Liver Flashcards
Importance of the liver
Metabolism: The liver is responsible for metabolizing carbohydrates, fats, and proteins. It converts glucose into glycogen for storage and releases it when the body needs energy. It also breaks down fats into fatty acids and glycerol, which are used for energy production.
Detoxification: The liver detoxifies the body by breaking down harmful substances, including drugs, alcohol, and environmental toxins. It converts these substances into less harmful compounds that can be eliminated from the body.
Storage: The liver stores nutrients, such as vitamins and minerals, and releases them into the bloodstream when needed. It also stores glucose as glycogen and releases it when the body requires energy.
Bile production: The liver produces bile, which helps digest fats in the small intestine. Bile also helps eliminate waste products, including bilirubin, from the body.
Immune system function: The liver plays a crucial role in the body’s immune system by removing bacteria and other foreign particles from the bloodstream.
Classification of liver disease
Viral hepatitis: This is an infection of the liver caused by one of several viruses, including hepatitis A, B, C, D, and E. Viral hepatitis can cause inflammation and damage to the liver, which can lead to liver dysfunction. In severe cases, it can lead to liver failure or cirrhosis.
Alcoholic liver disease: This is a condition that occurs when the liver is damaged by excessive alcohol consumption over a period of years. Alcohol can cause inflammation and scarring of the liver, leading to liver dysfunction. In severe cases, it can lead to cirrhosis or liver failure.
Non-alcoholic fatty liver disease (NAFLD): This is a condition that occurs when the liver accumulates excess fat, not due to excessive alcohol consumption. NAFLD is often associated with obesity, high blood pressure, and insulin resistance. In some cases, it can progress to non-alcoholic steatohepatitis (NASH), which is a more severe form of liver dysfunction.
Cirrhosis: This is a condition in which the liver is scarred and damaged, leading to liver dysfunction. Cirrhosis can be caused by a variety of factors, including chronic viral hepatitis, alcohol consumption, NAFLD, and autoimmune disorders. In severe cases, it can lead to liver failure.
Autoimmune liver diseases: These are conditions in which the body’s immune system attacks the liver, causing inflammation and damage. Examples include autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. Autoimmune liver diseases can lead to liver dysfunction and cirrhosis.
Liver cancer: This is a type of cancer that begins in the liver. Liver cancer can be primary (originating in the liver) or secondary (spreading to the liver from another part of the body). Liver cancer can cause liver dysfunction and can be life-threatening if not treated promptly.
To understand and interpret the commonly used
liver function tests (LFTs)
Alanine transaminase (ALT): ALT is an enzyme that is mainly found in the liver. When liver cells are damaged, ALT is released into the bloodstream, causing its levels to increase. Elevated ALT levels can indicate liver damage or injury, such as in cases of viral hepatitis, alcohol-related liver disease, or non-alcoholic fatty liver disease.
Aspartate transaminase (AST): Like ALT, AST is an enzyme that is predominantly found in the liver. AST levels also increase when liver cells are damaged or inflamed, but AST can also be released by other organs, such as the heart or muscles. Elevated AST levels can indicate liver damage, but can also be caused by other conditions, such as heart disease, skeletal muscle injury, or pancreatitis.
Alkaline phosphatase (ALP): ALP is an enzyme that is produced by cells in the liver, bile ducts, and bones. Elevated ALP levels can indicate a blockage in the bile ducts, such as in cases of gallstones or liver tumors, or bone disorders, such as Paget’s disease or osteomalacia.
Total bilirubin: Bilirubin is a yellowish pigment that is produced by the breakdown of red blood cells in the liver. Elevated levels of bilirubin in the blood can indicate liver damage or disease, such as in cases of viral hepatitis, alcoholic liver disease, or cirrhosis.
Albumin: Albumin is a protein that is produced by the liver. Low levels of albumin in the blood can indicate liver damage or disease, as well as other conditions, such as malnutrition or kidney disease.
Prothrombin time (PT): PT is a measure of how long it takes for blood to clot. The liver produces many of the proteins involved in the clotting process, so PT can be used as an indicator of liver function. Prolonged PT can indicate liver damage or disease, as well as other conditions, such as vitamin K deficiency or certain medications.
To learn the clinical signs and symptoms of liver
disease and their treatments
Some of the common signs and symptoms of liver disease include:
Jaundice - yellowing of the skin and whites of the eyes
Fatigue and weakness
Nausea and vomiting
Loss of appetite
Abdominal swelling and pain
Dark urine
Pale stools
Itchy skin
Mental confusion
Easy bruising and bleeding
ome common treatments include:
Antiviral medications: These medications are used to treat viral hepatitis, such as hepatitis B and C. Examples include interferon, ribavirin, and direct-acting antiviral agents like sofosbuvir, ledipasvir, and daclatasvir.
Corticosteroids: These medications are used to reduce inflammation in the liver and are often prescribed for autoimmune hepatitis. Examples include prednisone and budesonide.
Ursodeoxycholic acid: This medication is used to treat primary biliary cholangitis, a type of liver disease that causes damage to the bile ducts. Ursodeoxycholic acid helps to reduce liver damage and improve liver function.
N-acetylcysteine (NAC): This medication is used to treat acetaminophen (paracetamol) overdose, which can cause liver damage. NAC helps to prevent liver damage by increasing levels of glutathione, a natural antioxidant in the liver.
Lifestyle changes, such as reducing alcohol intake and maintaining a healthy weight.
Nutritional support to help manage symptoms and maintain liver health.
Liver transplant surgery in severe cases where the liver is no longer functioning properly.
To understand the main causes of liver disease
Viral hepatitis: Hepatitis A, B, and C are viral infections that can cause inflammation and damage to the liver. Hepatitis B and C are the most common causes of chronic liver disease and can lead to cirrhosis and liver cancer.
Alcohol abuse: Drinking excessive amounts of alcohol over a long period of time can cause inflammation and damage to the liver. This can lead to fatty liver disease, alcoholic hepatitis, and cirrhosis.
Non-alcoholic fatty liver disease (NAFLD): This is a condition where fat accumulates in the liver, causing inflammation and damage. It’s often associated with obesity, insulin resistance, and metabolic syndrome.
Autoimmune hepatitis: This is a condition where the body’s immune system attacks the liver, causing inflammation and damage.
Genetic diseases: Some genetic diseases can cause liver disease, such as hemochromatosis, Wilson’s disease, and alpha-1 antitrypsin deficiency.
Medications and toxins: Certain medications and toxins can cause liver damage, such as acetaminophen (paracetamol) overdose, certain antibiotics, and exposure to certain chemicals.
Bile duct diseases: Diseases that affect the bile ducts, such as primary biliary cholangitis and primary sclerosing cholangitis, can cause inflammation and damage to the liver.
Highlight the pharmacokinetic changes that may occur when administering drugs to patients with hepatic disease.
Absorption: The absorption of drugs may be affected by changes in liver blood flow, as well as alterations in the gastrointestinal tract associated with liver disease. For example, increased gastric pH, delayed gastric emptying, and decreased intestinal motility can all affect drug absorption.
Distribution: Changes in the protein-binding capacity of the liver, as well as alterations in blood flow and tissue perfusion, can affect drug distribution. In patients with hepatic disease, drugs that are highly protein-bound may accumulate in the bloodstream due to decreased protein binding, leading to increased toxicity.
Metabolism: The liver is the primary site of drug metabolism, and hepatic disease can affect the activity of drug-metabolizing enzymes such as cytochrome P450 (CYP) enzymes. Changes in CYP activity can result in altered drug metabolism and potentially increased drug toxicity.
Elimination: The liver is also responsible for drug elimination, and hepatic disease can impair the liver’s ability to eliminate drugs from the body. This can result in increased drug exposure and toxicity, as well as a prolonged drug half-life.
