Chapter 46 disorders of hepatobiliary and exocrine pancreas function Flashcards
the lobular structure of the liver
- largest visceral organ in the body
- liver is located below the diaphragm
- divided into two large lobes and two smaller lobes
Liver blood flow and accessory organs
+Liver
-hepatic portal vein: drains the blood of digestive tract and major abdominal organs
-hepatic veins within the liver are: valveless vein that empty into the inferior vena cava
- hepatic artery feeds blood to the liver itself
+Gallbladder
+endocrine pancreas
functions of the liver and pancreas
+liver and pancreas= Produce digestive secretions
+liver:
- synthesizes glucose, plasma proteins, and blood clotting factors
-Cars, proteins and fat metabolism
-is responsible for the degradation and elimination of drugs and hormones
+endocrine pancreas
-supplies the insulin and glucagon needed in the cell metabolism
Funtions of the liver
- production of bile salts
- eliminations of bilirubin
- metabolism of steroid hormones
- metabolism of drugs
- cars,fat,protein metabolism
- storage of minerals and vitamins
- filtration of blood and removal of bacteria
cause of jaundice
- excessive destruction of red blood cells “hemolytic jaundice”
- impaired uptake of bilirubin by the liver cells i.e alcoholic damage
- decreased conjugation of bilirubin i.e. infants
- obstruction of bile flow
Categories of jaundice (P.I.P)
+prehepatic
-major cause 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
-conjugates bilirubin
+posthepatic
-occurs when bile flow is obstructed between the liver and the intestine
- cnojugates bilirubin is unable to be secreted in the bowel
liver bile
- the liver produces approximately 500-600 mL of yellow-green bile daily
- cholestasis represents a decrease in bile flow through the intrahepatic canalculi and a reduction in secretion of water, bilirubin, and bile acids by the hepatocytes
assessments of liver function
- serum aminotransferase levels: assess injury to lover cells
- serum bilirubin, GGT, and alkaline phosphatase: measure hepatic excretory function
- ultrasonogrpahy, CT scans, and MRI: evaluate liver structures
- angiography: visualizes the hepatic or portal circulation
- liver biopsy: used to obtain tissue specimen for microscopic examiniation
Pathologic conditions affecting the hepatobiliary system
- injury from drugs and toxins
- infection, inflammation, and immune response
- metabolic disorders
- neoplasms
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
- idiosyncratic reaction
- cholestatic reactions
- chronic hepatitis
causes of hepatitis
- autoimmune disorders
- reactions to drugs and toxins
- infectious disorders
- Malaria, infectious mononucleosis, salmonellosis, and amebiasis
- hepatotropic viruses that primarily affect liver ells or heptocytes
- direct cellular injury and induction of immune responses against the viral antigens
known hepatotropic viruses
-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 hepatototropic viruses
- mode of transmission and incubation period
- mechanism, degree, and chronicity of liver damamge
- ability to evolve to a carrier state
mechanisms of liver injury in viral hepatits
- direct cellular injury
- induction immune responses against the viral antigens
alcohol-induced liver disease
- fatty liver disease (nach)
- alcoholic hepatits
- cirrhosis
causes of intrahepatic biliary disease
- primary biliary cirrhosis
- primary sclerosing cholangtis
- secondary biliary cirrhosis
Symptoms of intrahepatic biliary disease
\+early symptoms -unexplained, pruritus or itching, weight loss, fatigue \+later symptoms -dark urine and pale stools -jaundice
cirrhosis
- fibrosis replacemnet 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 varices, splenomegaly
Manifestaion of liver failure
- hematologic disorders, endocrine disorders, skin disorders, hepatorenal syndrome, hepatic encephalopathy
portal hypertension
+ascites
+esophageal varices
+splenomegaly
treatment of 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 prod, in the GI tract by controlling protein intake
- liver transplantation
types of primary liver cancer
- Hepatocellular carcinoma: arises from the liver cells
- Cholangiocarcinoma: a primary cancer of bile duct cells
Gallbladder
+def: a distensible, pear-shaped, mascular 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 lining of the bile duct
+ function: store and concentrate bile
component of the hepatobiliary system
+gallbladder
+left and right hepatic ducts
- come together to form common hepatic duct
+the cystic duct
- extends to the gall bladder
+the common bile duct
- formed by the union of the common hepatic duct and cystic duct
gallbladder and formation of gallstone
+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 gallbladder moves into the duodenum
+two primary factors contribute to the formation of gallstones: abnormalities in the composition of bile (particularly increase cholesterol) and the stasis of bile.
+the formation of cholesterol stones is associated with obesity
common disorders of the biliary system
- cholelithiasis (gallstones)
- inflammation of the gallbladder (cholecystitis)
- inflammation of the common bile duct (cholangitis)
Pancreatic secretions
- contains enzymes that break down dietary proteins
- secretions include pancreatic amylase
- amylase breaks down starch, and lipases, which hydrolyzes 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
- hyperlidiemia
- hyperparathyroidism
- infections (particularly viral)
- abdominal and surgical trauma
- drugs such as steroid and thiazide diuretics
causes of pancreatic cancer
-the cause: unknown
-smoking appears to be a major risk factor
-the second most important factors appears to be diet
+increasing total calorie intake
+ high intake of fat, meat, salt, dehydrated foods, fried foods, refined sugars, soy beans, and nitrosamines
