Liver Disease
Let’s Review the Liver!
Anatomy
•Largest internal organ in the body
•Divided into right and left lobes (right is largest and is further divided into caudate and quadrate lobes)
•Within the lobes are smaller units called lobules which consist of hepatocytes (liver cells)
•The hepatocytes are the functional cells of the liver, the remaining mass is made up of Kupffer cells, stellate cells,
endothelial cells, blood vessels, bile duct cells and supporting structures.
Hepatic Blood Supply
•Obtains dual blood supply from the portal vein and hepatic artery...this is very unique! A vein is located between
two capillary beds. The hepatic vein collects blood from capillaries in visceral structures located in the abdomen
and empties it into the liver.
•The liver gets approximately 1500 ml of blood/minute. This comes out to 13% of total body blood supply. The
hepatic artery supplies 25% (around 300 ml/min), and the portal vein supplies 75% (around 1050 ml./min).
Because the portal vein supplies most of the blood supply, you can imagine why it’s so devastating when that vein
gets backed up...lots and lots of blood with no where to go (except back into the portal system).
•The hepatic vein empties into the inferior vena cava
•The liver stores 450 ml of blood due to pressure differences between the hepatic vein and the vena cava.
•In CHF, blood backs up and accumulates in the liver. That can’t be good!
•Hepatic portal vein takes all the flow from other vessels....it there are problems it’s going to back up to all these
other organs. (see slide, it’s the blue veins)
•Our biggest concern is with cirrhosis or fatty liver, and we can’t get blood flow to go back out through the hepatic
vein and on through the system.
Digestive Role
•Produces bile (main fxn). Bile emulsifies fats and stimulates peristalsis (more on bile below)
•Conveys bile from the gallbladder (where bile is stored) until it enters the duodenum at the Sphincter of Oddi
through the common bile duct
•Processes and stores fats, carbohydrates and proteins
•Processes and stores vitamins and minerals (fat-soluble vitamins A,D,E,K, B12, copper and iron...iron is in the
form of ferritin). Vit A is necessary for retinal fxn and epithelial cellular growth; Vit B-12 is necessary for DNA
synthesis, normal RBCs and nerve fxn (Pernicious anemia is d/t a lack of Vit B-12); Vit K is necessary for clotting.
•Synthesizes cholesterol
•Produces triglycerides
What is bile?
Bile is an alkaline fluid composed of cholesterol, phospholipids, bile salts, bile pigments (bilirubin), proteins and
electrolytes. The liver produces 600-1200 ml of bile a day 97% of which is water). It flows through the canaliculi, into the
common bile duct, goes through the Sphinctor of Oddi and empties into
the duodenum. Bile is stored in the gallbladder, where it is concentrated,
and discharged into the duodenum when fatty chyme enters from the
stomach. The function of bile is to emulsify fats, facilitating their digestion
in the small intestine by pancreatic lipase. It is also necessary for
transport of cholesterol via fatty acids and the transport of fat soluble
vitamins (ADEK). Bile also stimulates peristalsis. 94% of the bile salts
that go into the intestines is reabsorpbed into the portal circulation for
recycling.
Metabolism Role (carbohydrates, fats and proteins)
•Carbohydrates
•production of glucose from proteins and fats
Liver pg 1 of 12
Terms To Know
Glycogenesis = formation of glycogen from glucose
Lipogenesis = formation of fat from CHO
Glycogenolysis = breaking down of glycogen
Gluconeogenesis = AA + glycerol + lactic acid = glucose
