Week 4: Intro to liver physio and diseases

Question 1

hepatic fibrosis and stellate cell activation

Answer 1

• with liver injury, stellate (ito) cells trans differentiate into myofibroblast and lay extracellular collagen
• fibrosis can be reversible

Question 2

Test reflecting metabolic function of the liver

Answer 2

• glucose: gluconeogensis, glycolysis, glycogen storage
• fatty acid oxidation: beta oxidation, ATP formation,
• serum lipids: cholesterol, HDH, LDL, TGs
• urea synthesis: conversion of ammonium to urea. activity loss assoc. with encephalopathy-BUN, ammonium
• Vit A,D, E. Stellate cells store Vit A. Vit D processing in liver (to 25-OH VitD), Vit E is retained and packaged in liver.

Question 3

Test reflecting synthetic function of the liver

Answer 3

Predominant site for synthesis of serum proteins
-clothing factors: I, II, V, VII, VIII, IX, X, protein C, S, and X
-albumin
-a-1 antitrypsin
-cerruloplasmin: reduced in wilson’s dx.
-

Question 4

Test reflecting excretory function of the liver

Answer 4

• bilirubin
• cholesterol, phospholipids
• bile salts

Question 5

General clinical presentation for liver disease

Answer 5

-asymptomatic
-fatigue, weakness, jaundice
-pruritus-associated with bile salts
-neuropsych: hepatic encephalopathy, sleep disorder
Findings
-liver size, spleen may increase in size from portal HTN, ascites, mass, bruit over liver, jaundice

Question 6

Markers of hepatocellular injury

Answer 6

• high AST and ALT (aspartate aminotransferase and alanine aminotransferase), and LDH (nonspecific)
• ALT is liver predom. but also in kidney and heart.
• AST also present in skeletal muscle, heart. Isolated elevation may be other organ.
• Obese can present with abn. liver tests
• AST: ALT ratio, 2:1 in alcoholic hepatitis.

Question 7

cholestatic liver disease-causes

Answer 7

Excretory function of liver is impaired

1. liver
   - genetic, canalicular dysfunction, drugs
2. bile ducts
   - cholangiocytes: primary biliary cirrhosis, sclerosing cholangitis
   - stricture, gallstones, injury
3. Pancreas
   - pancreatic cancer, ampullarf tumor
   - metastatic disease

Question 8

Markers of cholestatic injury

Answer 8

-Alk phos
-GGTP can confirm, gamma glutamyl transpeptidase
IMPAIRED secretion
-elevated bilirubin- direct
-elevated cholesterol
-elevated bile salts
-evidence of fat malabsorption