Liver Anatomy and Physiology

Located in the upper-right quadrant of the abdomen.

The liver receives blood from the hepatic artery and portal vein.

The liver performs over 500 tasks crucial for life, including metabolism, vitamin/mineral storage, and detoxification.

Bile, produced by the liver, aids in fat digestion and absorption.

The liver converts other sugars to glucose, stores glucose as glycogen, and breaks glycogen down to glucose when needed.

Approximately 1500mL of blood circulates through the liver per minute.

The liver has four anatomical lobes: right, quadrate, caudate, and left. Two functional lobes are right and left.

The liver is involved in the metabolism of drugs and alcohol, filtering them from the blood.

Transfer of an amino group from one molecule to another.

Removal of an amino group from a molecule.

Breaking down fatty acids into energy (acetyl-CoA).

Energy source formed from fat breakdown.

Liver stores fat-soluble vitamins, B12, and minerals

Liver synthesizes proteins to carry vitamins and minerals.

Tests checking liver's health, including bilirubin levels in blood and urine.

Measure of bilirubin in blood; high levels may indicate liver problems.

Increased levels of bilirubin in the blood, often a sign of liver or bile duct problems.

Bilirubin produced from broken-down red blood cells.

Bilirubin that the liver has processed and is ready for excretion.

An enzyme primarily found in the liver, elevated levels indicate liver damage.

An enzyme found in the liver, heart, and muscles. Elevated levels, along with ALT, indicate liver damage.

Indicates potential conditions such as alcoholic liver disease, liver congestion, or tumors.

Suggests acute hepatitis or viral liver infection.

Inflammation of the liver tissue caused by viruses, bacteria, toxins, obstructions, parasites, or chemicals.

Hepatitis lasting for the first 6 months.

Acute hepatitis generally does not cause permanent damage.

Prothrombin Time, a blood test that measures the time it takes for blood to clot, and a marker of liver dysfunction as decreased clotting factors.

Lower levels indicate liver dysfunction, as decreased synthesis occurs.

Jaundice, dark urine, anorexia, fatigue, nausea, vomiting, fever, enlarged liver (hepatomegaly), and enlarged spleen (splenomegaly).

Elevated ammonia levels indicate increasing liver dysfunction, as the liver struggles to convert it to urea.

Caused by viruses, bacteria, toxins, obstructions, parasites, and chemicals.

A viral infection of the liver transmitted through contaminated food or water, typically resolving without long-term health issues.

Viral infections of the liver transmitted through blood and body fluids. Often leads to chronic conditions, potentially causing cirrhosis and liver failure.

A rare viral hepatitis requiring HBV for replication; a co-infection or super-infection with HBV.

A viral hepatitis transmitted by the fecal-oral route, mostly causing acute infection and uncommon in the US.

A group of viral infections of the liver, often causing inflammation, including HAV, HBV, HCV, HDV, and HEV.

Ongoing inflammation of the liver, potentially resulting in cirrhosis and liver failure.

A sudden and severe form of liver disease leading to liver failure.

A form of liver disease with a sudden onset, typically caused by infection, toxin exposure or other conditions.

Viral hepatitis is the most common cause of hepatic encephalopathy, accounting for roughly 75% of cases. Other causes include chemical toxicity from substances like acetaminophen and drug reactions.

While outdated practice suggested protein restriction, it's now known that most patients with cirrhosis can tolerate a mixed-protein diet up to 1.5g/kg body weight. Unnecessary restriction can lead to malnutrition.

In stable cirrhosis, fluid restrictions are not typically necessary.

In non-stable cirrhosis, where ascites or edema are difficult to manage, a modest fluid restriction may be necessary. The primary goal is to achieve a mildly negative fluid balance.

Hyponatremia, a low serum sodium level, requires fluid restriction. The amount depends on the severity. A sodium level below 128 mEq/L calls for 1200-1500mL per day, while a level below 125 mEq/L requires 1000-1200mL per day.

Multivitamin supplementation is often recommended, prioritizing water-soluble forms for fat-soluble vitamins. A deficiency in thiamine can lead to Wernicke's encephalopathy.

Patients with cirrhosis often benefit from smaller, frequent meals to combat early satiety, which is common with ascites. Prioritizing high-calorie, high-protein foods can optimize nutrient intake.

In cases of steatorrhea (excessive fat in stool), avoiding high-fat foods is crucial. Replacing long-chain triglycerides (LCTs) with medium-chain triglycerides (MCTs) can be beneficial. If stool fat losses are significant, a low-fat diet (40g/d) may be recommended.