hello everyone this is the last video about the digestive system and for this video this is our learning objective in this video we will talk about the accessory digestive organs and will particularly cover liver gallbladder and pancreas the liver is the largest visceral organ we have and most of the liver is located on the right side of our body anatomically the liver has been divided into four lobes anteriorly we can identify the right and left lobes of our liver and we can clearly see that the right lobe is much bigger than the left one what marks the division between the right and left sides of our liver is this ligament called falsi form ligament the falciform ligament is located in the anterior side of the liver and here in the inferior portion of the FAFSA form ligament we see the round ligament the round ligament is formed by the degeneration of the feet umbilical vein now following the fossa formal ligament up we see that it divides into two and these are the right and left coronary ligaments in the liver it holds on to the diaphragm that is right above it through these coronary ligaments when we look at the liver inferiorly so from bottom up we see the other two liver loops and they are named caudate lobe and the quadrate lobe the quadrate lobe looks like a little square and it's found between the left lobe and the goblet now the caudate lobe in reality is caudal because remember we are looking at the liver inferiorly and beside that the caudate lobe looks like a little tail because it's elongated and it's located between the left lobe and the inferior vena cava also if literally we can see the porta hepatis and this is just a deep fissure in the inferior surface of the liver where we find the hepatic portal vein the hepatic artery proper and a common bile duct entering or leaving the liver our liver produces approximately 700 milliliters of bio every day and the function of bio is to emulsify fat present in whatever we ate hence bio needs to be released when we eat because of that we have a little bladder to store bile in the bladder that stores bio is called gall bladder and it is this green sac that we find right below the liver our gall bladder is capable of storing 70 million litres of bio so basically 10% of the total bio volume we produce daily which is 700 milliliters with that being said we can conclude that the gall bladder can get filled to capacity and when there happens the bio composition gradually changes because water is absorbed from the biome and then other components such as bile salts become more and more concentrated because water is being removed and that's the reason why we say that the gall bladder has two main functions one of them is to store bile and the second one is to modify bio because when the gall bladder is filled to capacity water gets removed and then the bio composition changes okay so now we know that liver produces bio and that bio is stored in the Goblet but how does bio leave the liver and goes into the intestine or the gall bladder in case it needs to be stored and the answer is it goes through ducts and you must know the order and what each of these dots connect to so we have the bio that's produced in the right lobe of our liver it leaves the right lobe inside of the right hepatic duct bio that's produced in the left lobe of our liver lives the left lobe in side of the left hepatic duct when the right hepatic duct and the left hepatic duct converge then we have the common hepatic duct now leaving the gallbladder which is the place where bio is stored we have another duct called cystic duct when the cystic duct and the common hepatic duct converge we have another duct that's called bio duct and the bio duct is what connects to the duodenum to the first part of our small intestine and then we have the release of bio in today's mowing testing so the way this works is our liver produces 700 milliliters of bio every day and the bio produced goes down into the common hepatic duct and then it goes into the bio duct here at the end of the bio duct where the bile duct connects to the duodenum we have a sphincter and this is filter just opens when we have time in the duodenum so if we don't have time this is finger is closed and then what happens is that the bio that came down the common hepatic duct and now is down the bio duct and it keeps being produced by the liver it starts to back up back up back up back up and then it starts going into the cystic duct and gets into the gallbladder and that's how bio is stored in the gallbladder when time is released from the stomach into the duodenum that causes anterior endocrine cells present in the duodenum to release a hormone called cholecystokinin CCK the presence of this hormone in the bloodstream inhibit these stomachs muscular contractions and with that prevents from more time to be released into the duodenum and at the same time this hormone stimulates the contraction of the smooth muscle present in the wall of our gall bladder with that our ball bladder start to squeeze bile into the cystic duct then bio goes down into the bile duct and then it is released in the duodenum this is a very clever way that our body has to make sure that bio is released in the duodenum when we actually have kinder the last accessory digestive organ we have to talk about is the pancreas the pancreas is located in the left upper quadrant of our abdomen and it is basically behind the stomach anatomically we subdivide the pancreas into three parts the head the body and the tail the pancreas has an endocrine function as well as an exocrine function and that's important to know because if you have pancreatitis it's not only going to affect digestion but it will also affect endocrine functions the endocrine function comes from the pancreatic islets which make up about 1% of our pancreatic cells and they secrete hormones like insulin and glucagon the exocrine function is the digestive function and this comes from the pancreatic assini also called us in ourselves as tini means grape and these cells are arranged in a grape like structure and they secrete the pancreatic juice into these little ducts and from these little ducts the pancreatic juice moves into the pancreatic duct also called main pancreatic duct the main pancreatic duct runs deep inside the pancreas and it goes from the tail to the head of the pancreas and then it releases the pancreatic juice inside the duodenum approximately 30% of us have a second duct in this duct is small and it is called accessory pancreatic duct this duct just serves as an alternate route to transport pancreatic juice into the duodenum we make 1.2 to 1.5 liters of pancreatic juice every day and in the pancreatic juice we find a lot of water a lot of bicarbonate which is a base and a lot of digestive enzymes enzymes that can digest lipids nucleic acids carbohydrates and proteins so basically in the pancreatic juice we have lipases nucleases carbohydrates and protein lytic enzymes which include proteinases and peptidases we have enzymes that digest everything that our body is made of right because our body is made of lipids carbohydrates proteins and nucleic acids and that's the reason why we secrete pancreatic enzymes we think granules called zymogen grayness because we want to be extra careful when these enzymes are secreted since they could potentially digest the pancreas itself and in fact that one of the problems found in pancreatitis we learn that the liver produces bile and the bio is stored inside the gallbladder we also learned that the pancreas produces pancreatic juice both by your and pancreatic juice are released into the duodenum looking here in the duodenum we see this rounded structure this structure is a sphincter called hepatopancreas eggs filter hip arrow means liver in pancreatic stands for Pingris so this filter controls the release of bile and pancreatic juice into the duodenum what causes this is sphincter to open is the presence of a hormone called colas in stock ining CCK when acidic chyme is released from the stomach into the duodenum that stimulates cells we have within the duodenum to secrete hormones these cells are called enter endocrine cells the presence of acidic chyme we think the duodenum it stimulates these cells to secrete cholecystokinin and secreting hormones cholecystokinin i mentioned before it goes into the bloodstream and it inhibits the muscular contraction in the stomach and at the same time it stimulates the smooth muscle contraction in the gall bladder and with that the gallbladder is squeezes Bayeux out into the cystic duct and then the bio travels through the common bile duct and then it reaches the duodenum at the same time CCK stimulates the pancreas to release the digestive enzymes into the duodenum now I mentioned a second hormone and the second hormone is called secreting secreting is stimulates the release of buffers from the pancreas and that's very important because remember the kind coming from the stomach is acidic so we need the presence of buffers to neutralize this acidic chyme so secreting stimulates the pancreas to release buffers into their duodenum ok so now we know that cholecystokinin CCK he stimulates the release of bio as well as pancreatic juice into the duodenum but what allows these juicy questions to go into the duodenum is the fact that CCK opens up they have Perrow pancreatic sphincter also called is filter of all died when this is filter opens we have the core release the release of bio and pancreatic juice at the same time into the duodenum and with these with finish the digestive system please let me know if you have any questions bye