Part 6: Liver and Biliary Tract

Question 1

The liver is divided into 2 main surfaces…

Answer 1

Diaphragmatic and visceral

Question 2

The diaphragmatic surface of the liver can be further divided into…

Answer 2

Anterior: Related to heart, diaphragm, lung, pleura, ribs (6-10 R, 6-7 L)
Superior: Heart and pericardium centrally with lung and pleura laterally
Posterior: Posterior wall
Right surfaces: Ribs 7-11

Question 3

Describe the visceral surface of the liver

Answer 3

Inferior surface, slopes downwards, forwards and to the right. Main feature is H pattern of structures

Question 4

Describe the H pattern of structures of the visceral surface of liver

Answer 4

Cross piece: Porta hepatis (hilum of liver)
Right limb: IVC and gallbladder
Left limb: fissures for ligamentum venosum and teres

Question 5

Where does the falciform ligament lie?

Answer 5

From centre of liver to ligamentum teres notch. Splits and sweeps to L forming L triangular ligament and to R forming upper layer of coronary ligament. Connects to inferior diaphragm with L margin and extends down to attach to rectus sheath/anterior abdominal wall

Question 6

Describe the porta hepatis

Answer 6

Hlium of liver. Enclosed between 2 layers of lesser omentum which also attach to ligamentum venosum. Perforated by L+R hepatic ducts, L+R hepatic arteries and portal vein. Lie VAD with ducts anterior

Question 7

Where is the bare area?

Answer 7

To R of IVC, shape of triangle. IVC as base and sides of triangle upper and lower coronary ligament. Apex is right triangular ligament.

Question 8

Where does the coronary ligament lie?

Answer 8

Surrounds the bare area with upper ligament upper border and lower ligament lower border. Apex forms R triangular ligament.

Question 9

What are the lobes of the liver?

Answer 9

Anatomically divided into R and L lobes by falciform ligament.
Right: to R of R limb of H
Left: to L of ligamentum teres
Caudate: Bordered by IVC, ligamentum venosum. Lies posteriorly. Connected to R via caudate process.
Quadrate: Between gall bladder fossa and fissure for ligamentum teres.

Quadrate and caudate functionally belong to L lobe

Question 10

What are the segments of the liver?

Answer 10

I: Caudate
II: L lateral
III: lateral part L medial
IV: Medial part L medial
V: Lower part R anterior
VI: Lower part R posterior
VII: Upper part R posterior
VIII: Upper part R anterior

Question 11

What is the difference between branching shape of arterial vs venous hepatic vasculature?

Answer 11

Arterial: Y-shaped

Portal vein: T shaped

Question 12

What are the branches of the hepatic artery?

Answer 12

Correspond to segments
R: anterior and posterior branches
L: medial and lateral branches
No communication between L+R halves of liver in arterial supply, mixing of venous drainage

Question 13

Describe the lymph drainage of the liver

Answer 13

Drains via arterial supply to nodes in porta hepatis (hepatic nodes) and eventually to coeliac nodes

Question 14

What is the micro structure of liver?

Answer 14

Centre is lobule - region of liver hexagonal shape with central vein and sinusoids radiating to periphery.
At corners of lobule lies portal triad of artery, vein and duct.
The acinus is the functional component - anastomosis of vascular and bilary channels leading towards portal vein.

Question 15

What are the parts of the gallbladder?

Answer 15

Fundus
Body
Neck

Question 16

What is the structure of gallbladder?

Answer 16

Fibromuscular sac with smooth muscle wall
Simple columnar epithelium
Mucous secreted by columnar epithelium (not goblet cells) and only in neck

Question 17

What is blood supply of gallbladder?

Answer 17

Cystic duct (branch of R hepatic)
Also bed of gallbladder fossa (can supply gallbladder if cystic duct blocked)

Question 18

What is Carlot’s triangle?

Answer 18

Triangle formed by liver, common hepatic duct and cystic duct. Useful on cholecystectomy.

Question 19

How long is common hepatic duct?

Answer 19

4cm
4mm diameter
Cystic duct usually lies on right side about 1cm above duodenum but many variations exist

Question 20

How long is bile duct and how many parts?

Answer 20

8cm long and 8mm wide
Upper (suprduodenal) - lies in free edge lesser omentum
Middle (retroduodenum)- lies behind D1, slopes down to R
Lower (paraduodenal) - slopes further to R behind head of pancreas and D2 - joining pancreatic duct

Question 21

What is the nervous supply of liver?

Answer 21

sympathetic from coeliac ganglia

Parasympathetic from L vagal trunk

Question 22

What is the nervous supply of gallbladder?

Answer 22

Sympathetic - coeliac ganglia but sometimes run in phrenic nerve hence referred pain to shoulder
Parasympathetic - anterior vagal trunk

Question 23

Portal vein is formed by what and has what other major tributaries?

Answer 23

Formed by SMV and splenic vein.

Receives R+L gastric, superior pancreaticoduodenal veins, cystic and periumbilical veins

Question 24

What are the portal-systemic anastomosis?

Answer 24

Lower oesophagus
Upper end anal canal
Bare area of liver
Periumbilical region
Retroperitoneal regions

Question 25

What does the portal vein develop from?

Answer 25

Vitelline veins become portal vein and IVC and hepatic veins