jaundice is yellow coloration the sclera the skin and the mucous membranes due to buildup of bilirubin and there are three main categories of jaundice prehepatic hepatic and enterohepatic entero hepatic is also known as post-hepatic pre-hepatic jaundice can be caused by an increase in hemoglobin breakdown because the bilirubin that causes jaundice is derived from the pigment in blood the hemoglobin the hepatic jaundice can come from abnormalities of hemoglobin things that are causing liver cell death viral or autoimmune problems and tumors post-hepatic can be uh it's just going to be things that are blocking the flow of bile and causing it to build up so you could have bought gallstones there can be strictures that narrow or prevent block the ducts it can be parasites varices chronic pancreatitis and also inflammation so as i mentioned the liver gets a double blood supply from both the hepatic artery in the hepatic portal vein the hepatic portal vein is delivering all the nutrient-rich oxygen poor blood from the gi tract the hepatic artery is bringing oxygen rich blood from the heart from the abdominal aorta and all blood is eventually going to leave the liver through the hepatic vein and here you can see a chart that says just that the blood is going to pull together the oxygenated and and deoxygenated nutrient-rich blood pulls together in the sinusoids and then the oxygen is used by the hepatocytes they are going to look at everything that's been absorbed modify things store things detoxify things and then drain it drains into the central vein the hepatic vein the inferior vena cava and then back to the heart this is another diagram just showing that exact same thing how this blood is pulling together here and then flows to the central vein through the sinusoids bile is the ma a major product of the parasites and it's going to be transported by a duct system to the gallbladder in the gallbladder it's concentrated and stored bile comes from a number of different things the it uses the pigment from hemoglobin and its job is to emulsify triglycerides liver also does other things in terms of carbohydrates lipids and protein metabolism and it's a site where we activate vitamin d a liver biopsy go and take a piece of tissue and uh through uh generally a fine needle biopsy and then you can look at the tissue fix it look at it under a microscope and be able to diagnose a number of different disorders from it this shows the position of the gallbladder again it has neck a body and then the hump is the fundus and this is the storage site so here you can see we have the right hepatic duct and the left back duct that drain the right and left lobes this goes to the common hepatic duct the cystic duct comes from the gallbladder and that fuses with this to make the common bile duct and then that is going to drain down here along with secretions from the pancreas into the first part of the duodenum gallstones come because the liver because the gallbladder concentrates bile gallstones can be formed when it crystallizes these are basically cholesterol and they can cause an obstruction to the flow of bile through the gallbladder if they're small enough they can get stuck in the cystic duct or in any part of the tube system after that treatment can be using drugs using sound waves lithotripsy to break the the gallstones down or commonly the gallbladder is just removed you can live without a gallbladder because it doesn't make anything it just stores bile oftentimes when people have the gallbladder removed they take a it takes a little time for their body to adjust to it during which time there they have a hard time eating fats so bile is produced in the liver stored in the gallbladder and then released from the common bile duct along with the secretions from the pancreatic duct the parasympathetic nerve impulses are going to stimulate bile production and then fatty acids and amino acids in the chyme that enters the duodenum stimulate secretion of cck or cholecystokinin when the kind comes into the duodenum it stimulates secretion of secretin into the blood and the cholecystokinin causes contraction in the gallbladder the gallbladder contracts very strongly it has three layers of muscle and people that have gall stones when that muscle contracts it can be extremely painful secretin then is going to enhance the flow of bile from the liver in order to help to digest the fat we make about a quarter bile a day it's yellowish green in color and the ph varies between 7.6 to 8.6 remember that 7 is neutral so both of these values are alkaline or basic it consists of water cholesterol bile salts and vial pigments okay so bile is a bile acid now remember cholesterol has this structure so this is colic acid which is a bile acid and then a salt's added to it in this case there's an amino acid glycine and sodium this makes this more hydrophilic because the job of bile is to emulsify fats and they have to have a hydrophobic part and a hydrophilic part in order to do so the hydrophobic part is going to be able to interact with the fat itself the hydrophilic part is going to make it soluble so when we eat fats they'll go into our gi tract as these big globules these big globules aren't very our body isn't able to digest them very well or absorb them very well so here's a bile salt remember it has side that's hydrophilic another that's hydrophobic the hydrophobic part is going to surround the hydrophobic fat and the hydrophilic is going to point outwards and so it can break up this big fat globule into smaller pieces this is emulsification okay again the fat globule is broken into smaller pieces through emulsification and then this is going to be able to be absorbed into the absorptive cells in the small intestine the monoglycerides and fatty acids then are going to be repackaged into with a protein coat on the outside and released bile surrounding the fat fatty acid droplets is this is called a micelle this once it's repackaged inside of the absorptive cell is called a chylomicron and these chylomicrons enter the lacteal which is a lymphatic capillary lymphatic capillary then carries all this fat in these chylomicrons through through the lymphatic system which is going to fuse with the rest with the circulatory system at the level of the subclavian vein it then goes to the heart and from there the liver so unlike all the other absorbed nutrients that go directly to the liver the fats only go there after they've been to the heart it's important that the bile salts are reabsorbed and so we have the bile salts being produced and we have the bile coming from the gallbladder and this goes into the duodenum it combines with the fats some of it will be lost in the feces but most of it's going to be reabsorbed in the ilium back to the it'll go into the blood and then back to the liver to be used again one of the advantages of eating a diet that is rich in soluble fiber now insoluble fiber helps to make up the bulk of our our um helps to increase the bulk of our feces it helps things move through our gi tract faster it's things that we can't digest but in soluble fiber is found in oats it's found in the pith or the white part of oranges it's found in apples lots of different things have soluble fiber in it and what soluble fiber does is it binds to these bile salts and takes them out in the feces now the advantage to this is then the liver has to make more and it can't recycle it so the liver will use cholesterol that you have to make more bile salts thereby decreasing your blood cholesterol levels so when you see them advertise that cheerios or oatmeal is heart healthy that's why because you're decreasing your overall cholesterol levels by the soluble fiber ridding the body of cholesterol