Lectures 17, 18: Intro to Liver and LFTs Flashcards
Liver functions
Excretion (biliubin, bile acids, drugs), immune function, growth factor, hormone production, hematopoiesis (fetal), synthesizes proteins (albumin, clotting factors), substrate metabolism, storage, metabolizes drugs
Signs of liver failure
Loss of clotting factors –> coagulopathy; impaired bilirubin clearance –> jaundice; impaired glucose mobilization –> hypoglycemia; impaired metabolite clearance/detox –> encephalopathy; altered blood flow regulation –> renal failure
Signs of liver failure (2)
Reduced clearance of bacteria from portal blood –> sepsis; decreased growth factor/albumin –> anemia, edema; altered metabolism of hormones –> feminization; obstruction to blood flow –> portal HTN
The endothelium within the sinusoid of the liver is…
Fenestrated
What two specialized cells are in the sinusoid?
Hepato-stellate cell encircling the microvasculature and the hepatocyte
Liver macrophage specialized cell
Hepatic Kupffer Cell
Bile is secreted through the
Canaliculi system
Liver bloods supply and implications; __________ pressure/___________ capacitance
Dual: 2/3 through portal vein, 1/3 through hepatic artery; low pO2, easy for areas near central vein to become hypoxic AND liver is RARELY infarcted; low pressure and high capacitance
What drains into the portal vein? (3)
Splenic, coronary, mesenteric
Examples of acute injury and significance for transplant
Tylenol, viral infection, idiopathic; may require transplant if severe, but if it resolves, liver will return to normal
Examples of chronic liver injury and significance for transplant
Viral infection, alcohol, obesity-related, autoimmune, metabolic overload, biliary obstruction; chronic liver injury is progressive and may be asymptomatic
Histology of cirrhosis
Nodules surrounded by fibrous tissue
Complications of cirrhosis (5)
Hepatic encephalopathy, ascities, portal HTN, hepatorenal syndrome, splenomegaly
What tests reveal injury to hepatocytes?
AST, ALT bili
What tests reveal injury to bile ducts?
Alkaline phosphatase, gammaGT, bili
Four classes of dx liver tests
Liver enzymes, liver function tests, general systemic tests, liver imaging
Liver enzymes tested
AST, ALT, Alk Phos, Bili
Liver function tests
Albumin, prothrombin time, platelets
General systemic tests
CBC, renal fxn tests (BUN/creatinine)
Signs of chronic liver disease (9)
Scleral icterus, spider angioma, glossitis, palmar erythema, digital clubbing, gynecomastia, excoriations (marks from itching), xanthelasma, ascites