Liver Flashcards
what are the two main blood vessels bringing blood to the liver called
the hepatic artery and portal vein
what happens to the blood once it reaches the liver
The nutrient rich blood reaches the liver and hepatocytes filter and metabolises drugs, vitamins before releasing them into the systemic circulation
what is the blood vessel taking blood away from the liver called
hepatic vein
what is the main function of hepatocytes
these produce bile which is collected in the bile duct and drains towards the gall bladder where it can be secreted into the upper GI tract
the liver produces bile salts. What is the use for bile salts and why it is important?
they allow the emulsification of fats so our body can absorb fat and allow the absorption of fat soluble vitamins like vitamin A, D, E and K
where are bile salts stored, released into and what triggers this?
stored in the gall bladder and relased into the duodenum in response to food in the GI tract
another function of the liver is that it metabolises…
microbes and toxins absorbed from the gut, nutrients and drugs
how does the liver metabolise microbes
phagocytic cells which grab dead cells, bacteria and infected cells
Describe the exocrine function of the liver
-Excretes bilirubin - produced from breakdown of Hb from dead RBC
- Bile salts
-Metabolises and circulates Cholesterol – cholesterol is important for hormones and vitamin D)
Describe the synthesis function of the liver
- Produces Clotting factors
- Produces Antibodies
- Produces Albumin – albumin is a main plasma protein which Is needed to maintain osmosis in cells
how many phases of drug metabolism are there
2 phases
Phase 1 and Phase 2
what enzyme group is required for drug metabolism
Cytochrome p450
what is the purpose of phase 1
makes the molecule more water soluble
what is the purpose of phase 2
makes the molecule less active and more soluble
what is the ultimate result of drug metabolism
drugs can be filtered, do not need to be bound to plasma protein, less fat soluble, can be excreted in the kidney
what is first pass metabolism
this is when a drug passes through a specific organ and leave the organ ready for excretion or completely deactivated
what is the result of first metabolism
if a drug is subjected to first pass metabolism it means the body clears the drug quickly making the drug less effective. So some drugs may not work depending on how you administer them
which organs can first pass metabolism occur in
Liver, lung, gut and other organs
give an example of a drug that needs to be injected instead of taken orally to avoid first pass metabolism
Lidocaine
how does codeine react to first pass metabolism
codeine is converted into a more active form when it undergoes first pass metabolism in the gut and turns into morphine
what are the effects of drugs on cytochrome p450 enzymes
They can induce or inhibit the enzyme. So if drug A is ingested it can induce cyt p450 to induce metabolism of drug B which can be a downside or drug A could inhibit cyt p450 so less metabolism of drug B
explain the drug relationship between warfarin and erythromycin
- Warfarin is metabolised by the cytomchrome p450 pathway
- Erythromycin inhibits cyt p450 so warfarin less likely to be metabolised so warfarin stays in body and activity in body goes up and so does the INR (pt bleeding for longer)
- Miconazole does the same thing
what are the physical effects of liver disease
- Portal hypertension - increased pressure in portal vein caused by blood clot or scarring in liver. Often diagnosed by ascites.
- Oesophageal varices (caused by portal hypertension - increased pressure in portal vein pushes blood to surrounding blood vessels such as those in oesophagus lining. Extra blood causes varices- swollen blood vessels)
- Ascites – this is fluid retention in abdominal cavity due to portal hypertension and low albumin level due to liver disease – patient stick thin but big belly
describe the signs that someone with jaundice may have
yellow skin tone, sclera has yellow discolouration, palms have yellow tone
finger clubbing is a sign of liver disease but is it related to liver disease exclusively
No (also seen in emphysema, GIT diseases)
dupuytren’s contracture is a sign of liver disease. Describe this
contracture of the pinky and ring finger which isn’t painful but can be debilitating
gynaecomastia is a sign of liver disease describe this
this is when the sex hormones are affected by liver disease so a male body becomes more feminine like the development of breasts
sialosis is another sign of liver disease but what else can cause this
diabetes and chronic alcohol abuse
describe sialosis presentation
painless bilateral swelling of salivary gland usually in the parotid it is smooth and not bumpy (like tumour)
what can be used to test for liver disease
Liver function test which checks hormone levels like bilirubin or INR test