Lecture 11- Liver function and pathology Flashcards
function of the liver
storage
synthetic
metabolic
storage function
- Glycogen
- Vitamins
- Iron
- Copper
synthetic function
- Glucose
- Lipids/cholesterol
- Bile
- Proteins
- Clotting factors
- Albumin
Metabolic function
- Bilirubin
- Ammonia
- Drugs
- Alcohol
- Carbohydrates
- Lipid metabolism
symptoms of luver disease
- jaundice
- oedema/ascites
- bleeding
- confusion
jaundice
- Increase in bilirubin
- Impaired ability of liver to metabolise bilirubin
oedema/ascites
- Albumin- maintain colloid osmotic pressure
- portal hypertension
- Bleeding
Reduced clotting factor production
Confusion
Impaired metabolic function of the liver esp build up of ammonia
Decompensated liver disease-
when there are all four of these symptoms
- jaundice
-oedema/ascites
- bleeding
- confusion
Acute liver disease
sudden onset of these symptoms- no previous history
- Alcohol
- Paracetamol
- Viral
- Medications e.g. aspirin in children
all liver disease leads to
cirrhosis
cirrhosis
Permanent irreversible damage to the liver, impairment of liver function and distortion to the architecture of the liver. In response to chronic inflammation
- Inflammation –> fibrosis and hepatocyte necrosis –> bands of fibrous tissue form which causes nodules to form (think of her balloon analogy)
causes of inflammation in the liver
drugs, infection, depsition disease, autoimmune disorders
drugs which cause inflammation
- can be iatrogenic
- alcohol
alcoholic liver disease
- Most common cause of chronic liver disease
changes causes by excessive alcohol intake
- Fatty change –> excessive amount of sugar converted to triglycerides and can cause build-up of fatty deposits in the liver within weeks of exposure to alcohol
- Hepatomegaly
- Usually reversible
- Alcoholic hepatitis
- Years of exposure (initially reversible)
- Presence of inflammatory cells alongside fatty changes
- More serve symptoms
- RUQ pain
- Jaundice
- Oedema
- Ascites
- Leads to cirrhosis
infections which can cause liver inflammation
hep B and hep c
- Hepatitis B
- Vaccine
- No cure
- Symptoms during acute infection
- Hepatitis C
- No vaccine
- Cure
- Asymptomatic
hepatitis increases
risk of malignancy due to chronic inflmmation
Deposition disease which cause inflammation can be caused by
fat, iron, copper
fat deposition in the liver
Non-alcoholic fatty liver disease (NAFLD)
Non-alcoholic fatty liver disease (NAFLD)
- Insulin resistance
- Accumulation of TAG and other lipids within hepatocytes
- Specific to inflammation present= NASH- Non-alcoholic steatohepatitis- inflammation
iron deposition i.e.
hereditary haemochromatosis
hereditary haemochromatosis
- Increased absorption of iron
- Increased deposition of iron in the liver
- Due to increased levels of ferrite
- Recessive
- Risk of hepatocellular carcinoma
- Treatment: venesection- remove amount of iron in circulation
- Can also affect pancreas
copper deposition in the liver called
wilsons disease
wilsons disease
- Reduced secretion of copper from the biliary system into circulation to be removed
- Therefore accumulation in the tissue
- Low levels of caeruloplasmin ( a ferroxidase enzyme that in humans is encoded by the CP gene)
- Therefore accumulates in liver- site of storage
- Usually in young people
- Symptoms
- CNS
- Seizures
- Memory problems
- CNS
- Treatment- will need liver transplant
Autoimmune disorders which cause inflammation
Autoimmune hepatitis
Primary biliary cirrhois
Primary sclerosing cholangitis
*
-
Autoantibodies which attach liver cells e.g.
- Hepatocytes ASMA, ANA
autoimmune heptitis
autoantibodies which attach liver cellls e.g. hepatocytes ASMA, ANA
Primary biliary cirrhois
anti-mitochondrial antibodies
Primary sclerosing cholangitis
- No anti-mitochondrial antibodies
- Can be linked to UC
Other causes of cirrhosis
- Alpha- antitrypsin
- Glycogen storage
- Budd- chiari
Portal circulation-
the network of veins that drains via the liver into the inferior vena cava
- Three main veins that comprise the portal system:
-
Inferior mesenteric vein
* Drains the descending colon-
Superior mesenteric vein
- Drains the ascending colon and other midgut structures
-
Splenic vein
- Inferior mesenteric vein drains into splenic vein and join with the superior mesenteric vein to form the portal vein
-
Superior mesenteric vein
-
Inferior mesenteric vein
- Portal vein enters the liver and drains it, then forms the hepatic veins which drain into the inferior vena cava
portal hypertension
- Build up of blood within the portal venous system
why does portal hypertension occur
- Due to cirrhosis
- Too much fibrotic tissue
- Not very expansive – needs to be because it drains the whole GI tract
- If its not very expansive veins entering the liver (from portal venous system) will be compressed
- Increase hydrostatic pressure within portal venous system
- Portal hypertension can cause
- ascites
- build-up of pressure in splenic circulation
- blood can shunt from portal system to systemic circulation- varcices
- hepatorenal syndrome
-
Ascites- fluid leakage into abdomen
*
- High hydrostatic pressure forcing water out
- Low albumin would also help this
- Build-up of pressure in splenic circulation causes
splenomegaly (need to feel for spleen and liver on exam)
- Blood can shunt from portal system to systemic circulation
- In normal life there are anastomoses between p. and s. system- not usually used
- If increase in venous pressure in portal system- blood shunts the other way
- Distention at site of anastomoses–> varices
- If increase in venous pressure in portal system- blood shunts the other way
- In normal life there are anastomoses between p. and s. system- not usually used
varices can occur in the
- Oesophagus
- Anal-rectal
- Umbilical
oesophageal varices
- Upper 2/3 drains into oesophageal veins- goes through the azygous drains into the superior vena cava
- Distal portion drains into the left gastric vein- drains into the portal vein
- At the junction where there are veins draining into the main systemic circulation (SVC) is where the pressure builds up.
- Veins are superficial- therefore become dilatedà easy to rupture
- Significant Haematemesis
- Anal-rectal varices
- Between superior (which drain into the mesenteric vein) and middle and inferior rectal vein (internal iliac vein–> drains into IVC)
- Very rarely cause pain or bleed–> patients don’t usually present with these
- Umbilical varices
- Ligamentum teres in adults- usually non functioning in adults
- Can become enlarged
- Caput medusae sign
The biliary system
- Key function of the liver is creating bile which is stored in the gall bladder
- Need a way to get the bile into the gall bladder from the liver and from the gall bladder into the duodenum
outline the route of the biliary system
- Right and left hepatic duct join together to form the common hepatic duct
- Duct from the gall bladder (cystic duct) joins to the CHD–> this forms the common bile duct
- How bile is released into the duodenum
- Pancreas releases enzymes via the pancreatic duct into the common bile duct
- Both bile and pancreatic enzymes leave the common bile duct via the ampulla of vater which is controlled by the sphincter of Oddi into the second part of the duodenum
Both bile and pancreatic enzymes leave the common bile duct via the
ampulla of vater which is controlled by the sphincter of Oddi into the second part of the duodenum
common pathology of the biliary system
gall stones
gall stone are made up of
- Cholesterol
- Bile pigments
- Mixed (cant find on x-ray- usually need ultrasound)
- Risk factors for gallstones
- Diet- high cholesterol
- Women
- Older
- Pregnancies
- Complications of gall stones
- Biliary colic
- acute cholecystitis
- ascending cholangitis
- acute pancreatitis
Biliary colic
- Gall stones happily sitting within gall bladder, but can cause sudden onset of RUQ pain typically a few hours after eating a fatty meal
- Due to cholecystokinin (CCK) release after meal, which causes the gall bladder contract and push a gallstone up against the neck of the gall bladder- temporary obstruction of biliary duct
- Constant pain- can last for a long time and then ease for a while
- Treatment- pain relief and removal
- Acute cholecystitis
- RUQ pain- caused by full impaction of stone in cystic duct
- Inflammatory features
- Positive Murphy sign place a hand on right side of the patients stomach and ask them to take a deep breathe in- will push gall bladder down and cause them to take a sharp breathe in pain (wont happen on left hand side)
- Treatment- pain relief and Ab, will need to be removed
- Ascending cholangitis
- Statis due to blockage of Common Bile Duct by stone
- Infection of biliary tree
- Charcots triad
charcots triad
- Inflammation, RUQ pain, jaundice (when stone reaches common bile duct)
- Positive Murphy sign
place a hand on right side of the patients stomach and ask them to take a deep breathe in- will push gall bladder down and cause them to take a sharp breathe in pain (wont happen on left hand side)
Acute pancreatitis
- Stone in common bile duct after the point when the pancreatic duct has joined the common bile duct
- Autodigestion of pancreas- due to enzyme not being able to be released into duodenum
symptoms and signs of acute pancreatitis
- Epigastric (back) pain
- Vomiting
- Cullen’s and Grey Turners sign
- Look for raised levels of amylase and lipase in the blood
- CT scan
management of acute pancreatitis
- Management
- Lots of fluids
- Antibiotics
- Pain relief
