• 3 months ago
HEALTHY HABITS:
Healthy habits change your life.

https://rb.gy/qm6cbt
The Ultimate Healthy Habits Ebook⚡️
"The Ultimate Healthy Habits Ebook" is your go-to guide for transforming your lifestyle. It covers nutrition, fitness, sleep, and mindfulness, offering simple, actionable tips to help you build lasting, healthy habits for a better life.

https://bitly.cx/MoRg
Keto Desserts - High Converting Keto Desserts Offer
Book (printed).
"Keto Desserts" is a high-converting printed book packed with delicious, low-carb dessert recipes that fit perfectly into a keto lifestyle. Satisfy your sweet tooth without compromising your diet!

https://bitly.cx/WrAJ
Home Doctor – BRAND NEW!
Book (printed)
"Home Doctor – BRAND NEW!" is a printed book offering practical medical advice for treating common health issues at home. It includes step-by-step guides, natural remedies, and essential tips for everyday emergencies and ailments.

https://bitly.cx/QqkC
12 Fitness Videos
Downloads.
"12 Fitness Videos" is a comprehensive video series designed to help you achieve your fitness goals. Featuring a range of workouts from beginner to advanced, these videos provide effective, easy-to-follow routines for every fitness level.

https://rb.gy/b01vbi
Lost Frontier Handbook
Book (printed).
The "Lost Frontier Handbook" is a printed guide that teaches essential survival skills and self-reliance techniques from a bygone era. Learn to thrive off the grid with practical advice on homesteading, foraging, and more.

https://rb.gy/jle6zd
Herbs For Health - Only Herbal Remedies Offer!
EBooks.
"Herbs For Health" is a unique guide focusing solely on herbal remedies. Discover natural, effective treatments for common ailments using herbs. This offer provides a wealth of knowledge on holistic healing and wellness.

https://rb.gy/ujlkti
Silence Tinnitus and Hearing Issues with Zeneara!
Supplements - Health.
"Silence Tinnitus and Hearing Issues with Zeneara!" offers a natural supplement designed to support ear health and reduce tinnitus symptoms. Experience relief with this carefully formulated blend of herbs and nutrients.

https://bitly.cx/mLHve
EMFDEFENSE™ Negative Ions Sticker
The EMFDEFENSE™ Negative Ions Sticker is designed to protect you from harmful electromagnetic frequencies (EMF) by emitting negative ions. Easy to apply on devices, it helps promote wellness and balance in everyday environments.

https://rb.gy/38zkvk
SurvivalMD
Book (printed)
"SurvivalMD" is a printed guide that provides essential medical knowledge for emergency situations when professional help isn't available. Learn practical, life-saving medical skills to manage health crises during disasters and off-grid living.
https://bitly.cx/mw6D
Old School New Body
EBooks
"Old School New Body" is an ebook program designed to help you lose weight, build muscle, and slow aging using proven, old-school fitness techniques. It features easy-to-follow workouts and nutrition tips for lasting re
Transcript
00:00One of the reasons I think I'm still in Swansea is because of those beautiful views and being
00:20by the sea. I think I'd miss living by the sea if I wasn't living by the sea anymore.
00:25Anyway, this week I'm going to talk about the pancreas. We've been doing various gastrointestinal
00:41tract stuff the last few weeks. There are a whole bunch of accessory organs or associated
00:47organs of the GI tract and the abdomen. Let's have a look at the pancreas. It's another
00:50one of those organs that's absolutely vital for life but you might not know where it is
00:55or exactly what it does. So, the pancreas. Let's have a look at its structure, its parts,
01:06where it is. We'll have a look in the abdomen and see what is around it so that if you're
01:10then looking maybe at transverse CT scan images or transverse MR images you can work out where
01:16the pancreas is because it's kind of just a squidgy bit of tissue, a squidgy bit of
01:19soft tissue, but you can work out where it is in relation to the other organs around
01:22it. We'll look at the blood supply. We'll look at where it is in relation to the GI
01:28tract. We'll talk about its exocrine function, its endocrine function. We'll have a little
01:31look at the histology, a little look at the cells and the ducting and stuff and we'll
01:36talk about what happens when it doesn't work quite how it should work. Shall we?
01:40So, let's have a look and see where it is first. You can see the lab's got a bit of
01:43a funky set up today. We're in the middle of a formative exam week for the first years
01:47so the room is set up for OSCEs. You know OSCEs? Like clinical skills exams? So you've
01:52got, you can be poking and prodding each other and actors and that. Anyway, it's tomorrow
01:58I think so I'd better tidy up after myself. Right, there's the liver. So we're taking
02:02the liver out. Remember the liver is wrapping around the inferior vena cava. So the inferior
02:07vena cava is going up there into the heart. Here's the stomach. Notice we've got the diaphragm
02:12here. So we've got a series of ribs here. Look, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11. So
02:20there's the spleen around here, right? 9, 10, 11th ribs. So you see the level we're
02:27at? If we take away the stomach, now we see the pancreas. Here's the pancreas here. Right,
02:37so there's the large colon there. There's the greater omentum on that side. Here's
02:41the pancreas and here's the spleen here. The esophagus is just poking out there. This
02:49is kind of diaphragm curving around behind it. If I take off, so if I'm taking off the
02:59pancreas, here's the left kidney here, there's the left adrenal gland. So the pancreas is
03:05cutting across the upper half of the left kidney, isn't it? Right, and notice how here
03:16we've got the abdominal aorta and the inferior vena cava and these are the branches of, look,
03:22there's the celiac trunk, there's the superior mesenteric artery and there's the inferior
03:27mesenteric artery there. So the pancreas is overlying all of that stuff. And most of these
03:33things, so the stomach and the large intestine and the small intestine, of course, are within
03:37the peritoneal cavity or within the greater sac. Where's the pancreas in relation to the
03:42peritoneum then? Well, it's retroperitoneal. So the peritoneum is covering the pancreas
03:47and it's covering the kidneys. And the stomach is then attached to the spleen and the posterior
03:52abdominal wall by mesentery. So the stomach is within the peritoneal cavity but the pancreas
03:58is retroperitoneal. And we can see, here's the duodenum here and it's curling around
04:04and we can't see all of it because the large intestine's in the way, but the pancreas is
04:09nestled into the curve of the duodenum. So the duodenum is partly retroperitoneal and
04:15partly in the peritoneal cavity. We can see up here, there's the celiac trunk and it's
04:21giving off some blood vessels there. So if I take this model, which is some of that stuff
04:41taken out, right? You can see there's the pancreas here and there's the duodenum curling
04:45around it. And the duodenum is really important to the pancreas. The pancreas is really important
04:50to the duodenum. The pancreas itself has a head at this end and what we call an unsunit
04:56process which is difficult to see here, but there's a bit of pancreatic tissue hanging
05:01down here into the curve of the duodenum. So it's got the head and then the neck and
05:05then the tail of the pancreas extends out into the hilum of, this is the spleen here.
05:10And we can see the blood supply to the pancreas quite nicely. This is it here. Now, as I said,
05:17that's the celiac trunk, which is here coming out of the abdominal aorta. And the celiac
05:23trunk then is giving off a number of arteries, but one of its arteries is this one here.
05:26This is the splenic artery and clearly it's supplying blood to the spleen over here. But
05:31the splenic artery is running along the superior edge of the pancreas. And in fact, when we
05:37look at this in cadavers and in people, we see that it's kind of wiggly. It's kind of
05:41a wiggly artery and it's maybe a little bit embedded in the tissue around here. Just on
05:47the other side there, posteriorly, here's the splenic vein draining blood from the spleen
05:52back to the portal vein. In fact, the portal vein forms as the splenic vein joins with
05:56the inferior mesenteric vein here and there's the superior mesenteric vein joining with
06:01it.
06:06So the blood supply to the pancreas then is from the celiac trunk. We do have these pancreatic
06:14duodenal arteries here looping around. We've got superior and inferior. We've got anterior
06:21and posterior. They're largely supplying blood to the duodenum as much as anything else,
06:25but obviously they're probably going to be supplying blood to the head of the pancreas
06:28in the incident process as well. But it's this splenic artery that here that's sending
06:31off lots of little blood vessels into the pancreas and that's supplying blood to the
06:34pancreas. And then the splenic vein is draining blood from the pancreas. And that's really
06:38important because the pancreas, it chucks out a load of hormones, right? So it does
06:44stuff with the blood and does stuff with other bits of the body, which leads us into the
06:49functions of the pancreas. So if we look at the cells within the pancreas, we find two
06:56types of cells, two groups of cells. We find that most of the pancreas is made up of exocrine
07:03cells. So exocrine cells, exocrine means to be secreting through a duct onto an external
07:10surface. And in the case of the pancreas, it's these exocrine cells are producing a
07:15secretion that's secreted into the GI tracts. And the GI tract, the gastrointestinal tract
07:21is considered an external surface within us, right? An external internal surface, right?
07:25There's a tube running through us, open either end. See what I mean? Most of the cells of
07:32the pancreas are making pancreatic juice, this exocrine secretion that's secreted into
07:38the duodenum and that aids with digestion. And then within the pancreas, we see clusters
07:45of cells, little islands of cells, which get called islets or islets of Langerhans after
07:49the guy that first described them. And in those islets, we find endocrine cells and
07:57those endocrine cells are secreting hormones. So endocrine means to be putting something
08:02into the blood that affects other parts of the body. So the endocrine cells, we have
08:07alpha, well, we've got alpha cells, beta cells, and delta cells. They're the ones right to
08:11start with. Alpha cells produce glucagon, beta cells produce insulin, and delta cells
08:18produce somatostatin. So this leads us to probably the most famous function of the pancreas
08:24and that's regulating blood glucose. So glucagon is secreted when blood glucose levels are
08:33low and they encourage the release of stored glucose, as in glycogen, to be released from
08:40things like the liver, where glycogen is stored, into the blood. So the glucose levels come
08:46up again, right? Because you use glucose as an energy source for all your cells around
08:49the body. Insulin does the opposite. So you just had a big meal, all that's been digested,
08:55you got loads of glucose in your blood. Insulin goes into the blood and tells all the cells
08:59of the body, liver and other things as well, to take that sugar and store it away. Store
09:04that glucose as glycogen for a bit until we need it. So that then brings the blood sugar
09:08levels down. So glucagon and insulin work in opposition to manage blood glucose levels.
09:14Obviously there are other parts of the body involved in this. But it's in type 1 diabetes
09:19where beta cells of the pancreas are destroyed, it's usually an autoimmune thing, right? And
09:27someone then doesn't have enough beta cells, doesn't produce enough insulin. So then they
09:32have to do this manually. They have to manage what they eat and they have to inject insulin
09:37regularly to manage their blood glucose levels themselves, which is an arduous process. You
09:42have to measure your blood glucose and keep track of that and, you know, it's a bit of
09:47a pain. Type 2 diabetes is different. That's where the cells of the body start to become
09:53a bit indifferent to insulin and just say, we see sugar all the time, it's cool, don't
09:58worry about it. And you get a whole bunch of other problems. But type 1 diabetes is
10:02caused by a loss of beta cells in the islets in the pancreas, so you can't make enough
10:08insulin. Now there are also gamma and epsilon cells. Now somatostatin produced by the delta
10:15cells generally suppresses the production of all the gastrointestinal hormones. So we
10:23talk about the GI tract and the pancreas as well. They're innervated by sympathetic and
10:27parasympathetic nervous systems and we talk about the parasympathetic nervous system as
10:31being involved in rest and digest functions, right? So parasympathetic innervation stimulates
10:35the GI tract to digest stuff and absorb stuff, right? But in fact, a lot of these organs
10:43and a lot of these secretions and a lot of the control is actually endocrine. So there
10:48are hormones secreted and these balances of hormones, we've got the pituitary gland and
10:51other bits of the body, they all work together in concert to manage the activity of the GI
10:56tract. So somatostatin will slow down the activity of the stomach and hormones being
11:04produced by other parts of the GI tract and that sort of thing. And the somatostatin will
11:08also affect the production of glucagon and insulin, right? So we've got all these. Right,
11:12if I start talking about physiology, we will be here all day. The gamma cells make pancreatic
11:17polypeptide which also regulates activity of pancreatic endocrine cells and the epsilon
11:25cells make ghrelin. Ghrelin is most famous as being like the hunger hormone, regulates
11:31appetite, right? So if you've got lots of ghrelin, you feel full, you feel saturated,
11:37you feel, you know, something like that, anyway. So those are the endocrine cells of the pancreas
11:43within the islets of Langerhans. Now the exocrine cells, we've got these secretory cells kind
11:50of arranged in like around an acinus, right? It's kind of on a curve and they're secreting
11:56into a space and then that, what they secrete into, that space goes into a duct and that
12:01duct goes into other ducts and other ducts and other ducts and eventually you see this
12:05duct here. So this is the main pancreatic duct running the length of the pancreas. We've
12:11got this herringbone shape because we can see the other ducts ducting into it. The exocrine
12:15secretions of the pancreas are things like trypsin, chymotrypsin, amylase. And we've
12:21talked before about how, so trypsin and chymotrypsin are proteases, so they break down proteins.
12:30You're made of proteins, so proteases are quite dangerous to you, right? So we've got
12:34a tissue secreting dangerous things that could break the tissue down. So they're secreted
12:40by the cells and they're packaged up nice and tidily in an inactive form and then they
12:45pass along the main pancreatic duct and are secreted into the duodenum here and it's in
12:51the duodenum that they get activated. Again, more physiology. You want to know how? That's
12:56another day. So these enzymes, ideally, they get activated in the duodenum and then those
13:02proteases can break down the proteins. We've also got pancreatic lipase that's going to
13:06break down fats. We've got amylase that's going to break down starches into, what, maltose?
13:17We've got gelatinase, elastase, you've got deoxyribonuclease and that sort of thing.
13:25So there's a whole bunch of things being secreted by the pancreas that help with digestion in
13:28the duodenum. That's the important bit, right? So these exocrine secretions from the pancreas
13:32secrete into the duodenum. Now, can you see there's two ducts here? There's a main pancreatic
13:37duct which is actually the inferior one, the lower one here. Then there's an accessory
13:41pancreatic duct here which is a little ditty one. Now, this occurs because in the embryo
13:48there's a simple gut tube and it's held in place by, up at the level of the stomach,
13:54there's a posterior, like a dorsal mesentery, which we call the mesogastrium, gaster, because
13:59it's next to the stomach. And there's a ventral mesogastrium, because it's at the level of
14:03the stomach, between the future stomach tube and the anterior abdominal wall. And then
14:08we see a couple of buds growing from the early GI tract. And those buds go on and form
14:14various things. They form the liver and the gallbladder and they form two pancreases.
14:20So there's an anterior pancreatic bud and there's a posterior pancreatic bud, or dorsal
14:24and ventral if you like. And then the stomach, right? The stomach rotates around and pulls
14:30the duodenum with it and stuff like that. And when it does that, it brings these two
14:34pancreatic buds around and they meet together. So that's why, when we look at the adult pancreas,
14:42we see two ducts, because really the uncinate process down here, that's kind of the other
14:46bud, right? The little bud. And this is the big bud, the big pancreatic bud here. Those
14:51two pancreatic buds have been brought together and they have their own duct because that's
14:55how they formed. They ducted from the GI tract and then they formed. Basically, this is endoderm
15:02because this is the GI tract, so endoderm is forming the innermost layer. And then the
15:07cells of the pancreas are formed from endoderm. They follow different differentiation pathways,
15:10whether to become exocrine cells or endocrine cells, and then further differentiate it into
15:14becoming all those different cells we've been talking about. Anyway, so this main pancreatic
15:23duct in most people collects most of the exocrine secretions and ducts into the duodenum here.
15:35And the other thing is, right, you see the green tube here? Now, I said that the gallbladder and
15:40the liver also grow out in the same outpouching, right? So there's another tube connecting the
15:45gallbladder and the liver because bile comes from the liver, right? And then backs up and
15:50gets stored in the gallbladder. Anyway, this is the common bile duct. So the bile duct also loops
15:56around. The bile duct and the main pancreatic duct both duct into the duodenum at the same point
16:02through the same hole. Now, the common bile duct has its own sphincter of smooth muscle,
16:08which it can close off. And the main pancreatic duct has its own sphincter of smooth muscle,
16:13which it can also close off. But it's obscured by this blood vessel here. But just before
16:20those two ducts come together and duct into the duodenum at the same place, there's an ampulla.
16:25So an ampulla, ampule, right? You know, it's, you've got a tube and it kind of, you know,
16:33right, ampulla, kind of a little bit of a dilation of a tube. So there's a hepatopancreatic ampulla
16:41as those two tubes meet, which also, which used to get called the ampulla of Vata.
16:47And then they both, around the ampulla of Vata or the hepatopancreatic ampulla,
16:53there's another smooth muscle sphincter, which is the hepatopancreatic sphincter
16:58or the sphincter of Ody, which is a great name, but it is his old name.
17:04So all those sphincters then can control the flow of exocrine pancreatic juice into the duodenum
17:11and bile from the common bile duct into the duodenum. And that's what we see in about 90%
17:18of people, we see that organization. And this accessory pancreatic duct up here
17:22just drains his pancreatic juice into the main duct and it pops out there. But in about nine
17:27or 10% of people, you'll see a second opening up here in the duodenum. This is the descending or
17:33second part of the duodenum, by the way. And there will be the accessory pancreatic duct will open
17:40at an accessory papilla. So there's a little papilla, a little mound
17:46in here where the main pancreatic duct opens in some people. And in fact, on this model,
17:52there is a second opening there. So if you're doing an endoscopic process and you're looking
17:58down the duodenum and you find one opening and then you find a second opening, that's fine.
18:04It's not terribly unusual. So that's how the exocrine secretion of the pancreas gets into
18:09the duodenum. The endocrine secretion goes straight into the blood. All right, so that's
18:12some of the functioning of the pancreas. Now we were looking at structures nearby.
18:16There's another cool thing to notice. So you remember that the abdominal aorta is running
18:24just posterior to it and we can see the celiac trunk here. Now that we've talked about the
18:29duodenum curling around and the pancreas running across, can you see here? Look how the
18:36superior mesenteric artery and superior mesenteric vein appear from between the pancreas and the
18:46duodenum and then they run anteriorly. So that's another good landmark. That's how you find the
18:50superior mesenteric artery, right? Oh, also the epithelial cells of the pancreas make bicarbonate.
19:01Stomach makes acid, bicarbonate neutralizes the acids from the stomach, comes from the pancreas.
19:07So what could go wrong with the pancreas then? Well, we've already talked about diabetes
19:11and loss of the beta cells, loss of the ability to produce as much insulin as you need.
19:17Actually, from a tissue engineering standpoint, now that you know about the embryology,
19:25it would be possible, wouldn't it, to take embryonic stem cells and then differentiate
19:30them into endoderm and then into, you know, down a GI tract pathway and into pancreatic cells and
19:37you could, if you could work it out, you could cause these cells to differentiate into
19:42beta cells and you could take your population of beta cells and say inject them into the portal
19:48vein and they would seed the liver or something like that and then the patient would have
19:55beta cells and they could produce insulin. Would that be a cure for type 1 diabetes? Maybe.
19:59People have already tried that and it seems to be working. I think the latest idea is to
20:04package these cells in a different manner and put them under the skin and what have you, but
20:08cool, huh? Tissue engineering, got to understand the embryology and blah blah blah blah blah.
20:13So that's type 1 diabetes. Now, because the bile duct and the main pancreatic duct are ducked
20:21into the duodenum in the same place, you've heard of gallstones, right? So you can get stones in the
20:28biliary tree in the bile duct. You get them in different places and it's possible, of course,
20:32that the bile stone, if it's formed higher up, could move down the common bile duct. So it's
20:36possible that you could get a gallstone lodging in here, say in the hepatopancreatic ampulla,
20:43which would not only prevent bile from going into the duodenum, but it would also prevent
20:49exocrine pancreatic juice from passing from the pancreas into the duodenum.
20:53Now, what do you think that would lead to? Well, you'd get, you know, you wouldn't be able to get
21:00rid of all the bilirubin from the liver. So you start to get rising levels of bilirubin, so the
21:07colour of the skin would become yellow, would become jaundiced, right? So you'd see some liver
21:11dysfunction, but also you'd start to see signs of acute pancreatitis. You'd start to get inflammation
21:16of the pancreas and damage to the pancreas, which would be bad. You can get acute pancreatitis for
21:22other reasons as well. So, you know, I said that we've got these dangerous proteases, these enzymes
21:28which could digest tissues, proteins of the pancreas, and they're packaged up and then released
21:35safely into the duodenum. Well, if that process is broken down, if that packaging isn't made correctly,
21:41if those proteases, if those dangerous enzymes aren't safely packaged away, then they can
21:48damage the pancreas. And then you'll see inflammation of the pancreas. And again,
21:53acute pancreatitis, you kind of get this pain developing and this sort of thing. So acute
21:58pancreatitis is dangerous, and it has something like a 10% mortality rate, so it's very dangerous.
22:05And you usually get like an onset of mild pain, which gets worse and worse and worse.
22:10The pain gets worse with eating. Makes sense, because of course you've got all the triggers to
22:16make your pancreatic juice and secrete it and put it in the duodenum, but it can't get into the
22:19duodenum. Or it's damaging the pancreas, so pain increases. People tend to be very, very
22:24ill with acute pancreatitis. You have to go to hospital and often get a nice surgeon to help you
22:30out. So acute pancreatitis can be caused by a couple of things. Think gallstones here, and think
22:37poor packaging of those dangerous enzymes. So that might be a result of use of a certain drug,
22:41or alcohol, or you know, something like that. What else? Oh, pancreatic cancer. Pancreatic
22:50cancer is very, very dangerous. Acute pancreatitis can be difficult to diagnose,
22:57because there's a lot going on around here. Pancreatic cancer likewise can be very difficult
23:03to spot and to diagnose. If the cancer forms up here somewhere, then the pancreas is probably
23:08functioning just fine, and there are very few signs that there's a tumour forming in the pancreas.
23:13And the tumour can spread quite easily from the pancreas. Now, if the tumour forms in the head
23:17of the pancreas, that's better, because it's going to block the ducts down here and may lead to signs
23:26of acute pancreatitis and jaundice much earlier. So you get an early sign of a problem, and then
23:32you can hopefully diagnose pancreatic cancer and remove it early. But the reason pancreatic cancer
23:37is so dangerous is because it'll often form in the tail of the pancreas and give virtually no
23:44warning signs at all, and it'll get larger and spread. So it has a very high mortality rate. I
23:49think you get, does it get called the silent cancer or something like that? So pancreatic
23:54cancer, very, very dangerous. So how's that? We've looked to see where the pancreas is.
23:59So if you're looking at a transverse section of the abdomen on CT or MR, for example,
24:05then look for the pancreas posterior to the stomach. The stomach you might see as a dark
24:12space with air in it. Anterior to the aorta. You should be able to spot the aorta and the inferior
24:18vena cava. Anterior to the kidneys. Those are your landmarks, right? So anterior to the left kidney
24:24there. And if you've got the spleen in your section, you're probably too high. We've talked
24:29about the functions of the pancreas generally. There's a huge amount of physiology going on
24:34there, but that's somebody else's job. We've talked about what can go wrong with the pancreas.
24:37We've talked about the blood supply. I briefly talked about the innervation. So there's
24:42parasympathetic and sympathetic innervation to the pancreas, but most of the control of the
24:46pancreas is endocrine. It's under hormonal control. Parasympathetic innervation is through
24:52the vagus nerve, of course, everything through the vagus nerve down here. And there you go.
24:57So quick overview of quick. Yeah, when do I ever do anything quick? Look at the anatomy of the
25:04pancreas. Hopefully it'll serve you in good stead. Right, what's left in the abdomen to talk about
25:10next time.
25:40Bye.