Liver Flashcards
List the main causes of cirrhosis
Chronic:
- Chronic Alcohol Consumption
- Non-Alcoholic Fatty Liver Disease (some people have a strong genetic predisposition)
- Autoimmune disease
- Genetic Disease
- Hepatitis B and C
- Obstruction (gall stones, tumour)
- Congestive Heart Disease
- Secondary metastatic cancer
Three characteristics of cirrhosis
- Continued cell injury, death and attempt at repair
- Parenchymal modules separated by fibrous septae
- Diffuse architectual disruption
Cirrhosis
Chronic inflammation
Progressive fibrosis
Continued proliferation of hepatocytes
- contraction occurs in areas of maturing granulation tissue - architecture has been distructed - lobule has lose hexagonal structure and differing oxygen tensions - function is decreased - can result in liver failure
Explain the potentially life-threatening conditions that cirrhosis can cause even before it has led to complete failure of the liver
HCC
- normally a primary cancer of the liver is rare
- cirrhosis and chronic inflammation can result in numerous primary cancers due to high rate of proliferation
Consequences of portal hypertension
- venous system is low pressure, therefore congestion will result in dilation of the veins
- congested veins could rupture and cause major bleed (if liver fails, clotting factors are no longer made and will result in impaired coagulation)
- oesophageal veins are most prone (veins may bulge into lumen of oesophagus or external surface)
Liver failure
Complications of Portal Hypertension
Ascites
Splenomegaly
Anastamoses between portal and systemic circulation
Congestion in portal circuit relationship to ascites
Ascites is common and and there is an increased risk of oedema
- increased hydrostatic pressure - increase fluid leakage due to the congestion of veins
liver fails - stop making plasma proteins - colloidal pressure decreases - very bad oedema
Pathogenesis of Ascites
Portal hypertension - congestion in portal venous system - increased hydrostatic pressure
liver failure - Reduced production of plasma protein including albumin - hypoalbuminemia - reduced colloidal pressure of the plasma
Together cause oedema and ascites
Systemic Complications of Liver Failure
Cannot break down ammonia. It can then build up in blood and potentially cross the blood brain barrier to cause a coma
Weight loss
Liver is no longer metabolising
Disruption in some of the hormonal pathways - liver makes cholesterol can metabolises other hormone (no longer occurs)
Can affect levels of androgens, testosterone and estrogen. Can result in excessive estrogen in males.
Elevated serum billirubin (jaundice)
Reduced transport of hormones
Malabsorption of fat and fat soluble vitamins
Increase waste in blood
Cells of the pancreas
Langahan - endocrine portion creating hormones entering vessels to have an effect at different sites
Islet cells - make digestive enzymes and bicarbonate (neutralise chyme and bicarbonate)
Acute Pancreatitis
Injury to pancreas - pancreatic cells die - release digestive enzyme in pancreas - can result in autodigestion or enzymatic fat digestion
Chronic Pancreatitis - clinical features
Insidious onset (gradual or subtle, but very harmful)
Pain in upper abdomen that radiates into the back
Atrophy
Malabsorption caused by pancreatic insufficiency
Pancreatic Neoplasms
In 95% of all cases, tumours are:
- malignant rather than benign
- functionally silent rather than hormonally active
- solid rather than cystic
- exocrine rather than endocrine
- derived from ducts rather that acini or islets
Carcinoma of the pancreas - Clinical Features
Weight loss, loss of appetite, nausea
jaundice if located in head
courvoisiers sign (gallbladder distention)
pain
metastases
Functional Units of Liver
Liver makes bile - bile flows into bile tracts and enters the bile ducts
Portal veins draining from spleen, pancreas and all venous drainage of GI tract. Arterial blood arrives from hepatic artery. Blood mixes together and drains towards central vein
Functional zones are separated into zones (each are exposed to different stressors
Cholestasis
Static bile
