Chapter 38 Disorders Of Hepatobiliary And Excerise Pancreas Function Flashcards
The lobular structure of the liver
. The liver is the largest visceral organ in the body, weighing approximately 1.3kg
. The liver is located below diaphragm and occupies much of the right hypochondrium
. The liver is anatomically divided into two large lobes and smaller lobes
Liver blood flow and accessory organs
. Liver - Hepatic portal veins . Dogestive tract and major abdominal organs - hepatic veins .valveless veins that empty into the inferior vena cava - heptatic artery . Gallbladder . Exocrine pancreas
Functions of the liver and pancreas
. Liver and pancreas
- produce digestive secretions
. Liver
- synthesize glucose, plasma, proteins, blood clotting factors
- carbohydrates, protein, and fat embolism
- is responsible for the degradation and elimination of drugs and hormones
. Endocrine pancreas
- supplies the insulin and glucagon needed in cell metabolism
Functions of the liver
. Production of the bile salts . Elimination of bilirubin . Metabolism of steroids hormones . Metabolism of drugs . Carbohydrates metabolism .Fat metabolism . Protein metabolism .Storage of mineral and vitamins . Filtration of blood and removal of bacteria
Causes of jaundice
. Excessive destruction of red blood cells
. Impaired uptake of bilirubin by the liver cells
. Decreased conjugation of bilirubin
. Obstruction of bile flow in the canaliculi of the hepatic lobules or in the intrahepatic or extrahepatic bile ducts
Categories of jaundice
.prehepatic
- Major causes is excessive hemolysis of red blood cells
. Unconjugated bilirubin
. Intrahepatic
- caused by disorders that directly affect the ability of the liver to remove bilirubin from the blood or conjugate it so it can be eliminated in the bile
. Conjugated bilirubin
. Posthepatic
- occurs when bile flow is obstructed between the liver end the intestine
- conjugated bilirubin
Live Bile
. The liver produces approximately 500 to 600 ml of yellow- green bile daily
. Cholestasis represents a decrease in bile flow through the intrahepatic canaliculi and a reduction in secretion of water, bilirubin, and bile acids by the hepatocytes.
Assessment of liver functions
. Serum aminotransferase levels: assess injury to liver cells
. Serum bilirubin, GGt and Alkaline phosphate: measure hepatic excretory function
. Ultrasonography, CT scans, and MRI : evaluate liver structures
. Angiography: visualizes the hepatic or portal circulation
. Liver biopsy: used to obtain tissue specimens for miscroscopic examination
Pathologic conditions affecting the hepatobiliary system
. Injury from drugs and toxins
. Infection, inflammation and immune responses
. Metabolic disorders
. Neoplasms
Types of reactions involved in hepatic detoxification and metabolism
. Phase 1 reactions
- involve chemical modifications or inactivation of a substance
. Phase 2 reactions
- involve conversion of lipid soluble substances to water- soluble derivatives
. Biotransformations
Host factors contributing to susceptibility to drug- induced liver disease
.Genetic predisposition . Age difference . Underlying chronic liver disease . Diet and alcohol consumption . The use of multiple interacting drugs
Drug induced liver diseases
. Direct hepatotoxic injury
.
. Indiosyncratic reactions
. Cholestatic reactions
. Chronic hepatitis
Causes of Hepatitis
. Autoimmune disorders
. Reactions to drugs and toxins
. Infections disorders
-Malaria, infections mononucleosis
. Hepatotropic viruses that primarily affect liver cells or hepatocytes
- direct cellular injury and induction of immune responses against the viral antigens
Known hepatotropic virus’s
. Hepatitis A virus ( HAV)
. Hepatitis B virus ( HBV)
. Hepatitis b- associated delta virus ( HDV)
. Hepatitis c virus ( HCV)
. Hepatitis E virus ( HEV)
Varying factors of hepatotropic viruses
. Mode of transmission and incubation period
. Mechanisms, degree, and chrroncity of liver damage
. Ability to evolve to a carrier state