liver

Question 1

what vessels supply blood to the liver

Answer 1

• hepatic artery - branch of the coeliac axis (25%)

- portal vein - drains most of the GI tract and spleen (75%)

Question 2

what is the network between hepatocytes

Answer 2

bile canaliculi which join to form thin bile ductules near the portal tract which in turn enter bile ducts in the portal tracts

• the hepatic ducts join at the porta hepatitis to form the common hepatic duct

Question 3

what connects the gall bladder to the lower end of the common hepatic duct

Answer 3

cystic duct

Question 4

what does the gallbladder store

Answer 4

It lies under the right lobe of the liver and stores and concentrates hepatic bile - it has a capacity of 50ml

Question 5

what forms the central bile duct

Answer 5

cystic and hepatic ducts, narrowing at its distal end to pass into the duodenum

• the CBD and pancreatic duct open into the 2nd part of the duodenum through a common channel at the ampulla of vater

Question 6

where is the liver found

Answer 6

the right hyporchondrium

Question 7

how many segments make up the liver

Answer 7

8 - each segment has its own portal pedicle, permitting individual resection at surgery

Question 8

what are sinusoids

Answer 8

low pressure vascular channels that receive blood from terminal branches of the hepatic artery and portal vein at the periphery of lobules and deliver it into central veins.

Question 9

what is the caudate lobe

Answer 9

independent part of the liver, supplied by the right and left hepatic artery and portal vein. Blood from the caudate lobe drains directly into the vena cava

Question 10

what is the acinus

Answer 10

the functional hepatic unit which consists of parynchyma supplied by teh smallest portal tracts containing portal vein radicals, hepatic arterioles and bile ductules

Question 11

what is jaundice

Answer 11

Jaundice is a condition in which the skin, whites of the eyes and mucous membranes turn yellow because of a high level of bilirubin, a yellow-orange bile pigment.

Question 12

when is jaundice detectable clinically

Answer 12

when serum bilirubin is over 50 umol/L

Question 13

what can jaundice be divided into

Answer 13

• haemolytic jaundice
• congenital hyperbilirubinaemia
• cholestatic jaundice

Question 14

what is haemolytic jaundice

Answer 14

Increased bilirubin load for the liver cells due to increased breakdown of RBCs

• usually mild jaundice

Question 15

what causes haemolytic jaundice

Answer 15

Haemolytic anaemia

Question 16

clinical features of haemolytic jaundice

Answer 16

• jaundice
• splenomegaly
• gallstones
• leg ulcers

Question 17

what is congenital hyperbilirubinaemia

Answer 17

defects in conjugation

Question 18

what is unconjugated bilirubin

Answer 18

not water soluble and therefore doesn’t pass into the urine

Acholuric jaundice = Jaundice without bile pigments in the urine.

Question 19

what are unconjugated types of jaundice

Answer 19

• Gilberts syndrome

- Crigler-Najjar syndrome

Question 20

what are conjugated types of jaundice

Answer 20

• Dubin-Johnson and Rotors syndromes
• Benign recurrent intrahepatic cholestasis
• Progressive familial intrahepatic cholestasis syndromes

Question 21

what is cholestatic jaundice (acquired)

Answer 21

cholestatic, or obstructive, jaundice, occurs when essentially normal liver cells are unable to transport bilirubin either through the hepatic-bile capillary membrane, because of damage in that area, or through the biliary tract, because of anatomical obstructions such as gallstones or cancer.

Question 22

what is extra hepatic cholestasis

Answer 22

due to a large duct obstruction of bile flow at ant point in the biliary tract distal to the bile canaliculi

Question 23

what is intra hepatic cholestasis

Answer 23

occurs because of the failure of bile secretion, which may be caused by intrinsic defects in bile secretion of inflammation in the intrahepatic ducts

Question 24

what causes extra hepatic cholestasis

Answer 24

• common duct stones
• Carcinoma in the bile duct, head of pancreas or ampulla
• Biliary stricture
• Sclerosing cholangitis
• Pancreatic pseudocyst

Question 25

what causes intra hepatic cholestasis

Answer 25

- viral hepatitis - drugs - alcohol - cirrhosis - autoimmune cholangitis

Question 26

what are the signs and symptoms of extra and intra hepatic cholestasis

Answer 26

- jaundice - pale stools - dark urine - serum bilirubin is conjugated

Question 27

what are the 2 most useful tests for jaundice

Answer 27

- viral markers ( for HAV, HBV, HCV ) - ultrasound - to exclude an extra hepatic obstruction and to diagnose any features comparable with chronic liver disease

Question 28

what is acute liver failure

Answer 28

acute liver injury with encephalopathy and deranged coagulation (INR>1.5) in a patient with a previously normal liver

Question 29

what causes acute liver failure

Answer 29

- viruses - drugs eg paracetamol, antibiotics, antidepressants - toxins - hepatic failure in pregnancy - vascular causes - metabolic causes - malignancies

Question 30

what are clinical features of acute liver failure

Answer 30

- jaundice - small liver - signs of hepatic encephalopathy - Fetor hepaticus - fever - vomitting - hypotension - hypoglycaemia - spascitiy - cerebral oedema

Question 31

what investigations should be carried out for acute liver failure

Answer 31

- routine tests - there is hyperbilirubunaemia, high serum aminotransferases and low levels of coagulation factors . Aminotransferases are not useful indicators of the course of the disease as they tend to fall along with the albumin with progressive liver damage - an electroencephalogram is sometimes helpful in grading encepathology - ultrasound will define size of liver and may indicate underlying liver pathology

Question 32

management of acute liver failure

Answer 32

- no specific treatment - supportive therapy - 20% mannitol if increased intracranial pressure - suspected infection = antibiotics - transplant

Question 33

what is autoimmune hepatitis

Answer 33

Inflammatory liver disease of unknown cause characterized by suppressor T cell defects with autoantibodies directed against hepatocyte surface antigens. Type 2: children and young adults, type 1: adults

Question 34

signs and symptoms of autoimmune hepatitis

Answer 34

Most present with autoimmune signs: fever, malaise, urticarial rash, polyarthritis, pleurisy, pulmonary infiltration or glomerulonephritis. Also may present with signs of chronic liver disease

Question 35

what are investigation findings for autoimmune hepatitis

Answer 35

Raised AST, ALT, serum bilirubin and Alk Phos, hyper gammaglobulinaemia (esp IgG), positive autoantibodies

Question 36

how to manage autoimmune hepatitis

Answer 36

- prednisolone daily for at least 2 weeks followed by a slow reduction to a maintenance dose - Azathrhioprine should be added as a steroid sparing agent