E9. Liver structure and function Flashcards
Role of the liver?
- Glycogen, iron, & vitamins storage;
- Protein, hormones & cholesterol synthesis;
- Detoxification (including drugs);
- Red blood cell destruction;
- Bile production;
- Metabolism of protein, fats, & carbohydrates.
Describe hepatocytes
Hepatocytes produce most functions of liver;
Describe Kupfer Cells?
Kupfer Cells – Macropahges - removal of viruses, bacteria etc.
Structure of sinusoids?
one note
Describe chronic liver diseases
-Initially, patient still have enough capacity to perform functions of liver, ‘compensated’ liver disease;
-Advanced stages, capacity of liver is insufficient. Normal function, metabolism is affected, ‘decompensated’ liver disease.
Describe hepatitis liver disease
Inflammation of liver;
Caused by:
Alcohol;
Viruses e.g., hepatitis A, B C.
Describe alcoholic liver disease
Alcoholic Fatty Liver Disease:
-Build-up of fatty acids in liver;
-Reversible.
Alcoholic Hepatitis:
-Second stage of liver damage;
-Prolonged alcohol misuse.
Cirrhosis:
-Final stage & irreversible;
-Scarring and loss of function.
Describe non-alcoholic liver disease
-Build-up of fatty acids in liver due to high BMI;
-Can lead to steatohepatitis;
-Eventually cirrhosis.
Describe liver cancer
-Similar symptoms to above;
-Can be result of damage caused by cirrhosis;
-1 in 3 cases due to alcohol misuse;
-Smoking enhances risk of cancer with hepatitis B & C.
Liver damage can be caused by drugs or environmental factors such as?
Damage can be caused by drug itself;
E.g., ciglitazone, ketoconazole;
Or due to toxic metabolite;
E.g., paracetamol.
what can cause liver drug toxicity?
one note
Describe paracetamol effects on liver
-Paracetamol is non-toxic at normal doses;
-Overdose can cause hepatotoxicity & death.
ONE NOTE FOR METABOLISM OF PARACETAMOL PATHWAY
Symptoms of cirrhosis?
-Pain around liver;
-Jaundice, yellow skin and whites of eyes (build-up of bilirubin);
-Very itchy skin or pruritis (build-up of bile salts);
-Tiredness;
-Nausea;
-Oedema in legs and ankles;
-Ascites (build-up of fluid in abdomen).
Diagnosis of cirrhosis?
Altered liver enzymes, liver function tests
what is cholestasis and what is it caused by?
-Impaired flow of bile to duodenum
Caused by:
-Blockage of bile duct, e.g., gallstones or cancer;
-Disturbances in bile formation e.g., cirrhosis.
Enterohepatic Recycling of Bile?
one note
Describe gallstones
-Small stones in gall bladder;
-Often due to excess cholesterol in bile;
-Can lead to block of bile ducts leading to intense pain.
Describe pruritus
-Reduce bile acids with colestyramine (binds to bile acids);
-Histamine Receptor Antagonists;
-Menthol in aqueous cream (cooling effect).
what is hepatic encephalopathy and what is it characterised by?
-Major neuropsychiatric complication of cirrhosis;
Characterized by:
-Confusion, drowsiness, disorientation;
-Personality changes;
What is Hepatic Encephalopathy caused by?
Accumulation of toxins e.g., ammonia not cleared by the liver
Treatment for Hepatic Encephalopathy?
-Reduce plasma ammonia;
-Lactulose (disaccharide laxative) inhibit the growth of ammonia-producing organisms;
-Neomycin & rifaximin (antibiotics) reduce urease-producing colonic bacteria.
What is Wernicke’s Encephalopathy?
-Acute confusion, psychosis, ataxia and oculomotor dysfunction;
-Occurs due to lack of thiamine (vitamin B1) and often associated with high
alcohol intake;
-Reduced intake and absorption;
-High doses of thiamine used to treat/prevent.
what is Ascites?
-Accumulation of fluid in the peritoneal cavity;
-Due to lack of albumin;
-Causing reduced oncotic pressure and oedema;
therapy for Ascites?
-Reduce sodium intake;
-Fluid restriction.
-Diuretics e.g., aldosterone receptor antagonist (spironolactone);
-Diuretics e.g., furosemide;
-Drain fluid (paracentesis).
Treatment of alcoholism?
-Disulfiram, Acetaldehyde Dehydrogenase Inhibitor
-Reaction comes on 5 min. after taking alcohol.
-Generalized vasodilatation, fall in blood pressure, sweating,
dyspnoea, headache, chest pain, nausea and vomiting.
ONE NOTE
