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
Mechanisms of liver injury in viral hepatitis
. Direct cellular injury
. Induction of immune responses against the viral antigens
Alcohol induced liver disease
. Fatty liver disease
. Alcoholic hepatitis
. Cirrhosis
. Mechanisms
. ADH
. MEOS
. Peroxisomes
Causes of intrahepatic biliary disease
. Primary biliary cirrhosis
. Primary sclerosis cholangitis
. Secondary biliary cirrhosis
Symptoms of intrahepatic biliary disease
. Early symptoms
- unexpected puritus or itching
- weight loss
- fatigue
. Later symptoms
- dark urine and pale stools
- jaundice
Cirrhosis
. Fibrosis replacement of hepatic tissue
. Loss of liver function
Manifestations of cirrhosis
. Weight loss . Weakness . Anorexia . Diarrhea or constipation . Hepatomegaly . Jaundice . Abdominal pain . Portal hypertension . Ascites . Esophageal varies . Splenomegaly
Manifestations of liver failure
. Hematologic disorders
. Endocrine disorders
. Skin disorders
. Hepatorenal syndrome
. Hepatic encephalopathy
Portal hypertension
. Portal hypertension
- acites
- esophageal varices
- splenomegaly
Treatment for liver failure
. Eliminating alcohol intake when the condition is caused by alcoholic cirrhosis
. Preventing infections
. Providing sufficient carbohydrates and calories to prevent protein breakdown
. Correcting fluid and electrolyte imbalances
. Decreasing ammonia production in the gastrointestinal tract by controlling protein intake
. Liver transplantation
Types of primary liver cancer
. Hepatocellular carving
- arises from the liver cells
. Cholangiocarcinoma
- a primary cancer of bile duct cells
Gallbladder
. Definition: a distensible, peer shaped, muscular sac located on the ventral surface of the liver
. Layers
- outer serous peritoneal layer
- Middle smooth muscle layer
- inner mucosal layer that is continuous with the linings of the bile ducts
. Functions : stored and concentrate bile
Components of the hepatobiliary system
. Gallbladder
. Left and right hepatic ducts
- come together to form the common hepatic duct
. Cystic duct
- extends to the gallbladder
. The common bile duct
- formed by the union of the common hepatic duct and cystic duct
Gallbladder and formation of gallstones
. Entrance of food into the intestine causes the gallbladder to contract and the sphincter of the bile duct to relax, such that bile stored in the gall bladder moves into the duodenum
. Two primary factors contribute to the formation of gallstones: abnormalities in the composition of bile and the stasis of bile
. The formation of cholesterol stones is associated with obesity
Common disorders of the biliary system
. Cholelithiasis
- Choledocholithiasis
. Inflammation of the gallbladder ( cholecysititis)
. Inflammation of the common bile duct ( cholangitis)
Pancreatic secretions
. Contain proteolytic enzymes that break down dietary proteins
. Secretions include pancreatic amylase
- breaks down starch, and lipase which hydrolyze neutral fats into glycerol and fatty acids
. The pancreatic enzymes are secreted in the inactive form and become activated in the intestine
Common causes of Acute Pancreatitis
. Gallstones . Alcohol abuse . Hyperlipidemia Hyperparathyroidism . Infections . Abdominal and surgical trauma . Drugs such as steroids and thiazides diuretics
Forms of Chronic Pancreatitis
. Chronic calcifying pancreatitis
. Chronic obstructive pancreatitis
Causes of pancreatic cancer
. The cause of pancreatic cancer is unknown
. Smoking appears to be a major risk factor
. The second most important factor appears to be diet
- increasing total calorie intake
- high intake of fat, meat, salt , dehydrated foods, fried food, refined sugar, soy beans, and nitrosamines
