Liver Flashcards
Anatomic location of liver
RUQ
superior and posterior bounds are diaphragm
lateral- ribs
inferior- GB, stomach, duod, colon, kidney, R adrenal
covered by glisson’s capsule and peritoneum
What defines the R and L lobes of the liver?
the plane formed by the GB fossa and the IVC
What is the falciform ligament?
goes bt liver and diaphragm
landmark bt the lateral and medial segments of the L lobe
What are the coronary ligaments?
They continue laterally from the falciform and end at the R and L triangular ligaments, which define the bare area of the liver (no peritoneum)
How many segments is the liver divided into?
8 parenchymal segments, based on arterial and venous anatomy.
T/F portal circulation gives the liver first access to all venous flow from the intestines.
True
Where does hepatic blood flow come from?
75% from the portal vein (splenic vein joins w SMV)
rest of it is from the hepatic artery, via the celiac axis.
How does blood leave the liver?
via the right, middle, and left hepatic veins to the IVC
What metabolic events occur in the liver?
Glucose is take up and stored as glycogen
Glycogen is broken down to maintain blood glucose leve.
FAs are oxidized to ketones for the brain to use
Proteins are made (coagulation factors, albumin, alpha globulin)
What coagulation proteins are made in the liver?
fibrinogen prothrombin prekallikrein high molecular weight kininogen factors 5, 7, 8, 9, 10, 11, 12
Which coagulation factors are dependent on vitamin K?
prothrombin
factors 7, 9, 10
How does warfarin (coumadin) affect coagulation?
It’s an anticoagulant, and affects the vit-K dependent pathways (prothrombin, 7, 9, 10)
Causes increased prothrombin time.
What are the digestive functions of the liver?
Makes bile
Metabolizes cholesterol
What is used to make bilirubin? How is bilirubin excreted?
Heme is used to make bilirubin
Bilirubin is first conjugated with glycine or taurine and then excreted in bile
What is the fn of bile?
It emulsifies fats so that they can be digested, and helps with vitamin uptake
T/F Bile salts excreted into the intestine are reabsorbed into the portal circulation
True
What is enterohepatic circulation?
The cycle of bile excretion and absorption- bile is excreted from the liver/GB and emulsifies fats, then is reabsorbed back into the liver via the portal circulation (which drains the intestines)
>95% of excreted bile is reabsorbed.
What is the rate-limiting step of cholesterol synthesis?
HMG-coA reductase
acetyl coA –> mevalonate
T/F cholesterol metabolism to bile salts occurs in the GB
False, it occurs in the liver.
What are the two detoxification pathways in the liver?
Phase I (CytP450) reactions- oxidation, reduction, hydrolysis Phase II- conjugation reactions. Imp for toxin clearance.
T/F the first hydroxylation of Vit D occurs in the liver
True
What cells of the liver mediate immunologic fns?
Kupffer cells (liver macrophages)
What are the kinds of benign liver tumors?
Hepatocellular adenoma Focal nodular hyperplasia Hemangioma (most common) Lipoma Only 5% of all liver tumors are benign tho.
What are the types of liver hemangiomas?
Capillary- no clinical consequence
Cavernous- can get to a large size and rupture
Use of what drug increases the risk of adenoma?
Oral contraceptives
HPE of benign liver tumors
If adenoma or hemangioma- can be asx or can px w dull pain.
Rupture - sudden severe pain
If lesions are large, they can be palpated, and they can cause jaundice (dt bile duct obstruction) or sx of gastric outlet obstruction, naus/vom
Focal nodular hyperplasic is usu asx
Dx Eval of benign liver tumors
Usu found incidentally
If there is an adenoma hemorrhage, it can cause hepatocellular necrosis and rise in transaminase levels.
Hemangioma- can cause consumptive coagulopathy.
US- to differentiate cysts from solid lesions
CT- to distinguish bt malignant and benign