Duct System of the Liver, Gallbladder, and Pancreas - Online Tutor, Practice Problems & Exam Prep

The liver, gallbladder, and pancreas connect to the small intestine via several ducts. The common hepatic duct carries bile from the liver, while the cystic duct leads to and from the gallbladder. Bile travels down the bile duct to the duodenum. The pancreatic duct transports pancreatic juice, entering the hepatopancreatic ampulla before passing through the hepatopancreatic sphincter into the duodenum at the major duodenal papilla. This coordinated system is essential for digestion, allowing the release of bile and enzymes necessary for nutrient absorption.

Duct System

We now want to spend some time looking at the different ducts that connect the liver, the gallbladder, and the pancreas to the small intestine. So we're just going to start by saying to reach the small intestine, bile and pancreatic juice travel through several ducts. And we're going to look at them all now, but first, let's just orient ourselves to our image here. You can see the liver, that large reddish-brown organ on the top. You see the gallbladder, that sort of pear-shaped green organ sort of tucked under the liver. You see the pancreas, that sort of long yellow organ, and we see the small intestine, the duodenum, that first section of the small intestine right there up next to the pancreas. Now importantly, you also see sort of in green and brown running through the middle here, these ducts, and that's what we want to talk about.

Alright. The first one we want to identify here is the common hepatic duct. And the common hepatic duct, well, hepatic refers to the liver. So this is the duct leaving the liver. And you can see we're going to highlight that in light blue right there. So this is going to carry bile down out of the liver, and that common hepatic duct, it's actually pretty short. It just goes until it reaches the joining point of the cystic duct. And the cystic duct, well, remember, cystic, we said that refers to a bladder, and here we're referring to the gallbladder. This is the duct leading to the gallbladder. We'll highlight here in that sort of darker blue color there. Remember, there's just one duct. So this is the same duct in as out. Bile goes into the gallbladder this way, and then when it's squeezed out, it goes back down that same cystic duct.

And then any bile headed towards the small intestine, whether it's from the liver or from the gallbladder, is next going to travel down the bile duct. And the bile duct, this is leading away from the cystic and hepatic ducts, and we're going to highlight it here in purple. This is how all that bile makes its way down to the small intestine. Alright. Well, that's how the bile travels down. Well, we're also talking about here that pancreatic juice. For the pancreatic juice, well, we had one major duct that we talked about, that pancreatic duct. This was that central or main duct of the pancreas, and we're going to highlight it here in that orange color in the center there. Now remember, we also had that accessory pancreatic duct, and you can see that in the image, but you're less likely to be responsible for that because not everybody has one.

Alright. So that's how the bile and the pancreatic juice get down towards the small intestine, but we haven't talked about how they actually get in yet. So let's look at that in some detail. We're going to zoom in here, and we want to talk about these structures where these ducts meet and enter into the small intestine. So the first thing we want to identify is the hepatopancreatic ampulla. Well, hepatopancreatic hepato that refers to the liver and pancreatic that refers to the pancreas and an ampulla. Well, an ampulla is a name for a jug or a flask from ancient times. It's sort of, big and round on the bottom and narrow on the top. So that is the meeting point of the bile and the pancreatic ducts, and we're going to highlight it sort of in that bright red color here. So you can imagine this ampulla, this sort of flask turned on its side with a big wide round parts kind of up against the small intestine, and it sort of gets narrower, where those, where those ducts, the bile duct, and the pancreatic duct meet and enter into that ampulla.

Okay. So those pancreatic juice and the bile enters into the hepatopancreatic ampulla, but it can't get into the small intestine until it goes through the hepatopancreatic sphincter. Remember, a sphincter is just one of those muscles that's like a circle, and it squeezes down to not let anything through. So this controls the release of bile and pancreatic juices into, I'm going to say here, the duodenum. And remember the duodenum, that's just that first section of the small intestine. Now you can't really see the sphincter in this drawing, but it would be right around here, right around that opening, so it can squeeze down and control whether stuff goes through.

Alright. But one thing that you will note that when you're looking at that opening, for how these juices are actually getting into the small intestine, if you're looking at it from inside the small intestine, it almost makes this, like, donut shape there that I'll highlight here. That donut shape has its own name. That's the major duodenal papilla. So the major duodenal papilla, that is the entry point for bile and pancreatic juice into the duodenum. Alright. Now why is the major duodenal papilla? Well, remember, some people have that accessory pancreatic duct. So if you have an accessory pancreatic duct, you'll also have a minor duodenal papilla where that smaller duct also goes into the duodenum there. But this one, everybody has, and it's nice and big because it's where both the bile and the pancreatic juices come in, the major the major duodenal papilla.

Okay. So as we look here, those are our ducts. That's how this stuff gets into the small intestine. We're going to practice following these pancreatic juices and this bile through this duct system. Coming up. I'll see you there.

Duct System of the Liver, Gallbladder, and Pancreas Example 1

Our example tells us that listed below are three chemicals that end up in the duodenum and where those chemicals originate. Now, using the word bank below, fill in the pathway that the chemicals had to pass through to reach the duodenum. Some terms will be found in more than one pathway. Alright. So, the things we're talking about here are bile from the liver, bile from the gallbladder, and pancreatic juice. And then we have this word bank here that those are the things it's going to pass through to get there. So, let's just start with bile from the liver.

Well, bile from the liver obviously starts in the liver. What does it pass through next? Well, this word bank, the first thing I see is that common hepatic duct. Remember, hepatic refers to the liver. So first up, I'm going to put 'c' here for the common hepatic duct. Where does the bile go next? Well, the common hepatic duct connects to the bile duct. So 'b' comes next. Now that bile is flowing down the bile duct, where to next? Well, next is going to come here, 'e,' the hepatopancreatic ampulla. Remember, that's where that bile duct and the pancreatic duct meet. So 'e' comes next, but before we can actually make it into the duodenum, we've got one more thing we have to go through. What's that going to be? Well, from this list, it's the major duodenal papilla. Remember, that's that sort of donut shape that you can see on the inside of the small intestine. So I'm going to put 'd' here, the major duodenal papilla, and now that bile has made it to the duodenum.

Well, what about bile from the gallbladder? Well, it's going to start in the gallbladder. Where does it go next? Well, from there it goes down the cystic duct. Remember, cystic refers to a bladder. In this case, the gallbladder. So I'm going to put 'c' on the line first. Remember, that's how that bile gets into the gallbladder and back out again. Well, from the cystic duct, where does it go? Well, bile will go down the cystic duct and into the bile duct, 'b' there. Well, now we're in the bile duct and that's where we were with bile from the liver. So the rest of it's going to be the same. It's going to go through the hepatopancreatic ampulla, 'e,' and then through the major duodenal papilla, 'd,' and into the duodenum.

But what about pancreatic juice? Well, that starts in the pancreas, and what does it go through next? Well, that major duct running through the middle of the pancreas, that was the pancreatic duct. So I'm going to put 'a' next. Alright. For the pancreatic duct, where does it go? Well, the pancreatic duct sort of meets up with that bile duct at the hepatopancreatic ampulla, so that's coming next. And all these things, once they go through into the hepatopancreatic ampulla, the next thing they're going to go through is the major duodenal papilla. Right there, 'd,' so I'm putting that on the line, and now that pancreatic juice is in the duodenum.

Alright. With that, we did it. We have practice after this. Give it a try.

Bile and pancreatic juice will first come in contact in the:

• A. Hepatopancreatic ampulla.
• B. Duodenal papilla.
• C. Pancreatic duct.
• D. Bile duct.

Gallstones are hard “stones” made of cholesterol or bilirubin that can form in your gallbladder or bile ducts. A patient has a gallstone located in one of the ducts associated with the gallbladder. If the bile is able to reach the gallbladder but not able to reach the duodenum, in which duct is the stone likely located?

• A. Common hepatic duct.
• B. Bile duct.
• C. Cystic duct.
• D. Pancreatic duct.

Here’s what students ask on this topic:

What is the function of the common hepatic duct in the liver's duct system?

The common hepatic duct plays a crucial role in the liver's duct system by transporting bile produced by the liver to the small intestine. Specifically, it carries bile from the liver to the point where it joins the cystic duct, which leads to the gallbladder. From there, bile can either be stored in the gallbladder or continue its journey down the bile duct to the duodenum, the first section of the small intestine. This process is essential for digestion, as bile aids in the emulsification and breakdown of fats.

How does bile travel from the gallbladder to the small intestine?

Bile travels from the gallbladder to the small intestine through a series of ducts. Initially, bile stored in the gallbladder is released into the cystic duct. From the cystic duct, it moves into the bile duct, which is a common pathway for bile from both the liver and the gallbladder. The bile duct then carries the bile to the hepatopancreatic ampulla, where it mixes with pancreatic juice. Finally, the bile passes through the hepatopancreatic sphincter and enters the duodenum at the major duodenal papilla, aiding in the digestion of fats.

What is the role of the hepatopancreatic ampulla in the digestive system?

The hepatopancreatic ampulla, also known as the ampulla of Vater, is a critical structure in the digestive system where the bile duct and pancreatic duct converge. Its primary role is to serve as a mixing chamber for bile and pancreatic juice before they enter the small intestine. The ampulla ensures that these digestive fluids are properly combined and regulated. The release of these fluids into the duodenum is controlled by the hepatopancreatic sphincter, which helps in the efficient digestion and absorption of nutrients.

What is the significance of the major duodenal papilla in digestion?

The major duodenal papilla is a vital structure in the digestive system, serving as the entry point for bile and pancreatic juice into the duodenum, the first part of the small intestine. This papilla ensures that these digestive fluids are released in a controlled manner, regulated by the hepatopancreatic sphincter. The bile aids in the emulsification of fats, while the pancreatic juice contains enzymes that further break down carbohydrates, proteins, and fats. This coordinated release is essential for efficient digestion and nutrient absorption.

How does the pancreatic duct contribute to the digestive process?

The pancreatic duct is essential for transporting pancreatic juice from the pancreas to the small intestine. This juice contains digestive enzymes that play a crucial role in breaking down carbohydrates, proteins, and fats. The pancreatic duct merges with the bile duct at the hepatopancreatic ampulla, where the pancreatic juice mixes with bile. This mixture then passes through the hepatopancreatic sphincter and enters the duodenum at the major duodenal papilla. The enzymes in the pancreatic juice facilitate the chemical digestion of nutrients, making them easier to absorb.