Liver Function and Blood Supply Quiz

The liver receives blood from two sources: the hepatic artery (25%) providing oxygenated blood, and the portal vein (75%) carrying nutrient-rich blood from the digestive system.

The liver is composed of three systems: hepatocytes, the biliary system, and the reticuloendothelial system.

Hepatocytes are the main cells of the liver, responsible for a wide range of metabolic activities, including protein synthesis, carbohydrate metabolism, and detoxification.

The biliary system is responsible for the production and secretion of bile, which plays a crucial role in digestion and waste removal.

The reticuloendothelial system, mainly composed of Kupffer cells, plays a key role in immune defense and the breakdown of aged red blood cells.

Liver function tests (LFTs) are a group of blood tests used to assess the health and function of the liver.

LFTs can be used for various purposes, including screening for liver disease, determining the type of liver disease, evaluating the severity and prognosis of liver disease, and monitoring the course of liver disease.

LFTs are not perfect indicators of liver function, as they can be normal in some liver diseases and abnormal in non-liver disorders.

Sensitivity refers to the ability of a test to correctly identify individuals with a specific disease.

Specificity refers to the ability of a test to correctly identify individuals without a specific disease.

Increased serum bilirubin can be caused by various non-hepatic factors, such as hemolysis, ineffective erythropoiesis, and reabsorption of large hematomas.

Increased liver enzyme levels can be caused by factors other than liver disease, including muscle injury, alcohol abuse, and myocardial infarction.

Increased serum alkaline phosphatase levels can be elevated during pregnancy and bone diseases.

Low serum albumin can be due to factors other than liver disease, including poor nutritional status, proteinuria, malabsorption, and severe illness leading to protein catabolism.

LFTs can be categorized into four groups: tests assessing excretory function, tests assessing synthetic and metabolic functions, tests assessing hepatic injury, and tests assessing clearance of exogenous substances.

Bilirubin is a yellow pigment produced from the breakdown of heme, the iron-containing molecule in red blood cells.

Bilirubin metabolism involves several steps, including: uptake by the liver, conjugation with glucuronic acid, secretion into bile, and further processing in the intestines.

Hyperbilirubinemia refers to increased levels of bilirubin in the blood, often leading to jaundice (yellowing of the skin and eyes).

Unconjugated hyperbilirubinemia occurs when bilirubin is not properly conjugated with glucuronic acid.

Prehepatic unconjugated hyperbilirubinemia is caused by increased bilirubin production, usually due to hemolysis.

Hepatic unconjugated hyperbilirubinemia occurs when the liver is unable to effectively uptake, conjugate, and/or secrete bilirubin.

Conjugated hyperbilirubinemia occurs when bilirubin is conjugated but cannot be secreted into bile.

Post-hepatic conjugated hyperbilirubinemia is caused by obstruction of the bile ducts, preventing the flow of bile from the liver.

Neonatal jaundice is a common condition in newborns, often caused by immature liver function and increased bilirubin production.

Physiological jaundice is a temporary and harmless condition in newborns, typically resolving within a few days.

Hemolytic disease of the newborn (HDN) is a serious condition caused by incompatibility between the mother's and baby's blood types, leading to red blood cell destruction.

Breast milk jaundice is a mild and harmless condition caused by substances in breast milk that interfere with bilirubin metabolism.

Biliary atresia is a serious condition where bile ducts are blocked or absent, causing conjugated hyperbilirubinemia.

Idiopathic neonatal hepatitis is a condition with unknown cause, leading to inflammation of the liver and conjugated hyperbilirubinemia.

Gilbert's syndrome is a common inherited disorder affecting the liver's ability to uptake bilirubin, leading to mild unconjugated hyperbilirubinemia.

Crigler-Najjar syndrome is a rare inherited disorder affecting the liver's ability to conjugate bilirubin, leading to severe unconjugated hyperbilirubinemia.

Dubin-Johnson syndrome and Rotor syndrome are rare inherited disorders affecting the liver's ability to secrete bilirubin into bile, leading to conjugated hyperbilirubinemia.