Liver Function

Flashcards for vocabulary related to liver function and liver diseases.

Liver

Chief metabolic organ; detoxifies blood; divided into two lobes by the falciform ligament.

Gallbladder

Site of bile storage; connected to the common bile duct.

Hepatic artery

Supplies the liver with approximately 25% of blood/minute, oxygenated.

Portal vein

Supplies the liver with approximately 75% of blood/minute, nutrients.

Hepatocytes

Liver cells important for metabolism, synthesis, and production of metabolic substances (proteins).

Kupffer cells

Macrophages in the liver important for phagocytosis.

Glycogenesis

Formation of glycogen from glucose.

Glycogenolysis

Breakdown of glycogen to glucose.

Gluconeogenesis

Synthesis of glucose from non-carbohydrate substances (fats and proteins).

Transamination

Formation of ketoacid and ammonia during detoxification in the liver.

Bile

Dark green or yellowish-brown fluid produced by the liver, stored in the gallbladder, released into the duodenum, and helps in lipid digestion.

Bile acids

Unconjugated form; products of cholesterol metabolism and the primary components of the bile.

Bile salts

Conjugated form; conjugated with amino acids.

Primary bile acids/salts

Cholic acid and Chenodeoxycholic acid; bile acids/salts not yet exposed to the normal flora of the intestine.

Secondary bile acids/salts

Deoxycholic acid, Lithocholic acid, and Ursodeoxycholic acid; exposed to the normal flora of the intestine.

Biliverdin

Pigment that imparts the greenish color to the bile.

Bilirubin

Pigment that imparts yellow color to the bile; metabolic waste product of heme breakdown.

Ligandin

Brings B1 (unconjugated bilirubin) to its destination (smooth endoplasmic reticulum of the liver cells)

UDPGT

Enzyme responsible for the conversion of B1 (unconjugated bilirubin) to B2 (conjugated bilirubin).

Urobilinogen

Colorless substance formed in the intestines by the action of bacteria on bilirubin.

Urobilin/stercobilin

Yellow/brown pigments in the stool formed when urobilinogen is oxidized.

Alpha-bilirubin (B1)

Unconjugated bilirubin

Gamma-bilirubin (B2)

Diglucuronide bilirubin

Delta bilirubin

Conjugated bilirubin that is irreversibly bound to albumin (Biliprotein)

Jaundice/Hyperbilirubinemia

Elevated bilirubin in the blood; yellow discoloration of the skin and sclera of the eyes.

Kernicterus

Neurological damage in infants caused by bilirubin passing the blood-brain barrier (>20 mg/dL).

Pre-hepatic jaundice

Main problem is in the blood; hemolysis/hemolytic disease; elevated B1.

Hepatic jaundice

Main problem is the liver; intrinsic defect; diseases resulting in hepatocellular injury or destruction.

Post-hepatic jaundice

Main problem is bilirubin excretion; biliary obstruction; elevated B2.

Physiologic Jaundice of the newborn

Immaturity of the liver – Deficient UDPGT and affects the conjugation function of the liver;Elevated B1

Crigler-Najjar Syndrome

Gene mutation that is responsible for the production of UDGPT; UGT1A1 gene: defective; Elevated B1 and decreased B2

Gilbert Syndrome

Characterized by impaired cellular uptake of bilirubin; Defect in bilirubin transport; also, some benign deficiency of UDGPT; Elevated B1 because of transport defect

Lucey-Driscoll Syndrome

Circulating inhibitor of bilirubin conjugation; Familial form of unconjugated hyperbilirubinemia (inherited genetic disorder); Elevated B1 because the conjugation of bilirubin is affected due to circulating inhibitors

Dubin-Johnson Syndrome

Genetic defect; MDR2/cMOAT Deficiency (Canalicular Multi-Specific Organic Anion Transporter); Elevated B2; Normal B1; Deposition of lipofuscin in the liver

Rotor Syndrome

Genetic defect; Defect in bilirubin excretion; Elevated B2; Unknown etiology; No dark pigmentation of the liver

Cirrhosis

Occurs secondary to chronic hepatocellular damage; Conjugation and excretion function of the liver is affected since there is tissue scarring; B1 and B2: elevated

Hepatitis

Inflammation of the liver

Biliary Obstruction

Cause of post-hepatic jaundice; Caused by gallstones, Cholelithiasis, Pancreatic Tumor; Elevated B2

Reye’s Syndrome

Non-inflammatory encephalopathy; Affects the neurologic functions of the brain; Fatty degeneration of the liver; Threefold increase of ammonia in the blood

Alcoholic fatty liver

Initial phase; Slight elevated in AST, ALT and GGT; On biopsy, fatty infiltrates are noted in the vacuoles of the liver.

Alcoholic hepatitis

Presents with common signs and symptoms: fever, ascites, proximal damaged; Moderately elevated AST, ALT, GGT, alkaline phosphatase (ALP) and elevated in total bilirubin

Alcoholic cirrhosis

Most severe; common in males than females; Increased liver function tests (AST, ALT, GGT, ALP and total bilirubin); Decreased albumin and prolonged prothrombin time.

AST and ALT

↑ in Liver Enzymes indicates damaged or necrotic hepatocytes; Drug hepatotoxicity

Lactate dehydrogenase (LD)

↑ in Liver Enzymes indicates acute Hepatitis and Cirrhosis

Ammonia

converted to urea d; elevated levels indicate problems with detoxification in the liver

MELD Score

Determine prognosis and probability of survival of patients with liver disease. Higher Score = lower prognosis, lower probability of survival.

PGA Index

Purpose: Differentiate Alcoholic cirrhosis from Alcoholic hepatitis

Autoimmune Markers

Used to diagnose liver disease

Van den Berg Reaction (Diazotization)

Chemical method for Serum Bilirubin determination

Bilirubin Oxidase

Enzymatic method for Serum Bilirubin determination

Icterus Index

Estimate presence of hyperbilirubinemia; Standard solution used is 0.01% Potassium dichromate

Direct Spectrophotometry

Exclusive for Neonates and newborn only, no reagents are used, uses 455 nm wavelength

Evelyn-Malloy Method

Van den Berg Reaction (Diazotization)

Jendrassik-Grof Method

Van den Berg Reaction (Diazotization)