to this main river, most of it drains down here through the main pancreatic duct, which meets the ampulla into your small intestine. There is a smaller duct here, the minor pancreatic duct, which drains a smaller portion of your pancreas through a separate opening in your small intestine. So this little guy has a couple of different functions. So unlike most of the GI tract, which has one main function, which is the GI tract function, right, digestion, absorption, nutrients. The pancreas has two functions, all right? So one is the exocrine function or the GI function. So it produces and secretes enzymes that break down fats, carbohydrates, and proteins. So if you don't have a pancreas, or patients with, say, pancreas cancer or pancreas surgery, they will lose a lot of weight because they can't absorb a lot of their nutrients. They don't have enzymes to break down the food that they're eating. So they're eating, you can't absorb it. It comes out as essentially this form of diarrhea or very oily diarrhea, okay? Because you need the pancreas enzymes to break down the food you're eating. It also produces bicarbonate, all right? You guys remember from chemistry class, bicarbonate neutralizes acid. So the stomach produces hydrochloric acid, which is a very, very strong acid, all right? It's a pH of two. Remember from chemistry, it's one to 14, seven is neutral. Two is a really, really strong acid, all right? So bicarbonate will neutralize that so you don't get all this acid throughout your small intestine and colon, okay? So it does an important role in that. This is just a process by which the small intestine gets food. It secretes this hormone called secretin, which then regulates bicarbonate production, which then neutralizes the stomach, right? So you see a lot of these cycles in the GI tract that are driven by hormones. That's how things work to kind of turn things on and shut things off, all right? The other function of the pancreas is the endocrine function, all right? My wife is an endocrinologist. This is the one place where we cross, all right, is the pancreas, all right? So endocrine means hormones, right? So my wife, for example, as an endocrinologist, she deals with diabetes, thyroid, pituitary gland. These are glands that make hormones, and you regulate the hormones in these diseases. And so the pancreas makes insulin, glucagon, and somatostatin that work on other parts of the body. And obviously, it's very much involved in sugar, glucose regulation of your body, and that's where the pancreas makes these hormones. So if you lose a large portion of your pancreas, you can't produce these hormones either, and you should become diabetic, for example, if you lose a lot of your pancreas, right? So basically, a pancreas surgery, they lose 80%, 90% of their pancreas, they become diabetic, right? Because you don't have enough cells anymore to make the insulin, the glucagon to regulate your blood sugar. Okay, I think that's it. All right, any question about the pancreas or the liver and gallbladder while you're at it? Dr. Opstein. I got one. Back to Tim, we were talking about sizes and stuff with different organs, and you mentioned a couple of times that the bile duct can become bigger. Any reference on how big a normal common bile duct is, and for that matter, what about the pancreatic duct? Just, because on here, it looks like it's 25 feet long. Yeah. Yeah. So this becomes relevant when you're looking at reports of imaging, right? And you wanna know if there's potentially some sort of blockage in your bile duct or your pancreatic duct, right? So your bile duct here, let's see if I can find it. Your bile duct, for most of us who are normal, healthy patients or people, it's about three to five millimeters, okay? So it's pretty small. As you get older, this becomes more dilated. So they say one millimeter per decade of life after 50. The easy way to remember it is, if you're under 50, three to five millimeters. If you're 60, six millimeters. 70, seven millimeters. Eight, eight millimeters. That's normal, okay? So if you see a 30-year-old with a 10-millimeter bile duct, you start to get worried about what might be going on, right? You worry about some sort of blockage here causing the bile duct to become more dilated up here, okay? So three to five millimeters is normal for the bile duct. The pancreatic duct is usually very, very small and wispy. This guy here looks very prominent anywhere between one to three millimeters, right? So very, very small. But again, if it's dilated, say you have a pancreas cancer or a stricture or narrowing here in the pancreatic duct, this will become dilated upstream, all right? A lot of the GI tract is plumbing, right? The GI tract is one long tube. The bile duct is a tube. The pancreatic duct is a tube. A lot of the stuff that, say, I do as an interventional endoscopist is to drain the plumbing, right? So if there's a blockage, we put a stent in it. We can dilate things to dilate strictures to help the flow of the GI tract. Yep. I have a question. It's a little off topic, but could you explain like a liver shot in boxing in MMA and why is it so debilitating to someone who gets it? Like a body shot or a liver? Liver, yeah. When someone gets punched in the liver, they basically can get knocked out. I don't know what a liver shot is, but I don't follow this MMA thing enough. I suspect if it's some sort of bruise, right, to the... The upper right quadrant. Yeah, so you can get, I mean, it's like trauma anywhere is usually not good, right? Actually, you know, with the most common injury to the abdomen, well, that's not really traumatic, right? I think about the spleen tends to cause a lot of bleeding, right? Spleen is not part of the GI tract. It's in the left upper quadrant. It's part of your abdomen. So you're like, oh, the spleen must be part of the GI tract. It's actually sitting over here to the left, like all the way out here, not on the screen, right? So way over here on the left, you hear about people getting tackled or say in a car accident and they get lacerations of the spleen, they bleed out and they go to the operating room, they gotta take the spleen out because it's bleeding. The liver doesn't tend to happen that much. So I don't know in MMA if they're going after the liver or something, but you know, if it's in the right upper quadrant, you could potentially cause a bruise or contusion to the liver, I suppose. That's what they're talking about, but I don't know enough about liver shots to speak intelligently about it. Go ahead. With regards to like alcohol consumption and you see cirrhosis of the liver. Yeah. Are all alcoholic beverages the same or are there others? Are you asking for your friend or your family? Is this for tonight? Is that why you want to know? Is it if there's one that's cleaner than others or? It's a good question. I'm sure if you look on the internet, you can find whatever you want to find about how much you can drink. No, so basically a shot versus a glass of wine versus a beer are thought to be equivalent, right? In terms of not just alcohol content, but in terms of the amount of consumption. So if you're having a 12 pack of beer, it's like 12 shots in terms of damage to your liver. I mean, the liver itself is pretty amazing. Like a lot of your body actually and that it can heal and repair itself, all right? It's just over repeated injury that your body gets to a point where it can't recover. Right? And I think everyone's different. And certainly for people who develop cirrhosis, which is kind of the end stage liver fibrosis that can happen after a number of diseases, including alcohol liver disease. Some of the studies will say you need to drink for, you know, men need to drink for 30 or 40 years at a very heavy amount or women drink for 20 or 30 years at a very heavy amount. But everyone's a little bit different. So certainly we see people who get alcohol liver disease who don't drink nearly as much as some other people. Now the people who drink a ton and get away with it without developing cirrhosis, right? Hopefully you fall into that category, but I wouldn't test it, right? I mean, I think the important thing is moderation. Thanks so much. Yeah. Can I just add to that? Sure. Walt just asked what is moderation? I know that's really what all you want to know. There is no threshold. Like if you drink above it, it's bad. If you drink below it, it's okay because it's multifactorial. Women are more predisposed to alcoholic liver disease than men. So the recommendation, I don't even know if it's called safe drinking, but where you start to worry about it is more than seven drinks a week for a woman and more than 14 drinks a week for a man. She's ready to get served. I'm good. What about in one day? But everyone's different, so don't test that, okay? I'm a lightweight. I have like two beers and I'm like out, so. All right. Any other questions before I finish? All right, thank you guys.

liver

gallbladder

pancreas

gastrointestinal tract

bile production

blood sugar regulation