Part 6: Liver and Biliary Tract Flashcards
The liver is divided into 2 main surfaces…
Diaphragmatic and visceral
The diaphragmatic surface of the liver can be further divided into…
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
Describe the visceral surface of the liver
Inferior surface, slopes downwards, forwards and to the right. Main feature is H pattern of structures
Describe the H pattern of structures of the visceral surface of liver
Cross piece: Porta hepatis (hilum of liver)
Right limb: IVC and gallbladder
Left limb: fissures for ligamentum venosum and teres
Where does the falciform ligament lie?
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
Describe the porta hepatis
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
Where is the bare area?
To R of IVC, shape of triangle. IVC as base and sides of triangle upper and lower coronary ligament. Apex is right triangular ligament.
Where does the coronary ligament lie?
Surrounds the bare area with upper ligament upper border and lower ligament lower border. Apex forms R triangular ligament.
What are the lobes of the liver?
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
What are the segments of the liver?
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
What is the difference between branching shape of arterial vs venous hepatic vasculature?
Arterial: Y-shaped
Portal vein: T shaped
What are the branches of the hepatic artery?
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
Describe the lymph drainage of the liver
Drains via arterial supply to nodes in porta hepatis (hepatic nodes) and eventually to coeliac nodes
What is the micro structure of liver?
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.
What are the parts of the gallbladder?
Fundus
Body
Neck
What is the structure of gallbladder?
Fibromuscular sac with smooth muscle wall
Simple columnar epithelium
Mucous secreted by columnar epithelium (not goblet cells) and only in neck
What is blood supply of gallbladder?
Cystic duct (branch of R hepatic) Also bed of gallbladder fossa (can supply gallbladder if cystic duct blocked)
What is Carlot’s triangle?
Triangle formed by liver, common hepatic duct and cystic duct. Useful on cholecystectomy.
How long is common hepatic duct?
4cm
4mm diameter
Cystic duct usually lies on right side about 1cm above duodenum but many variations exist
How long is bile duct and how many parts?
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
What is the nervous supply of liver?
sympathetic from coeliac ganglia
Parasympathetic from L vagal trunk
What is the nervous supply of gallbladder?
Sympathetic - coeliac ganglia but sometimes run in phrenic nerve hence referred pain to shoulder
Parasympathetic - anterior vagal trunk
Portal vein is formed by what and has what other major tributaries?
Formed by SMV and splenic vein.
Receives R+L gastric, superior pancreaticoduodenal veins, cystic and periumbilical veins
What are the portal-systemic anastomosis?
Lower oesophagus Upper end anal canal Bare area of liver Periumbilical region Retroperitoneal regions
What does the portal vein develop from?
Vitelline veins become portal vein and IVC and hepatic veins
