Yeah, let's shake it off. So I'm gonna talk a little bit about basic anatomy of the liver, gallbladder, pancreas. The answer to the question is the same thing, but we'll go into it a little bit more. Here's the GI tract when we're looking at the liver, gallbladder, pancreas. If I had a pointer, I'd show you that the liver, mostly right upper quadrant, goes off into the left with the gallbladder underneath. Pancreas sits in the middle, a little bit off to the right towards the left between the kidney and the spleen. You have the esophagus, which we talked about, stomach, and the large and small intestine. So we're gonna spend the next 15 minutes talking about the greater than 500 vital functions of the liver, and then there's gonna be a quiz at the end. No, I'm kidding. But it lives in the right upper quadrant, weighs about four pounds. It's the largest solid organ in the body. Who can tell me what's the other largest, actually probably the largest organ in the body? Skin. Skin, yeah, easy. Two distinct sources of supply, blood supply, that's the hepatic artery and the portal vein. All right. So the liver's broken up into four different lobes. When you look at it from up front, you only see the right lobe and the left lobe, and then you have the caudate lobe and the quadrate lobe. And then it's split up into the, as I mentioned earlier, the hepatic vein and the portal vein. Hepatic vein bringing oxygenated blood into the, and where's the hepatic artery in this one? Oh, there's the hepatic artery, sorry. Right here. Hepatic artery bringing in the oxygenated blood to the liver and the portal vein, bringing the oxygenated blood into the liver. When we look at the biliary anatomy, and this is what, as an advanced endoscopist, I spend a good portion of my time looking at, we have the bile ducts that are separated into different areas that are represented by the different segments of the liver. And that's broken up into the lobes, and it's also broken up into different segments that mimic the vasculature. But here you're seeing the ampulla or the major papilla. There's also a minor papilla, which is part of the pancreas, where the pancreas drains. So the bile duct drains through the liver. A portion of it lives inside the pancreas and drains into the small intestine. And at the same opening, within the same opening, you have the pancreatic duct draining. So both the bile duct and the pancreatic duct drain through the same major papilla ampulla of water. You have the gallbladder sitting underneath the liver. You have the cystic duct, which communicates with the common bile duct. And a piece of anatomy for you to understand, the common bile duct is the portion of the bile duct that goes from the ampulla or the major papilla up to the cystic duct. Anything above the cystic duct in the extrahepatic, outside of the liver, bile duct is called the common hepatic duct. So that goes from here to here. And then you have this confluence of ducts. So we talk about confluences and bifurcations. Confluence is where two ducts come together. Oftentimes this will be called a bifurcation as well, where you have the left hepatic duct going towards the left lobe of the liver, and then the right hepatic duct, which is broken up into different segments. When we're doing procedures, so let's say you walk into a room and somebody's doing an ERCP, you're looking at an image and what's seen on the screen is as if that patient's facing you. So when you're seeing a fluoroscopic image, the right side of the screen is the left side of the patient and vice versa. So it's kind of flipped, but your brain, as we're doing these procedures, understands it that way. So in this same way, so what you're seeing over here is the right side of the liver and this is the left side of the liver. So what's the function of bile? Bile is produced by the liver. It's a greenish yellowish fluid. It's stored in the gallbladder and it's released in response to a fatty meal. So the body produces cholecystokinin, causes the gallbladder to squeeze, bile comes out through the cystic duct and drains into the small intestine. And what does it do there? It aids in the absorption of fats and fat-soluble vitamins, A, D, E, and K. So that's why in some patients who have disorders of the liver and they're not producing appropriate amounts of bile, will also have deficiencies in fat-soluble vitamins, A, D, E, and K. Other functions of the liver, so we're down to 450 left, synthesized clotting factors. So it helps in, so patients who have cirrhosis, we'll get into that a little bit later, have deficiencies, are both prothrombotic and anticoagulant to a certain extent. So they're not producing the clotting factors that help, but also they have a propensity to bleed. They kind of balance themselves out to a certain extent and there are different factors that we look at to measure that. Also synthesize glucose, proteins, and cholesterol. The liver stores, a big portion of what it does, it stores glucose in the form of glycogen. It stores vitamins such as A, D, B12, and K, and also minerals such as iron and copper. Helps break down, it's a filter. It's really like a big filter for medications, drugs, alcohol, and toxins. So with many of the medications that are available out there you have to look at first pass metabolism, and you have to look at the way the liver metabolizes it in order to understand how much of it is available to exert an effect on the patient. Same applies to kidneys, same applies to other, so when a medication is given, there's some that are 100% bioavailable, there's 70% bioavailable. That depends on how much of it, if it's being broken down by the liver, how much of that is being metabolized by the liver. So moving on from the liver, we're looking at the pancreas. So as I mentioned earlier, it's a glandular organ, it's about eight inches long. It goes from the right, midline to the right upper quadrant, and then it kind of courses upwards towards the left. And it lives between the spleen and the left kidney. It has several functions. It's, when we talk about drainage, so when we talked about the bile duct in the liver, we talked about drainage coming from the liver down into the small intestine. When we talk about the secretions coming from the pancreas, it secretes, this is the tail of the pancreas, but the secretions come this way. So it's kind of confusing, even if you took a survey of 100 physicians, they'd all probably disagree as far as the way things are. The duct is considered to be, some would say this is a distal pancreatectomy when they're resecting the organ of the pancreas, they're getting rid of the distal part of the pancreas, but oftentimes we're talking about the proximal duct draining into this area right here, which is the small intestine. Don't wanna confuse you, but just understand that when we talk about terminology of the pancreas, sometimes it's easier just to say where we're, what part we're looking at, the tail, the body, the neck, the head, and the hook is the untenate. There is no foot. I think that was one of the questions. In case anybody got that one wrong. So what are some of the functions of the pancreas? The pancreas produces, so it has broken up into two big areas, the exocrine and those endocrine, so the ones that are non-GI that are through the bloodstream. Exocrine are enzymes that are produced and secreted through the pancreas, through the pancreatic duct in order to break down fats, carbohydrates, and proteins. So you produce another one called secretin, which is, produces by, secretin is stimulated to produce bicarbonates and neutralize stomach acid. I will get into that in a second just to show what that negative feedback loop looks like. Some of the endocrine functions of the pancreas to produce hormones that act on other parts of the body. So they don't act locally in the area of the pancreas. They act, they send their hormones throughout the bloodstream to other parts of the body, and that's to produce insulin, glucagon, and somatostatin. So when we're talking about patients who are diabetic, they have dysfunction in the islet cells of Langerhans, which live within the pancreas, or at least that's one type of diabetes. All right, so talking about this negative feedback loop, acid from the stomach enters the small intestine, the first part, the duodenum, some call it the duodenum, and that stimulates the release of secretin into the bloodstream. And what does that do? That actually causes the pancreas, the secretin stimulates the pancreas to produce bicarbonate, bicarbonate which is secreted through the pancreas into the small intestine in order to neutralize that acid. So somebody who has an ulcer in the small intestine is gonna be different than somebody who has an ulcer in the stomach, partially because of that bicarbonate that's being produced into the small intestine. And oftentimes what we'll see as an advanced endoscopist, you'll see somebody who has a blockage in the pancreatic duct, you'll see a little ulcers there because they're not producing that bicarbonate. So all of a sudden that acid that's coming out of the stomach is now unopposed. And that acid, the small intestine is testing in the same way that the esophagus doesn't respond well to acid, is causing a local effect on the esophagus or on the small intestine. And bicarbonate neutralizes acid in the small intestine, in the duodenum or duodenum. Okay, so what does the GI tract and health look like? We know that the pancreas breaks down and absorbs, it serves to break down, for the breakdown and absorption of food and nutrients, absorption of water and minerals, movement of contents via coordinated motility and storage of waste through the waste, through the colon as discussed earlier until elimination. I know I ran through a lot of that really quickly, but I'll take some time for questions because there's a lot of material here that we can discuss. So somebody asked about the major papilla, ampulla. One of the things to understand also is when we look at the pancreas, the pancreas has the main pancreatic duct. There's also the minor papilla, which is the duct of, where the duct of Santorini exits the pancreas. And I could show you where that is. So about 10% of people, as an embryo, the pancreas is made up of two buds. There's the ventral and the dorsal bud, and those two buds wrap around. One is on this side, and they wrap around, and they fuse early on. I think it's six weeks of gestation, so as a little embryo. Once those fuse, they form the main pancreatic duct, which has two areas, the duct of Wurzong, the duct of Santorini. The reason that I'm bringing this up is about 10% of people don't have this connection, so those two ducts don't fuse. And oftentimes, what ends up happening is the main pancreatic duct, which is through here, will now drain directly through the minor papilla. So the major is here, the minor is here. And the reason that this is relevant, sometimes people can have recurrent pancreatitis or pain, or it's at least postulated that they may have those symptoms related to that. Questions? I have a question. This is a liver question. Sure. Okay, so I hope I asked this the right way. So with the increase of fatty liver disease, and patients go in and they see their non-GI doctor, just a primary care physician, but with all these new tools out, like fatty liver quantification and so on, is there guidelines when that primary care physician should be referring them to a GI hepatologist? Great question. Oftentimes, it's related to any sort of dysfunction in that balance, if I understand your question correctly. So if the patient is having some sort of abnormality, if they're even seeing a slight increase in their AST or ALT in their liver enzymes, or if they notice that there's some issue with their liver function, that would be the appropriate time to send them to a hepatologist. And as we had discussed earlier, GI is becoming much more subspecialized. Two big branches are just early on, you have gastroenterologists and hepatologists, hepatologists dealing with mostly those problems of the liver. So if there is a concern that there is some dysfunction, and especially in those patients who have metabolic-associated dysfunctions, to refer them early, just so at least they can have that follow-up. So if, let's say, the normal ALT is 19 or 20, if it's much more than that, that would be an appropriate time to refer out. Does that answer your question? Other questions? Yes? Or pancreatic disease, like there are colonoscopies scheduled at 40 years of age, is there any kind of benchmark where people need to get tested for any certain thing? For high-risk individuals. So let's say somebody has an underlying liver problem, somebody has cirrhosis, or somebody has hepatitis B from early on, or a vertical transmission, they have it at birth, those are patients that you would have certain screening for them. Or let's talk about somebody who has a familial pancreatic cancer. We know that dad and grandma and uncle have pancreatic cancer. Those are where we're starting to develop guidelines to have appropriate screening. Otherwise, there is no real routine screening, and hep C as well, with the hepatitis. So with these patients, we would have some sort of screening, but otherwise, there isn't, just for the general population in the absence of disease, we don't have some established screening for these. No, I would say, too, if you're going to your primary care, to the question before, you're probably at some point gonna get a C and P or a B. If we're seeing liver abnormalities that make us wonder about metabolic diseases, like you have a metabolic disease and they make us wonder about NASH, that may be it, but it's more like a part of just general screening to get your liver checked at some point in your life. And not as organized or purposeful like colorectal cancer screening. So we wouldn't do genetic screening unless there was a reason for it. So there were some familial traits that prompted us, or the patient came in with a cancer that may be of a familial type, then we would do some genetic screening. Or there are some liver disorders that also warrant genetic evaluation, but not necessarily screening per se.

anatomy

liver

gallbladder

pancreas

digestion