what does the liver do (8)
- Digestion
- Liver is responsible for bile salt secretion needed in fat digestion
- Fat (bile breaks it down) and Protein (albumin) metabolism
- Carbohydrate Metabolism
- –>Glycogenesis- glucose is stored as glycogen - Hematologic role
- –>Liver synthesizes fibrinogen, factors I, II, VI, IX, X
- –>Prothrombin is also produced by the liver (with the help of bile and Vit K) - Detoxification
- storage of Vit A, D, B12, iron, copper
- Converts ammonia to urea
bilirubin metabolism pathway (5)
- heme is converted to iron and porphyrin
- porphyrin is converted to biliverdin
- biliverdin is converted to unconjugated bilirubin and travels to the liver
- liver transforms the unconjugated bilirubin to conjugated bilirubin.
- conjugated bilirubin (which has become water-soluble) is able to be excreted by the body through bile
(unconjugated CANNOT be excreted through the bile)
what is bilirubin
yellow-colored compound derived from the breakdown of RBCs- particularly from the heme component of hemoglobin
what is hepatitis
inflammation of the liver
what causes hepatitis (5)
- Virus: A, B, C, D, and E
- –> Epstein-Barr virus
- –> coxsackie virus - Drugs
- –> Acetaminophen (Tylenol)
- –>acetylsalicylic acid (aspirin) - Toxins
- –>Kava (herb)
- –>some mushrooms - Excessive alcohol
- Autoimmune
complications of hepatitis (3)
- liver failure
- liver cancer
- cirrhosis
what is cirrhosis
- a chronic progressive, irreversible damage to liver resulting to decreased liver function
- eventually, damage will lead to fibrosis, scarring, nodule formation, impaired blood flow, and bile obstruction
= liver failure
what causes cirrhosis
- caused by hepatitis and all the factors that can cause hepatitis
- chronic alcohol abuse- the most common cause in the US; hepatitis is the most common cause in developing countries
pathway of clinical manifestations of hepatitis/cirrhosis (10)
- hepatic artery and portal vein become constricted
- pressure rises ( portal hypertension)
- veins supplying the liver become engorged (think of a traffic!) and develop varicosities in the esophagus area (esophageal varices)
- nearby organs utilizing the same circulation like spleen, pancreas, and stomach- enlarge as pressure rises
- Bleeding can occur along the over stretched vessels in esophagus
- portal hypertension continues, increasing pressure pushes fluids into the peritoneal cavity & damaged liver can no longer produce albumin (oncotic pressure!)
= ascites - The scarring and bile obstruction leads to bile accumulation to liver -> this causes inflammation and necrosis of tissues -> bile unable to flow to the GI tract, bile enters the bloodstream
= jaundice - bile in blood causes steatorrhea
- bile in sweat causes excessive itching
- kidneys attempt to excrete it = dark-colored urine
what happens to the hormones regulated by the liver during hepatitis?
liver can NOT inactivate hormones = estrogen builds up in both sexes = female characteristics in males and irregular periods in females
what happens when ammonia builds up from hepatitis? s/s (4)
it passes the BBB = hepatic encephalopathy
- confusion
- personality changes
- asterixis: flapping hand tremors
- fetor hepaticus: stinky breath
diagnostics of hepatitis (4)
- Abdominal ultrasound
- MRI or CT scan of the abdomen
- liver enzymes / liver function test
- Serum aminotransferase: sensitive indicator of liver cells injury
what is a Serum aminotransferase testing?
- ALT- increases primarily in liver disorder
- used to monitor hepatitis or cirrhosis - AST- may not be liver-specific
- it can increase if there is damage or death of tissues in heart, liver, skeletal muscle or kidney. - GGT- elevated in alcoholic liver disease and cholecystitis
