Lecture 4: Structure and function of the liver Flashcards
Name some the liver functions?
- Amino acid, carbohydrate and lipid metabolism
- Storage of proteins, glycogen, vitamins and metals
- Plasma protein and enzyme synthesis
- Detoxification of endogenous and exogenous products
- Production of bile
- Immune functions
The liver is located in which region of the 9 regions of abdomen
Right hypochondria region and epigastric region
What are the arteries that supply the blood to the liver
Hepatic artery proper (25%) – supplies the non-parenchymal structures of the liver
Hepatic portal vein (75%) – supplies the liver with partially deoxygenated blood, carrying nutrients absorbed from the small intestine. This is the dominant blood supply to the liver parenchyma, and allows the liver to perform its gut-related functions, such as detoxification.
Describe the venous drainage of the liver?
- Venous drainage of the liver is achieved through hepatic veins.
- The central veins of the hepatic lobule form collecting veins which then combine to form multiple hepatic veins.
- These hepatic veins then open into the inferior vena cava.
What are the 3 structures that make up the portal triad?
- Hepatic artery proper
- Hepatic portal vein
- Bile ducts
The majority of the arterial supply to the liver comes from which vessel?
Hepatic portal vein (75%)
Name the cells that make up the parenchyma tissue of the liver?
- The liver parenchyma is the functional tissue
- Hepatocytes make up the majority of the parcenchyma tissue
The liver secretes bile into the duodenum via which vessel
The common bile duct
Name the cells that make up the non-parenchyma tissue of the liver?
The non parenchymal cells of the liver include populations of:
- Cholangiocytes (epithelial cells)
- Sinusoidal endothelial cells
- Stellate cells
- Kupffer cells
- Intrahepatic lymphocytes
Combined they make up 40% of the cells in the liver.
Name the components of bile
- Bilirubin
- Bile acids/salts
- Mucin
Brief description of cirrhosis?
- Liver cirrhosis often results from chronic alcoholism or infection with hepatitis viruses.
- In this disease, portions of the liver are repeatedly destroyed and replaced at the expense of the hepatic architecture. Scarring disrupts the sinusoids and this results in the backup of blood in the portal vein and portal hypertension.
- Hepatocytes are still present, but there is a dense connective tissue bands that have formed throughout the sinusoids. As a result, the sinusoids would function less well at exposing the hepatocytes to the blood; the hepatocytes would do less of a good job at filtering the blood.
Name the possible causes of cirrhosis
- Alcohol or alcohol-like
- Hepatitis incl. viral
- Biliary disease
- Unknown
- Haemochromatosis
List the possible complications of cirrhosis
- Portal hypertension
- Cirrhosis ↑ resistance to blood flow through liver thus ↑ pressure in portal circulation, causing:
- Portal-systemic shunts and varices
- Ascites - increase in free fluid in the abdomen
- Splenomegaly - enlargement of the spleen
- Cirrhosis ↑ resistance to blood flow through liver thus ↑ pressure in portal circulation, causing:
- Liver failure
- Hepatocellular (liver) cancer
ALP is ________ in conditions causing _______ tract obstruction, with elevations proportional to the degree of obstruction.
Increased
Biliary
________ is a group of enzymes found mainly in bone, liver, intestines and placenta.
ALP
In post hepatic jaundice, ALT levels rise markedly.
A) True
B) False
B) False
(ALT/AST) is greater than (ALT/AST) in metatastic disease of the liver.
A) AST
B) ALT
Where is conjugated bilirubin is converted to urobilinogen.
In the small intestine
________ transports unconjugated bilirubin to the liver.
Albumin
_________ is responsible for the yellow coloring in jaundice.
Bilirubin
Which factors are we testing for in the blood test used to assess liver function?
- Alanine transaminase (ALT)
- Aspartate aminotransferase (AST)
- Alkaline phosphatase (ALP)
- Gamma-Glutamyltransferase (GGT)
- Bilirubin
- Albumin
- Prothrombin time (PT)
Describe the pattern of liver function test results for obstructive causes
High bilirubin
High ALP
Normal ALT
A greater than 10-fold increase in ALT and a less than 3-fold increase in ALP suggests?
A predominantly hepatocellular injury
A less than 10-fold increase in ALT and a more than 3-fold increase in ALP suggests ?
Cholestasis- post-hepatic obstruction in the biliary tree
A raised ALP in the absence of a raised GGT is suggestive of?
Non-hepatobiliary pathology- particularly bone related disorders.
Alkaline phosphatase is also present in bone and therefore anything that leads to increased bone breakdown can elevate ALP.
A markedly raised ALP with a raised GGT is highly suggestive of?
Cholestasis- obstructive
_____ bilirubin is water-insoluble and therefore doesn’t affect the colour of the patient’s urine.
_____ bilirubin, however, can pass into the urine as urobilinogen, causing the urine to become darker.
A) Unconjugated bilirubin
B) Conjugated bilirubin
If bile and pancreatic lipase’s are unable to reach the bowel because of a blockage (e.g. in obstructive post-hepatic pathology), fat is not able to be absorbed, resulting in stools appearing ___
Pale
The colour of the stools can be used to differentiate the causes of jaundice.
Normal urine + normal stools is suggestive of which kind of cause of the jaudice?
A) Pre-Hepatic
B) Hepatic
C) Post-hepatic
A) Pre-hepatic
Normal urine: High level of Unconjugated bilirubin but this has no effect on the urine colour.
Normal stool: bile and pancreatic lipase’s are able to reach the bowel
The colour of the stools can be used to differentiate the causes of jaundice.
Dark urine + normal stools is suggestive of which kind of cause of the jaudice?
A) Pre-Hepatic
B) Hepatic
C) Post-hepatic
B) Hepatic
High level of conjugated bilirubin causing the darkening of the urine
The colour of the stools can be used to differentiate the causes of jaundice.
Dark urine + pale stools is suggestive of which kind of cause of the jaudice?
A) Pre-Hepatic
B) Hepatic
C) Post-hepatic
C) Post-hepatic (obstructive)
Dark urine: high level of conjugated bilirubin
Pale stool: Bile and pancreatic lipase cannot get into the bowel so the fat is not broken down causing pale stoole
An isolated rise in bilirubin is suggestive of
A pre-hepatic cause of jaundice.
Either:
- Gilbert’s syndrome (most common cause)
- Haemolysis
ALT > AST is seen in which condition
Chronic liver disease
AST > ALT is seen in which condition
Cirrhosis and acute alcoholic hepatitis
Which part liver function test indiciates jaundice?
Bilirubin
Which parts of the liver function test actually indicates the cause e.g. prehepatic, hepatic or post-hepatic
- ALT
- AST
- ALP
- GGT
Which part of the liver function test indicates how functional the liver is?
- Bilirubin
- Albumin
- Prothrombin time (PT)
Fill in the blanks of this image of the liver
