WEEK 16 Flashcards
(42 cards)
At low levels of consumption, alcohol is converted to ______ and _____ for excretion via the _______, _______ and _________
- CO2
- H2O
- urine
- lungs
- sweat
At higher levels of consumption, ethanol is converted to acetaldehyde by ___________ in gastric mucosal cells and ________ and then undergoes lipogenesis to form fatty acids and glycerol. These can accumulate in hepatocutes leading to inflammation (_________) that impairs liver function.
- alcohol dehydrogenase
- hepatocytes
- hepatitis
There are many mechanisms by which alcohol damages the human body: it is directly _____, the metabolite ___________ is carcinogenic, it induced _____ change, inflammation and fibrosis in the liver, it induces enzymes like ______, and it prevents absorption and storage of essential nutrients (particularly __ vitamins).
- toxic
- acetaldehyde
- fatty
- cp450
- B
Describe the 5 steps of liver disease
- Fatty liver — fats are deposited in the cytoplasm of the hepatocyte
- Hepatitis — hepatic leucocytosis and loss of function
- Fibrosis — reversible deposition of pericellular fibrous bands
- Cirrhosis — irreversible nodules that comprise a hypo plastic hepatocyte surrounded by fibrous tissue
- Hepatocellular carcinoma — genetic changes inside the cell
Alcohol is a CNS ______ at low levels of consumption
Stimulant
Alcohol is _________, allowing it to easily cross the BBB and act on neurones
Lipophilic
At very high levels of consumption, alcohol acts on ________ centres in the brainstem
Respiratory
Alcohol is a CNS __________ at high levels of consumption, acting via ____ receptors
- depressant
- GABA
Chronic alcohol consumption interferes with absorption and utilisation of vitamin B1 (__________), which is essential for CNS ______ metabolism
- thiamine
- glucose
Name 4 pre-hepatic causes of jaundice
- haemolytic anaemia
- drugs
- Gilbert’s syndrome
- Crigler-Najjar syndrome (rare)
Name hepatic causes of jaundice
- viral infection
- alcohol
- NAFLD
- autoimmune disorders (primary biliary cholangitis, primary sclerosing cholangitis)
- malignancy of biliary system (HCC, cholangiocarcinoma, gallbladder cancer)
- metabolic (haemochromatosis, Wilson’s disease)
- drugs
Name 5 drugs that can cause jaundice
- ciprofloxacin
- co-amoxiclav
- phenytoin
- erythromycin
- nitrofurantoin
Name 4 post-hepatic causes of jaundice
- gallstones
- surgical strictures
- extra-hepatic malignancy (pancreatic cancer)
- pancreatitis
What stigmata of chronic liver disease may you see as a result of high oestrogen levels?
- Palmar erythema
- Spider naevi
- Gynaecomastia
- Loss of secondary body hair (in males)
- Male genital atrophy
What stigmata of chronic liver disease may you see as a result of low albumin?
Leukonychia
What stigmata of chronic liver disease may you see as a result of portal hypertension?
- caput medusae
- dilated anterior abdominal wall veins
- ascites
What else may you see in chronic liver disease?
- signs of hepatic encephalopathy including a liver flap (asterixis)
- muscle loss (sarcopenia)
What symptoms may indicate an obstructive jaundice?
- dark urine
- pale stools
- itching
What is jaundice and what are normal plasma bilirubin levels?
NICE defines jaundice as the yellow pigmentation of the skin, sclera and mucous membranes resulting from raised plasma bilirubin. Normal plasma bilirubin levels are <21mmol/L
What is bilirubin?
A breakdown product of Haem molecules in red cells
Describe the pre-hepatic metabolism of red cells
- as red cells in the blood reach the end of their lifecycle (approx 120 days) they are phagocytosed by macrophages
- this breaks haemoglobin down to Haem and globin
- Haem is then broken down into iron and protoporphyrin
- protoporphyrin is then broken down into unconjugated bilirubin (not water-soluble)
- this mainly takes place in the spleen
- albumin in the blood then binds to unconjugated bilirubin and transports it to the liver
Describe the hepatic metabolism of red cells
- Unconjugated bilirubin is taken up by hepatocyte in the liver and is conjugated by an enzyme called uridine glucoronyl transferase, creating conjugated bilirubin = water soluble
- here the conjugated bilirubin is secreted into bile duct and stored in the gallbladder as bile
Describe the post hepatic metabolism of red cells
- when you eat, particularly fatty food, bile is excreted from the gallbladder into the duodenum
- conjugated bilirubin in the bile is converted into urobilinogen by microbes in the small intestine
- some of this urobilinogen is reabsorbed into the blood, converted into urobilin and either sent back to the liver or excreted by the kidneys giving urine its yellow colour
What is a Whipple procedure?
—> Aka pancreaticoduodenectomy
The Whipple procedure is an operation to treat tumors and other conditions in the pancreas, small intestine and bile ducts. It involves removing the head of the pancreas, the first part of the small intestine, the gallbladder and the bile duct.
It’s often used to treat pancreatic cancer that hasn’t spread beyond the pancreas.