 If we want to get blood to our abdomen, what's our route? We have to go through the aortic arch and into the descending thoracic aorta. And I am going to show a very thick, like all my vessels so far I haven't made them thick. And part of the reason why is it just, like we don't need them thick. The descending aorta in both thoracic and abdominal flavors is because there's lots of big branches and I'm drawing the whole thing. I'm drawing it thick so that you can see this. Before, we know that this is the descending thoracic aorta. I'm drawing a giant green anatomically incorrect diaphragm because maybe that is correct, like it actually sits, does the heart actually sit that closely on the diaphragm? Remember, it's not important. The important thing is that the thoracic aorta, as soon as it passes through the diaphragm, it becomes the descending abdominal aorta. The descending abdominal aorta, as soon as it enters into the abdominal cavity, as soon as it becomes the descending abdominal aorta, we have multiple branches that happen, that come branching right off. I am simplifying because you're glad that I'm simplifying. The first branch, it's a single vessel, so I'm drawing it as a single guy coming off. And it actually has three big branches, but for our purposes, we're only going to name one of the branches and we're going to send that branch to the liver. And I'm making everything, in fact, I must make it purple to indicate that we've got some capillary action going on here. Okay, so let's see here. Here comes this vessel. We need to name all these guys. The first, the branch, the vessel that actually comes off of the abdominal aorta, this is my celiac trunk. And the branch of the celiac trunk that feeds the liver is called the hepatic artery. That works. So the celiac trunk branches off and becomes the hepatic artery. It also branches into a bunch of other vessels, but we're just going to go awesome. There's a bunch of named vessels that feed the following structures, the stomach, the spleen, and the pancreas. Okay, we're feeding gut structures. Bringing gut structures, fresh, delicious blood and ending up with a capillary bed in there so that we can do the gas exchange and think about this nutrient exchange. Stomach, stomach doesn't do a whole lot of absorption of materials during the digestive process, but it does some, it absorbs some things. And those things, the absorption happens in the capillary beds. That's branch number one. Branch number two, we can go back to our red color. Branch number two happens just inferior to the celiac trunk and this guy is called the superior mesenteric artery. And once again, the superior mesenteric artery is going to have lots of branches. But I'm going to draw it. I'm sort of not having very much room here, but I'm going to draw it like this and I'm going to tell you that it feeds mostly the small intestines. So far so good, like this totally works for me. We keep on descending with our descending abdominal aorta and just beneath the superior mesenteric artery we get a sort of giant branch. And I'm only going to, I'm going to draw it on both sides even though I'm not going to extend it on one of the sides. But it's on both sides because guess who this guy feeds. I'll tell you who it is first. Who is the renal artery? Who is that renal artery you speak of? Who does it feed? Yeah, it feeds your kidneys. So the renal arteries feed the kidneys. Now they're huge. They really are that, like they're crazy huge. Why? Because you are doing a lot of blood filtering using those giant renal arteries in your fantastic kidneys which are the topic of our next little section of anatomy. All right, now watch this. My descending abdominal aorta ultimately at like level L3. So imagine this guy going down until it reaches about L3. At about that level, this guy branches into two different arteries. What now looks like a little man, a little cyclops? What do you think these giant branches are going to do? Pat your legs because they are feeding your legs and we'll talk about those guys when we get into the lower limb. We're not finished. Are there any gut structures that you feel like, dude, we can't leave this guy out? Well, I'm definitely thinking, dude, we can't leave this guy out. We have an inferior mesenteric artery, nice, and the inferior mesenteric artery is feeding the large intestine, mostly, not the LT, VLI. I think that's everything that I need to tell you at this point. All of this is feeding fresh blood to gut structures. Now we have to talk about a specific system that we go through in order to bring the blood back. So once the blood, I mean, we all know, like red arterial, purple capillaries and gas exchange, blue venous, and let's go back to the heart. Ultimately, where do you think we're going to drain? What vessel is our ultimate destination? Inferior vena cava. Eventually we want to get there. This is interesting and kind of fun, and like one of my favorite things. Everything's my favorite thing. One of my favorite things, route to get there, and it involves the hepatic portal system. So let's go check that out.