7. Anatomy of the liver and biliary tree

Question 1

Where in the body is the liver located?

Answer 1

In the right hyperchondrium i.e. the right upper quadrant of the body

Question 2

What is the falciform ligament?

Answer 2

This is a reflection of the peritoneum

Question 3

What is the ligamentum teres?

Answer 3

This is contained within the falciform ligament and is the remains of the umbilical cord (specifically the left umbilical vein)

Question 4

What are the lobes of the liver and where can these be seen?

Answer 4

Right lobe - larger lobe on the right hand side of the liver
Left lobe - smaller lobe on the left hand side of the liver
Quadrate lobe - on the visceral surface of the liver at the anterior aspect
Caudate lobe - on the visceral surface at the posterior aspect close to the ICV - this lobe has a tail

Question 5

What are the hepatic recesses and where are these located?

Answer 5

Subphrenic recesses - left and right between the diaphragm and the liver on either side of the falciform ligament

Subhepatic recess - located between the inferior surface of the liver and the transverse colon

Morison’s pouch - this is in the posteriosuperior aspect of the right subhepatic space - this is the deepest part of the peritoneal cavity when supine and so this is where fluidis likely to collect in a bedridden patient

Question 6

What is the blood supply to the liver?

Answer 6

25% is from the coeliac trunk

75% is from the hepatic portal system of veins

Question 7

What is different about the hepatic portal vein?

Answer 7

This is not a true vein in that it delivers blood from the GI tract and the spleen to the capillaries of the liver rather than directly to the heart

Question 8

Give the blood supplies to the different parts of the gut and where their roots are

Answer 8

Coeliac trunk to the foregut at T12
Superior mesenteric artery to the midgut at L1
Inferior mesenteric artery at L3

Question 9

What is cirrhosis?

Answer 9

This is scarring of the liver caused by continuous long-term liver damage
The scar tissue replaces healthy tissue in the liver and prevents the live from working properly
The damage cannot be reversed and can eventually lead to liver failure and death

Question 10

What is the most important consequence of cirrhosis?

Answer 10

Because of the fibrosis and scarring of the liver, it cannot perfuse into the liver parenchyma properly
This results in an increased pressure within the liver and this becomes portal hypertension

Question 11

What is portal hypertension and what is a consequence of this?

I.e. How is this calculated?

Answer 11

Portal hypertension is defined when the portal pressure gradient is greater than 10
Normal portal pressure - 9mmHg
IVC - 2-6mmHg so when the difference between these two is greater than 10 then this is portal hypertension

This can lead to splenomegaly

Question 12

What are systemic porto-anastomoses and how does this relate to portal hypertension?

Answer 12

This is where there is an anastomoses between the portal system and the systemic system
When there is portal hypertension, the blood at the anastomoses will want to travel in the direction of the least resistance (to the systemic system) and this can cause the development of certain structures e.g. varices which can then lead to very heavy bleeds that can result in death

Question 13

Where are the regions of the porto-systemic anastomoses?

Answer 13

Oesophagus
Retroperitoneum
Ano-rectal junction
Anterior abdominal wall

Question 14

Describe what occurs at the oesophagus during portal hypertension

Which veins are involved?

Answer 14

Oesophageal varices can form due to anastomoses of the left gastric vein to the oesophageal veins
Patients present with haematemesis (vomiting of blood)

Question 15

Describe what occurs at the retroperitoneum during portal hypertension

Which veins are involved?

Answer 15

Between the lumbar veins and the SMV and IMV

Can lead to a retroperitoneal haemorrhage and this can present as bruising around the flanks aka. Grey Turner’s sign

Question 16

Describe what occurs at the ano-rectal junction during portal hypertension

Answer 16

Ano-rectal varices - the membranes of these are very delicate and so they can burst and lead to a very heavy bleed

Question 17

Describe what happens at the anterior abdominal wall during portal hypertension

Answer 17

Ascities i.e. fluid in the periteoneal space

Caput Medusae

Question 18

Draw the biliary tree

Answer 18

Anatomy folder

Question 19

Which bile ducts drain from which region of the liver?

Answer 19

Right hepatic duct - from the right lobe
Left hepatic duct - from the left hepatic lobe, caudate and quadrate lobes
The ducts then join and the bile leaves via the common hepatic duct

Question 20

What is the blood supply to the gallbladder?

Answer 20

Cystic artery

Question 21

When considering the biliary tree, where is bile coming from/going to?

Answer 21

Bile travels from the liver and the pancreas to the small intestine - this is half of the bile
The other half of the bile travels to the gallbladder for storage

Question 22

When does jaundice occur from a gallstone?

Answer 22

If the bile is blocked from entering the small intestine and instead remains in the circulation - jaundice

Question 23

Will a gallstone in the cystic duct cause jaundice?

Answer 23

No

Question 24

Will a gallstone in the common bile duct cause jaundice?

Answer 24

Yes

Question 25

Will a gallstone in the hepatopancreatic ampulla cause jaundice?

Answer 25

Yes