Our example here says that for each of the structures or functions below, identify whether they are most closely associated with the duodenum, the jejunum, or the ileum by writing the correct letter on the line. Some structures or functions may be associated with more than one region of the small intestine. Alright. So we have the duodenum, jejunum, and ileum over here. That's where we've got to put our answers, and we have a through j here. So let's start going through it.
Alright. Pyloric sphincter. Which part of the small intestine do you think that is most closely related to? Well, pyloric sphincter is how you get into the duodenum. So I'm gonna put an a here. Pyloric sphincter is between the stomach and the duodenum.
What about b? Contains a brush border. What do you think about that? Well, we talked a lot about the brush border in relation to the jejunum, but the brush border is just the microvilli of the small intestine and that's gonna be everywhere. So the brush border, that's gonna be through the entire small intestine. I'm gonna put b on every one of these lines here.
What about the major duodenal papilla? Where would you find that? Well, remember the major duodenal papilla, that's what the bile and the pancreatic juice enter through, that sort of donut shape that you can see on the inside of the small intestine there. And well, the major duodenal papilla, it's in the duodenum. All right. So I'm going to put c on that line for the duodenum.
Next, we have site of most nutrient absorption. What's that going to be? Well, most nutrient absorption happens in the jejunum. So I'm going to put a d on that line.
Next, we have the ileocecal valve. What is the ileocecal valve most associated with? Well, it's the ileocecal valve. It's the valve between the ileum and the cecum. So I'm going to put an e on the line for ileum there.
Next, we have contains chyme. Which one of these contains chyme? Chyme is going to be throughout. Right? Chyme is just that partially digested food in the small intestine. So chyme or f, I'm going to put on each one of these.
Next, we have g, the entry point for the bile duct. Alright. Where does the bile duct come in? Well, we already put it on here. That bile duct comes in at the major duodenal papilla, and that major duodenal papilla we said is in the duodenum. So I'm going to put a g up here on the line for the duodenum.
Next, we have region where bile salts are absorbed. Well, bile comes in in the duodenum, but those bile salts are reabsorbed in the ileum so that they can be recycled. Alright. So I'm going to put h on the line for ileum.
Brings me to i, specialized glands produce alkaline mucus. Alright. Where is that alkaline mucus going to be made? Remember the acidic chyme is entering from the stomach into the duodenum. So you have that alkaline mucus protecting the duodenum from that acidic chyme. So I am going to put an i on the line for duodenum.
One more. It says the longest region of the small intestine. So which of our three regions is the longest? That's the ileum. So I'm gonna put a j on the line there. Remember, the duodenum is really short, just like 10 centimeters. The jejunum, that's a couple of meters, and the ileum is even longer.
With that, we've identified all our parts. We've matched them all up. Good work.