okay let's pick it up with the small intestine we've made our way through the stomach and we're fixing in turn into the small intestine we got three different parts to the small intestine that you can see the first part that's gonna be this first a little bit here this is the duodenum because this is the mixing bowl because when I'm gonna do a lot of absorption here but we're gonna do a lot of mixing thank the second part of the small intestine is the Jew gentleman the Jew genom and then underneath the Jew Jenna we have the ileum and we've had an ilium before but that was a bone in the pelvis this is spelled differently this is with an Inanna okay while we're here let's look over here to the right-hand side and let's look at some structures that we're going to find more in the jejunum than the duodenum these are called the plaque a the plaque a circulars and these are these little flaps that you see on the inside they go all the way around and they're going to increase the surface area for absorption when we get to the small intestine so one of the make you aware of those on this picture and then we'll talk about them again as we go a little bit further down okay small intestine plays a role in digestion okay utilized here and this is what most of the absorption is going to occur it says 90% of the nutrient absorption occurs in the small intestine we can get some things absorbed in the stomach we see water able to be absorbed across that epithelium we also see alcohol being able to be absorbed once it hits the stomach that's what I say to make sure that you you're going to drink alcohol make sure you have a full stomach that way you don't absorb as much as rapidly into your bloodstream okay like I said the divide about the first 10 inches of the small intestine so as we leave the stomach first 10 inches is at the 1 and you can call it a duodenum if you like it is the mixing bowl is going to receive this fluid food source from the stomach that we call kind and it's going to be mixed with all those secretions all that water all those enzymes that added all of that stuff that we've produced there in the stomach as well as we're gonna hook in the liver and the pancreas here to give us even more secretions into this kind okay then we're gonna move down to the Two Gentlemen it's about eight feet middle section and this is where we're gonna see most of the chemical digestion and the nutrient absorption and then we're gonna make our way down into the ileum which is about the last 11 and a half feet or so and that's going to finish out our small intestine so in the small intestine we're going to see since this is the site for most of the nutrient absorption we want to increase the surface area for this absorption to happen so we're going to see it happen at three different levels the first level is a large structure these are permanent features that we're going to be able to see in the small intestine not gonna disappear when it feels they're going to be those flaps that I've talked about those are called the plaque a circulars and notice that we've got those pn out here we've got those here you can see these flaps in here and what those look like is a big old speedball okay a great big flap to increase the absorption okay so we're not just gonna have this flat surface like this for absorption to happen we're going to increase this okay by having these large black a okay and then on the plaque a are going to place little finger-like projections we call these finger-like projections the v/line okay and these are structural okay they're like little stalactites and stalagmites okay they're coming up and they're also going to remember how microvilli on ourselves increase the surface area well this is at a bigger scale okay these are structures that we can see under the microscope okay and then once the v/line once the pluck a at its first level the second level of the villi the third level let's increase it with the individual cells and we're going to put the micro villi on the cells they host the brush border along a lot of the time but we're gonna have micro villi sticking off of the cells now you can tell that this is simple columnar epithelium up there at the top and we've got a lot of these goblet cells these ones that are kind of clear on the inside and notice they've got a little word that kind of pushes up between the cells to allow the mucus that is produced inside the cell to make its way out onto the surface so you can see these little pores they're going through right here okay so that's our three levels to really increase that surface area okay like I said these are testimo belie this is the second level these are the finger-like structures what we're going to see in some of those microscope slides that I've given you is we can see that this whole structure here is the belie okay that's the B line and then on the inside we can see where there is the lamina propria it has all the blood vessels and stuff like that inside of it and that's what's gonna give our v like its structure all of this in here okay we see some individual goblet cells and you can see all of this is the structural part of that okay with our microvilli on each cell we've also show those goblet cells that we looked at each one of these is a goblet cell that produces that mucus onto the surface that's going to be very protective and allow things to flow across it very easily so when we think about the duodenum we're not doing a lot of absorption here so we don't need to pluck a so we're gonna see very few pluck a in our duodenum and likewise the meal I are not really there for a lot of absorption here so what the vlive they're small and by that we mean they're nice and skinny they're kind of pokey like this if you look at the meal I on the slides that I've given you for lab they're gonna be the long and tall feel I like this okay because that function is we're doing the mixing here we're not doing a lot of absorption so we've got to do things like neutralize the acid that is in that stomach that hydrochloric acid because it's making its way into the small intestine so the first thing we got a neutralized it so we don't burn up the absorptive cells of the intestines okay so in this intestine we're going to produce even more fluid we're going to add another 1.8 liters a day to the fluid that's going to be inside the intestines okay that's going to help moisten the time even more it's going to help buffer okay and it's gonna keep those digestive enzymes in solution we want them to be in solution so that it's mixed well so that we can absorb it by doing this it's gonna come in contact with all those absorptive cells better if it stays in solution so they're gonna keep moving it around it's going to keep sloshing around in there and it's gonna keep all through the environment as absorption is taking place we're gonna get to mix it so that we've got plenty of absorption to take place remember this is key for us this is where we're getting all the good stuff okay so we see weak peristaltic movements happening here once the food or the calm reaches the duodenum it's going to move it very slowly giving us plenty of time to do nutrient absorption one of the accessory organs that we're going to dump here into the duodenum and you can see this we want them here okay is the pancreas okay pancreas is one of those organs that we can't live without okay it has a head region the body and then toward the end look at the tail okay and it's job is to different functions one of those functions is it is going to be exocrine in function the other it's going to be intercom function exocrine means we're going to dump the digestive enzymes that are produced by this organ we've got a duck system that runs through that attaches into the duodenum and you see this little hole that allows for it to make its way in we call that the duodenum delay okay and this duct we call the pancreatic duct okay so there are different kinds of cells inside of our pancreas all of these out here these are the seamy cells okay the acini cells they're telling us down here the acini cells the other ones are found in these little globs and they're a little bit smaller they're a little bit more grainy looking to me we call that a pancreatic insulin this is the says I look there but everybody says islets okay and it is the hormone production okay and what hormones are we going to put into the bloodstream from the pancreatic insulin that's gonna be our glucagon and insulin and that's gonna control blood sugar okay the assini cells this is where the digestive enzymes are going to be produced and this is gonna be dumped in here so one is dumping into the duodenum that's the assini cells the other the pancreatic insulin that's hormones that's endocrine that's gonna go into the bloodstream okay so pancreas as you show you the head kind of tucks into that duodenum okay it's a little thin capsule around it and body and a tail we looked at that and the pancreatic duct sometimes it's called the deductive or Celyn I don't hear this near as much as I used to when I first started teaching so we're kind of doing away with that and just calling it the pancreatic duct and it's going to deliver those digestive enzymes and the buffers that are made by those Hasini cells okay now in addition to the pancreatic duct we're gonna have another tube join us before we dump it in so you can see the pancreatic duct coming down here and joining into the duodenal papilla but then we also have coming from the liver and gallbladder this common bile duct that's gonna come in here as well and it's going to join with it they're gonna be able to mix at the duodenal A&P late and we've got a sphincter that wraps that smooth muscle around it right here and that's called the hepato pancreatic sphincter a Patou for liver pancreatic for pancreas so we're gonna control this with a smooth muscle sphincter okay so when we loosen the smooth muscle it's going to allow for the release of the bile coming from the liver in the gallbladder and all the pancreatic enzymes okay made by those assini cells in the pancreas okay so we look at the pancreas we can see the difference all of this out here these are in big connective tissue areas that kind of separate everybody but we can see a nice pancreatic islets here we can see one here we can see a nice blood vessel and duct there's the here are some blood vessels they run through in here so we know what those look like so lots of you can see a little bit of a pink red it gets lit rather there so there once you kind of see what they look like it's pretty easy to identify those but by and large what we're producing or the digestive enzymes you can see that there is a lot more cells that are producing the enzymes then there are the hormones okay so a septa like I said that's the connective tissue that is separating them we've got some blood vessels and got some ducks in here the acini all don't be into little tubes that carry its way into the pancreatic duct in the insulin some more scattered throughout here okay and there again their job is not to be digestive system their hormone and they're producing our insulin and glucagon insulins job is to decrease the amount of blood sugar that we have glucagon job is to increase it okay so my wife she has lost her insulin producing cells in the pancreas so she has to give herself insulin she's got a little pump that pumps it in and she can communicate with her pump if she eats something that has a lot of carbs in it she knows she's gonna have to put more insulin into her body so in Durkin cells this in Durkin cell this is the insulin pink I guess what do this job these are the assini cells during the pancreatic digestive enzymes okay so how much do we make in the pancreas we make about a quart or a leader of pancreatic juice a day okay and the duodenum is going to talk to us about this it's no sales okay based on what's in the duodenum we're gonna communicate back to the pancreas and say okay we need specific pancreatic enzymes based on the food that we have eaten okay now we're gonna loosen that have no pain critic specter and that's going to allow us to move this in to the duodenum from the pancreas okay what's the pancreas make it well a lot of stuff okay we see tons of different enzymes produced in fact it's going to make enzymes for every one of the big carbon sources that we use so he's going to have carbohydrates in it that are gonna break down the starches it's going to be very similar to salivary amylase we call it pancreatic alpha-amylase okay we're gonna see lipid breakdown in the form of pancreatic lipase okay this is gonna start breaking down those complex lipids okay and we can even break down nucleic acids with this so part of the DNA we can break these down and utilize the portions of nucleic acids from this okay and then we really make our money in the pancreas with our proteolytic enzymes these are the ones that are going to break down proteins now you might remember we talked about pepsin when we talked about the stomach this is where we're really gonna knock out the proteins okay we've got all kinds of different protease peptidases these are gonna break them down into the individual amino acids so that we can absorb them okay so we're gonna go from big proteins down to the individual amino acids utilizing these proteolytic enzymes and it says 70% of the pancreas is enzyme production is for protein so it's really doing a job of the printing and just like we did with pepsin by secreting pepsinogen as a pro enzyme most of these enzymes are going to be secreted as for enzymes and then when they hit the small intestine they become activated that way we don't digest ourselves we only digest what is in it small Testament okay another one of our accessory organs that's going to dump into the duodenum is the liver and we know the liver is a huge organ we've been seeing it before large visceral organ okay you know where it's located a little bit on the right-hand side of our bodies okay the right side this shows it here and here's the way it's arranged body and we see the different lobes we see a tough fibrous capsule that goes around it there is a ligament called the foul so formal ligament that makes its way through here that separates the right lobe from the left lobe see that here as well okay and then we've got two other lobes so we've got the right lobe we've got the left lobe you can turn it around the back side we can see the caudate lobe and the quadrate lobe okay so that's where these are located quadrate lobe is down here back where we see the gallbladder and all the plumbing for the gallbladder so I always remember that same comes before cube so sees the one above Hughes the one below okay like I said falciform ligament to divide it to the right modes and then on the back side you see the caudate lobe here and the quadrate lobe down here below okay then I've got pictures of those for you in the stuff to know for lab okay so see above cube okay there's you gathered along close to that gallbladder okay we've got a duct system here getting what the livers gonna produce for us is bile okay and what biles job is it is to emulsify fats so it's all about lipids okay so what's gonna happen is the liver is going to produce it they've got a bunch of these little channels that are going to carry the bile once it's been made okay and the little bow canaliculi aren't gonna dump into the duct jewels which dump into the different bile ducts that we have and they're going to merge together in kind of the center portion kind of where that called a quadriga was so we've got a right and I left hepatic duct okay so one from the right hand side so this would come in from the right inside is going to join with a duct coming in from the left hand side okay so this is gonna be our right hepatic duct okay this can be our left of Haddock duct okay and they're going to unite and form a common hepatic duct this is going to be common hepatic duct okay now we've got two ducts that come off here one of them that leads to the gallbladder so here's my gallbladder and this duct here that I'm drawing this is called the cystic duct okay cystic duct okay that's this one here and then everything else continues on down to the small intestine where the duodenum is this one is called the common bile so write a panic duct appear from the rights portion of the liver left a panic duct come together in the common hepatic duct there is a branch that leads to the gallbladder that's called the cystic duct and then everything else can drain the hell into where the small intestine is for that new item is Leah the common bile duct okay that's the way that the flow of the bio happens so common bile duct is formed by the union of the cystic duct and that common hepatic duct okay and it's going to pass within there's a lesser omentum here close to the stomach so to penetrate the wall of the duodenum and meet with the pancreatic duct remember it's going to come down and like this join with the pancreas adding dust below in that little NP lay okay and then there is the dump into the duodenum through that so here's the duodenum okay so you're gonna have bile from the liver coming down you're going to have pancreatic enzymes okay from the paint cutting juice that's making its way in here we've got that a paddle pancreatic sphincter that's going to control it with smooth muscle and that's how it's gonna dump in here okay so the functions of this liver there's a lot and a lot of these we already know okay we know a lot about the properties that the liver does for us with blood okay we'll go over those in just a second there's a bunch of metabolic things that we're going to talk about and the last one is bio production that's that's why I say if we don't know what organ does something because the organ has all of these different functions a good guess is always the liver okay so let's talk about it quick the liver regulates the composition of our circulating blood okay what's made the blood in the form of what nutrients are available to us okay it's able to do waste removal it can store it if we have access and we could do inactivation of drugs okay so from our metabolic standpoint this is big okay now when it says it controls the supply of things to the blood the reason it does this is once we pick up stuff from the duodenum into the bloodstream the first place the blood goes once it has been hit once the nutrients have been picked up okay is a vessel system called the hepatic portal system takes it to the liver so it says all blood leaving the absorptive surfaces of the digestive tract so we've picked it up first place to send it to the liver okay so it gets this fresh all the nutrients going to the liver first and what the liver can do then is it can extract what it wants if there's any toxins in here we can get rid of the toxins so we don't send out to the body okay if we're low on things if we have extra to store we can store it okay so it's basically deciding how much of this nutrients do we need right now do we need it all can we store some I don't want to put a whole bunch out there right now and overwhelm things and I sure don't want to do toxins or anything that's going to be harmful to the body okay so it's the big thing is it's gonna help store things and it's gonna help decide what we need out there the body right now if we've got plenty then we can store it okay then there's metabolic activities in the liver it's gonna be important for carbohydrate metabolism lipid metabolism amino acid metabolism that's the big 30 carbohydrates fats and proteins this is how we're gonna break those down for energy okay it also is important for waste removal vitamin mineral storage and drug and activation so from a metabolic standpoint all those chemical reactions that are going on body livers helping control those okay we know it's a huge blood reservoir in the body 25% of the cardiac output it's leaving the heart in the systemic circulation is headed toward the liver okay that's big okay so we know that those blood related functions of the liver it had a major importance here so we're gonna have macrophages and other cells that can affect a cytosis advantage and presentation in the liver remember that liver makes most of our plasma proteins this is where we can get rid of the hormones that are in excess we can remove excess antibodies we can remove it store toxins here and lastly this is where we're gonna do the production and the secretion of the bile and again miles job is to emulsify fats okay if I'm also fine I mean break big fats down into tiny little droplets of fat so here's the problem with fats we know that there's a problem with lipids and water okay they don't do well in water if they are hydrophobic so dietary lipids they're not water soluble we need a way to deal with these okay the goal is break the large drops down into very small lipid droplets okay that's the job of an enzyme okay lipase to help us break them down so we have to be able to emulsify these go from something with a surface area let's say that the lipid is like this there's a lot more surface area if we break them down in that one big thing into hundreds of these little bitty droplets and now that pancake lipase can work on these a lot better okay because the only place that a enzyme okay can work on this is at the surface of this okay because it's not lipid soluble so we it's in the water it's working on the outside think how long if I can just work on the outside this is gonna take but if I break that big glob down into tons of these little beady droplets now we can turn it all the way around the outside of this okay I'll take forever to get down here in the center of this these are gonna be a lot easier for us to break down so that's the job of bile lipid enzymes can do their job pancreatic lipase into this job okay so here it is bile salts the bile do a multiplication and all we're doing is creating from one big lipid whoa we're making a bunch of leaves a BT tiny limits okay we're going from something like let's say a softball into a whole bunch of bb's that would make up a softball science fiction okay so if we turn that softball into bb's now we've got a lot more surface area for us to attack this in break you bail okay so I had a friend that um had her gallbladder removed and she typically ate a lot of fat and because of that once her gallbladder was removed she didn't have as much viola valuable and I explained the role of the gallbladder in this here in just a second but he ended up where she had a lot more fat remaining in her waist because of this okay so here's a gallbladder like I said and this is a good picture for us to look at those Ducks again so you can see here on the picture here's the left to panic duct come in here here's the right one coming in here they join together we've got the common hepatic duct and then headed from the common hepatic duct this is the cystic duct leading to the gallbladder and then these two unites and then that's the common bile duct all the way down that dumps in finding one okay so the gallbladder is a little pear shaped green looking structure that you can see here this job is to just store and concentrate the bottle it's not producing it and the way it gets it is it makes this fill up and once we get it full we can back load some into the gallbladder here okay and the that that is in here we're able to concentrate it and store it so that we've got a lot of bile left over okay so that we can utilize it if we have a really fatty meal okay and if you take care if you get you better take it out a lot of times the gall stones will cause that to happen the doctor now tell people you want to go the low-fat for a while and let you never pick up on bile production it'll increase the bile production over time okay but you gotta you got to give it about up to a year I think they say before it's really doing the level it needs to without the gallbladder okay so three parts the to the gallbladder the funds the body in the neck okay so the Nick here's it's about to enter into the duct body the main portion of it here and then that portion that rises up that's called the fundus okay then we see that in the stomach as well we'll see it in the uterus will see a fundus and a lot of different things okay so cystic duct that would be the duct that if we were gonna remove the gallbladder they go in make an incision here and tie it off and remove this portion and that still allows us to produce the bile all the way down here anymore because remember this is job is just a store concentrated but we don't have that good concentrated form but if we went and ate it Oh [Music] long john silver's or something and had the captain's platter with extra crunchies that they fried you know you know there's a lot of fat that we have to emulsify so we may not get it all the muscle fiber okay so common bile duct that's the portion that extends from the cystic duct and the common hepatic duct down into the duodenum okay makes its way to view late and that's not something that we can see I've always looked for it on the cat but I've never really been able to find it inside the duodenum of the cat when we've done our dissections okay it goes little hole that's the duodenum okay so the gall bladders job like we said store and concentrate the bile and it is on hormone stimulation the hormone that is going to say release the bile that is cholecystokinin okay cholecystokinin is the enzyme that loosens that hepato pancreatic sphincter and causes more bile to be released and in doing so we're also going to release more of the pancreatic juices as well so we'll have the enzymes to break it down and the bio to emulsify it okay so full gallbladder depending on the size of it anywhere from about 40 to 70 milliliters it's going to change how concentrated it is based on how much water we take away from it okay and if we take too much water away from it okay some of those things start to fall out of solution they start binding together and we call that gall stones it's a bunch of minerals and bile salts that are there okay so when it gets a little bit if the stones get too large okay they can't go through the bile ducts oftentimes we'll see small stones make their way through that's happened to me a few times where I've had that pass gallstone okay they're too big they get stuck in there it doesn't allow your gallbladder to do its job anymore it can actually yeah fairly painful experience when this happens and look at the size of some of these gallstones over here that's an old Nokia phone there look Brussels sprout they're so big okay and then here we see on this other side we see a bunch of these skull stones that are inside this ball bladder that has been removed okay so like we said a lot of solid material minerals things like that by absolves cholesterol things like that are going to be founded here excess body weight makes you at a greater risk for it we see it especially in women leads to upper abdominal pain some bloating they can try to burst these but with sound waves and things like that but most of the time they just go in and remove the gallbladder okay then I'm gonna stop us right here and we'll pick up with the activities of our inside of the digestive system on the next one okay