Welcome to a new video on my channel, The Easy Anatomy, by Juan José Sánchez. This is Dr Juan José Sánchez, a surgeon who graduated from the Universidad de Oriente in Venezuela. And today I bring you a video about the anatomy of this beautiful organ, that is, the anatomy of the pancreas.
I will greatly emphasize the importance of this organ since it is an organ that is essential, it is vital for life. In addition to talking about the pancreas from an anatomical point of view, we will also talk about the pancreatic ducts, which are those that drain their large secretion product into what is basically the intestine. So we will begin by talking first about the generalities, then we will walk through the portions, the most important anatomical relationships, both peritoneal and non-peritoneal.
Finally, we will address its irrigation, venous drainage and innervation. Don't detach yourself from the video then. [Music] I invite you to subscribe here in the lower right corner, click.
[Music] And don't forget to like the video. So, it is very important that you subscribe here in the lower right corner, click on it so that you can help the channel grow and be able to access all of its content. So, the first thing you have to know about this pancreas is that it is an organ that is retroperitoneal.
What do I mean by retroperitoneal? Well, all this transparent membrane that you see here is nothing more than the parietal peritoneum. All the organs that are behind this parietal peritoneum are the retroperitoneal organs.
That is to say, then the pancreas, being a retroperitoneal organ, is only covered by parietal peritoneum on its anterior surface, while the posterior surface is free. That is, it is in direct contact with the muscles of the posterior wall of the abdomen and with the other structures found within the peritoneum. So, this is the most important thing you have to know at first, is that it is a retroperitoneal organ.
The second thing is that it is a gland, that is, it produces products that are secreted or excreted and that this gland is a mixed type gland, that is, it is both endocrine and exocrine. As an endocrine gland, it is its greatest importance because only 2% of this gland produces insulin, which is the most important hormone and is what gives it endocrine clearance. It produces many other important hormones besides insulin.
Now, the other 98% of the organ is responsible for producing pancreatic juices, very important for digestion. Then, these pancreatic juices are excreted into what is the duodenum, that is, the small intestine, through some ducts that I will explain to you later. That is why this organ, then, is both endocrine, due to the secretion of hormones, and exocrine, due to the production of pancreatic juices.
It is very important that you master the anatomy of the duodenum to be able to understand this video. It's on my channel, you can search for it. Likewise, I will leave it at the end of this video so that you can understand the anatomy well.
So basically, the pancreas has three large portions. The books even write a fourth portion. First we are going to have what is the large head of the pancreas.
Then we are going to have what is the body of the pancreas, which is the longest part of the pancreas. It is said that at the junction of the head and the body we find what is the neck of the pancreas. Remember, anatomically there always has to be a neck at the junction of the head and body , which would be like a narrowness.
And finally, the most distal portion of the pancreas, which would be the tail of the pancreas. So it is said to have a shape like a snake, since it has a head, a body and it has a tail. Now, in general terms, we are going to find at the level of the head of the pancreas this extension that you see here, which is an extension that is to the left and is an extension that is upwards, behind these vessels that They are the superior mesenteric vessels.
They call this extension an uncinate process, because it is shaped like an uncinate, that is, it has a hook shape. Now, at the union of this uncinate process and the rest of the head of the pancreas, we find this notch. See that it has a C shape, with the concavity to the left.
In that notch, which is called the pancreatic notch, we find the mesenteric vessels, but more specifically, we find the superior mesenteric vein. These are the structures, then, that are in relation to the head. Something important about the head is that the pancreatic ducts end in the head of the pancreas.
Even this duct that you see here, as I will explain later, is the common bile duct, which perforates the head of the pancreas. I also invite you to watch the bile duct video where I explain the anatomy of this common bile duct very well. Thus, this head of the pancreas is in direct relation to the concavity of the duodenum, because the secretion products of the pancreas end up in the second portion of the duodenum.
So, these are intimately attached. If you always see a corpse with you, you will see the head of the pancreas very attached to what is the concavity of the duodenum. Now, at the level of the body of the pancreas, in the upper most anterior part, we find an elevation.
This elevation is then called the pancreatic tubercle, it is just below what is the celiac trunk. And at the level of the tail, we find that this tail is in close relationship, even almost united to what is the vessel, through this ligament that you see here, which is the renal splenic ligament. We are going to see it very well in this image.
We see the pancreas, this is the most distal part, the tail. We see how this ligament is joining the pancreas, then, to what is the spleen. It is the splenic ligament, which is what the spleen means, and the renal ligament, because it is also the part that joins the kidney.
Renal splenic ligament joins the tail of the pancreas to the spleen. Now, what are going to be the most important anatomical relationships of this pancreas? Let's see that previously, we find the narrowest one with the posterior surface of the stomach, which here is raised by some hooks.
Then, the posterior face of the stomach is immediately related to the anterior face of the pancreas, between the two there is a space that is the famous great transcavity of the omentum. In fact, see that here they insert a wire that enters through the Winslow hiatus, which is the beginning of the omentum transcavity, and reaches directly to the omentum transcavity. In addition to that we are going to see that as a very important previous relationship there is the transverse colon and the part of what is the visceral peritoneum that supports the transverse colon, I am talking specifically about the transverse mesocolon, it is said that the root of the transverse mesocolon, that is , the origin of this fold of this peritoneum that cuts the peritoneum completely crosses the anterior part of the pancreas as we are going to see right now.
Here you can see very well the relationship that exists between the posterior surface of the stomach and the anterior surface of the pancreas and all this space that is here is the transcavity of the omentum or omental transcavity. See then here in this image to finish the previous relations, how the entire root of this transverse mesocolon passes through the pancreas from the head to the tail. It is a very important previous relationship.
As further relations, we will start from right to left. In the head, we are going to find from behind what the inferior vena cava is and what the abdominal aorta is. In addition, we find the common bile duct, which is first posterior to the head of the pancreas and then pierces the head of the pancreas.
So, this pancreas is closely related to this common bile duct. In addition to that, the right kidney is supposed to be here, so the right renal vessels, I mean the right renal artery and vein, are posterior relations of the head of the pancreas. And also, what are the gonadal artery and vein on the right side.
We see here, this would be the concavity of the duodenum, this would be the head of the pancreas. See the immense relationship that the head of the pancreas has with the common bile duct. And here is what I am telling you about what it has with the renal artery and the renal vein.
Let's now go to the relationships that exist at the neck level. At the level of the neck, there is said to be the superior mesenteric vein, as well as the portal vein. Reminding them that the The portal vein, in turn, is formed by the superior mesenteric vein, specifically it is the vein that forms the posterior relationship of the neck of the pancreas.
Now, at the level of the body of the pancreas, as the longest portion, the one that will have the most posterior anatomical relationships, in the posterior part, basically deeply, we find the diaphragm and we find the superior mesenteric artery. So, remember that the posterior vein of the neck, but the posterior relation artery of the body. Towards the part most looking for the tail of the pancreas, we find the relationship of the body with what is the left adrenal gland, as well as with what is the left kidney.
If we could dissect here, we would also see that the left renal vessels, I am talking about the renal artery and vein, are also posterior relations of the body. Now, at the level of what the tail is, we find what the splenic vein is and the splenic art. Note, the splenic artery and vein are relationships in both the tail and the body of the pancreas, but what is much more related to what the tail of the pancreas is.
And also what I told you just now, that the tail of the pancreas is very attached to what is the spleen. Here we see the union of the school of the pancreas again with the spleen and the splenic vein as it is the posterior relationship of the body and what is the tail of the pancreas. Now, in this image it says duodenal ducts, but I'm really going to explain exactly the ones from the pancreas that drain into the duodenum, except that I will also name the common bile duct, that is, the title of duodenal ducts is not so bad.
So, first I want to talk to you about the common bile duct, which is a duct that brings bile from the liver to empty into the second portion of the duodenum. A bile that is very important for digestion , specifically, of fats. Now, the pancreas has two ducts, one duct that runs completely through it from the tail to the head, it is the main pancreatic duct.
This main pancreatic duct is also called the Wirsung duct. This duct, when it reaches the level of the neck, makes a sudden or bend downward and then again to the right to join with the common bile duct. The union between the main pancreatic duct and the common bile duct is very important, that is, both secretion products drain equally into the same orifice in the duodenum, specifically in its second portion.
Now, there is another pancreatic duct that is said to be an accessory pancreatic duct, also called Santorini duct. It's accessory because some people have it and some people just don't have it. When it exists, it drains a large portion of the neck of the head of the pancreas and also drains into what is the duodenum.
Now, there is something very important, here we see the common bile duct and the main pancreatic duct schematized . The thing is that both ducts, when joined, create dilation. This dilation is called the ampulla of Vater or it is also called hepatopancreatic.
Because the hepatic duct comes, which is the common bile duct, and the main pancreatic duct. So, we see here the second portion of the duodenum, which has two openings. We can call these orifices papillae or caruncles, which are synonyms in anatomy.
The one that is most inferior, which is a little larger and thicker, is the greater duodenal caruncle, also called the greater duodenal papilla. The ones that are most superior are the minor duodenal papilla, also called the minor caruncle. These papilla are, listen carefully, the largest one where it secretes its product, the common bile duct along with the main pancreatic duct, while the smallest one is where it excretes the product, the accessory pancreatic duct or Santorini duct.
He secretes alone, without union, not like the main one does, which does join the common bile duct. Then, there is a series of sphincters that are specialized muscle fibers at the mouth of these ducts. This one that we see here at the level of the common bile duct, we are going to call it the common bile duct sphincter or the eponymous name that is the most famous in fact in anatomy, which is the sphincter of Oddi.
Then, we have this one that comes in orange, which would be the sphincter of the pancreatic duct. And this one that is already at the junction of both ducts, which is in blue, which is the sphincter of the ampulla of Vater, hepatopancreatic sphincter. We see it very well anatomically.
This would then be that of Oddi, this would be the pancreatic and this would be the sphincter of the ampulla of Vater itself. Now, almost to finish, let's quickly talk about irrigation of the pancreas. As it is an endocrine organ, any time you see a gland that produces hormones, it is something that has to be densely irrigated.
Now, let's see that the head of the pancreas has two large arches. One that is in front, which is the anterior duodenal pancreatic arch, and one that we see here that is a little transparent because Netter wanted to show here with this image that it is located behind the head of the pancreas, then the posterior duodenal pancreatic arch. Now, how is the anterior duodenal pancreatic arch formed?
Well, it is formed with the anterior superior pancreatic duodenal arteries and the anterior inferior pancreatic duodenal artery. The anterior superior is a direct branch of this artery, which is the gastroduodenal artery. The antero-inferior duodenal pancreatic leaves what is the inferior duodenal pancreatic trunk, which in turn leaves the superior mesenteric artery.
Then, in this anterior-inferior pancreatic duodenal artery the anterior superior duodenal pancreatic joins and makes what is the anterior pancreatic duodenal arch. Now, the posterior duodenal pancreatic arch is the same, that is, it is formed by the duodenal pancreatic artery, this time it is the superior porter branch of the gastroduodenal along with the inferior posteroduodenal pancreatic artery that spills from the inferior duodenal pancreatic artery that to its Sometimes it is branches of the superior mesenteric. Then, this would form what is the posterior duodenal pancreatic arch.
In addition to this, the body and tail of the pancreas are supplied by branches of this artery, which is the splenic artery. It would then be through the dorsal pancreatic artery, which is the one you see here, larger, this one, which would be the greater or magna pancreatic artery, and this one you see here, which would be the inferior pancreatic artery. All these little twigs you see here are called caudal pancreatic arteries.
This more distal portion of the inferior pancreatic artery, called the tail artery of the pancreas, also helps supply blood to that portion of the pancreas. I have a posterior view, this would be the head of the pancreas, here more or less the neck of the body, this would be the duodenum, this would be the superior mesenteric and this would be the celiac trunk. Notice how the gastroduodenal gives rise to the posterior superior pancreatic apparatus, which joins the inferior posterior duodenal apparatus, which is a branch of the superior mesenteric and forms the posterior duodenal pancreatic arch, while the arch forms everything in the anterior here as we are.
Seen from a posterior view, this is the one that is clearly formed by the anterior superior duodenal pancreatic and the inferior anterior duodenal pancreatic. This would be the dorsal pancreatic artery, this would be the great or greater pancreatic artery and all of this is the inferior pancreatic artery. All of these little ones that come here would be the caudal pancreatic arteries.
Venous drainage is basically drained by the pacreatoduodenal veins, which are the two arches, one anterior and one posterior, that drain at the level of the portal vein and the superior mesenteric vein and are also drained by the splenic vein. You already know that it is the one that joins the most centric upper vein to later form the portal vein so that all the venous drainage of the pancreas ends up reaching directly or indirectly what is the portal vein and with it the liver. The innervation, as in an autonomous organ, is innervated by the sympathetic and parasympathetic systems.
The sympathetic innervation is given by what are the ganglia of the celiac plexus and the large ganglia of the superior mesenteric plexus and the parasympathetic comes through what is the vagus nerve, that is, through the vagal trunks that have previously migrated to the stomach and on their descent they take advantage of and innervate the duodenum and innervate what is the pancreas. So, this has been the entire video friends, don't forget to subscribe on the Circle the video here and don't forget to follow me on Instagram at @juan_sanchez1315. Here I will leave the videos of the duodenum, the videos of the bile ducts and the small intestine so that you can understand very well or completely what is so important about the pancreas.
thank you very much to see!
