welcome back welcome back welcome back to science today we're going to be talking about the pancreas the pancreas has a major role in human health and it said that in the next 10 to 20 years that the amount of people with type 2 diabetes will increase by 400 percent and as astronomical and why I'm even talking about that is it ties into the pancreas the pancreas is going to have both endocrine and exocrine action remember that endocrine is going to be directly absorbed into the bloodstream where exocrine is going to use tubes and ducts to empty into things so in the endocrine side of things we're going to have both insulin and glucagon that's going to be involved here insulin's purpose is to open up channel proteins on the side of cells that allow for sugar molecules to go from ins outside of the cell to inside of the cell as a result blood that is high in sugar will have that Sugar move in to the cell instead of being on the outside of the cell this is going to reduce the blood sugar so this is how insulin changes blood sugar on the contrasting side of things you have glucagon glucagon is going to be released Whenever there is low amounts of sugar so when you're hypoglycemic it's going to be noticed by the body and the body is going to tap into sugar reserves sugar reserves are stored in areas of the muscles and liver in the form of glycogen glycogen is broken down into smaller glucose molecules sugar carbohydrate that can be broken by this down by the cell to produce ATP now if we look at the exocrine part of this this is where we're going to more Focus today because this is a pathway that we're going to start to look at so most of the pancreas is made up of these pancreatic acid our cells so they're going to release tiny amounts of pancreatic juice and to these tiny tiny ducks and these are going to be that pancreatic duct essentially there's two major ducts that you're going to see in the pancreas the accessory and you have the main so the pancreatic duct you're going to have it's going to move with something called the common bile duct let's take a look at it so here is the common bile duct you can see the left and right hepatic ducts that are going to be here emptying into the common hepatic duct you can see the gallbladder emptying the bile and to the bile duct and this is all going to move down together right here and join right beside this and if you zoom up on this zoom and here we get to the structure here so we have the structure where we have the ampulla which is this opening here and you have these flap-like papillary that develops this Lumen you're going to have a bigger one which we're looking at here and a minor one that's going to be here this is the minor duodenal papillary and this is going to be the major duodontal papillary so you're going to have the major pancreatic duct here's the accessory duct that's going to be emptying off here's the major pancreatic the main pancreatic duct and the bile duct they're going to move together and they're going to release in this area notice the Shaded green this is just showing that the release from this is going to be in this area the release of this is going to be in this area so pancreatic duct along with a common bile duct from the liver and gallbladder is going to empty into the duodenum of the small intestine the pancreatic duct and the common bile duct are going to join a dilatitude called the hepatopancreatic and Pula so this is also called the hepatopancreatic impula of Vader all right so that duct making these things are going to flow into the duodenum but how do you regulate it you're going to regulate it with a circular muscle that's going to go around this that can constrict it and even choke it off this is called the Paco hepatopancreatic sphincter of ODI so this is going to go around the impely and you can see the circular muscles there and the hepaco hepatopancreatic sphincter that's going to act as a valve to close that off and so this is going to keep those gastric juices and pancreatic juices from entering into the duodenum if you don't need them there once again our body is trying to only add whatever it needs to add and so if there is a sense of food a kind that's moved into this that is post pyloric sphincter from the stomach and the duodenum then you're going to have the release Here we're also going to have some other pancreatic juices so what is in the pancreatic juice it's able to break down all of the macromolecules carbohydrates fats proteins nucleic acids so let's look at some of those examples of those so pancreatic amylase we've seen ambula amylase before we've saw this in the form of salivary amylase and we know that amylase is going to break down the sugar called amylose amylose is the scientific name for starch and so pancreatic amylase breaks down starch into smaller disaccharides that are more digestible by ourselves all right pancreatic lipase lipase is going to bake break down lipids lipids once again is glycerol and Three fatty acids it's going to help break down that triglyceride now trypsin a trypsin is going to be a major trigger here um and this major trigger is going to be something needed for these others to work so in general trypsin breaks down protein and you may think of a way that I remember that is of the 20 amino acids its namesake is really close to a couple different amino acids so that's the way I remember it is I've seen many of these amino acids and you probably could look through and like okay I can remember it that way all right so by the releasing of trypsin trypsin is going to be activated by enterokinase so enter kinase is going to be produced in the small intestine and the glands of Bruner and I believe your book just goes generic and says in the mucosal lining of the small intestine of the duodenum so trypsin is made by that by the small intestine itself by making this you can take something called chymotrypsin that can be activated for the breakdown of protein you also have something called carboxyl pepsidase which also breaks down protein it too will be broken down by trypsin excuse me we'll be activated by trypsin so we have chymotrypsin and carboxyl pepsidase which are going to be activated by trypsin and trypsin is going to be activated by enterokinase and enterokinase is going to be produced by the inner lining of the small intestine and so by releasing of the enterokinase by the small intestine you're going to activate trypsin and trypsin is then going to activate other things like cometrypsin and carboxypepsidase so kind of neat we see a chain of events that occurs all right nucleases break down nucleic acids and finally we have bicarbonate ions bicarbon ions I I think most people would be thinking about this but your your digestive juices of your stomach um that pepsin that's there that's activated by the hydrochloric acid that's there you're emitting some of that hydrochloric acid into your small intestine and one with you know me to think like why don't we digest our own small intestine with the digestive juices I mean we could literally um eats the intestines of an animal and digest it so how are we able to digest intestines while we don't digest our own intestines so part of that is bicarbonate ions by adding these bicarbonate ions it's going to neutralize that acidity and cause it to become much more alkaline in nature and this is going to buffer the stomach acid so bicarbonate ions are going to be one of those like hey let's just calm that acid to be more of a neutral pH all right so hormones we have secretin and cholesteroline also called cck so we have secretin it's secretin stimulates the pancreas to release pancreatic juices high in bicarbonate ions and we've already identified why the bicarbonate matters cholesterol Kylene cck stimulates the pancreas to release the gastric juices that are high in enzymes the nervous system also is involved in this once again rest and digest during the cephalic phase we're going to have taste smell sight this is going to be a part of it and also the gastric phase the parasympathetic impulses are going to stimulate the pancreas to secrete digestive enzymes if you're parasympathetics are like suppressed because of it it is a stressful situation you don't have much digestion and so in high stress situations let's say you're very very stressed um your GI tract isn't really active and if food is moving through it oftentimes a person under high stress has an upset stomach because they're not able to digest their food and absorb things as they would with the normal rest and digest of the sympathetics so here is an overview acidicime is going to enter into the duodenum we have the accessory we have the main and we have the hepatopancreatic duct that's going to be here at the simpler and we have intestinal mucus is going to secrete basic release of into the bloodstream secretin is going to cause secreting it's going to stimulate the pancreas to release the bicarbonate and so by having chyme this is triggered the pancreas to go and start releasing so pancreatic juice rich in bicarbon ions passed down the pancreatic ducts to the denim where it actually can neutralize the acidity of that kind all right guys next we're going to be on to the liver and gallbladder I'll see you there