Unit 8: Liver and pancreas and portal system Flashcards
What are the different surfaces of the liver and Saha structures do they border with?
The anterosuperior surface = diaphragm
The posteriorinferior surface = visceral surface
What ligaments can be found on the anterior surface of the liver?
The right and left coronary ligament
THe falciform ligament
The ligamentum teres
What is the function of the right and left coronary ligamen of the liver?
Form part of the peritoneum reflection that attaches the superior surface of the liver to the diaphragm
What is the function of the falciform ligament of the liver?
Attaches the liver to the anterior abdominal wall
WHat is the function of the ligamentum teres in the liver?
In an embryological remanant of the umbilical vein that exists on the free edge of falciform ligament
What are some ligaments on the posterior liver surface?
The posterior folds of the left and right coronary ligament
Triangular ligaments x2
Ligamentum venosum
Ligamentum teres
What is the function of the posterior folds of the left and right coronary ligament in relation to the liver?
Help hold the liver to the posterior abdominal wall
What is the triangular ligament made from? And what is its function in relation to the liver?
Made from the joining of the anterior and posterior folds of the coronary ligaments
Help anchor to the posterior abdominal wall
What is the bare area of the liver?
What does it attach to?
Area on the superior surface of the liver that attaches directly to the diaphragm
Is margined by the anterior/posterior left/right coronary ligaments and the triangular ligaments.
What is the function and location of the ligamentum venosum of the liver?
Is found on the posterior surface between the left lobe and the caudate lobe
Is a remnant of the ductus venous from the embryo
What two ligaments form the lesser omentum?
The heptogastric
The heptoduodenal
Describe the lobes of the liver
Large left and large right - seen anteriorly
Two additional lobes on the posterior surface - caudate (superior) and quadrate (inferior)
Why and how is the liver split into segments?
Split into 8 segments
Each segment is supplied by its own portal traid
This is important to identify the location of liver problems or if parts of the liver are being operated on, will try to only damage the necessary segments
How are the segments of the liver numbered?
The caudate lobe in lobe number one (only seen on the posterior surface)
When looking at the posterior sruface the lobes can then be numbered in an anticlockwise fashion
When looking at the anterior surface the lobes should be numbered in a clockwise fashion (remember caudate not seen) so start at most left and superior.
Lobe 4 is split into a (superiorly) and b (inferiorly)
How is the liver split into the left and right lobes?
Semgnet 1 to 4 are on the left
This division from the right is by an invisible strucutre called the cantlie line - this is where the middle hepatic vein will run internally
This division is NOT by the falciform ligament
What are the inwards sources of blood to the liver?
The portal vein
The proper hepatic artery (a branch of the coeliac trunk)
What is the venous drainage of the liver?
Each lobule contains a central vein which will eventually drain into the right, middle or left hepatic vein which eventually drains in the ascending IVC.
What is the billiary system?
Organs that synthesise, store and secrete bile.
What are the main componenets of bile?
Bilirubin
Biliverdin
Products of rbc breakdown
This gives bile its green colour
What vessels does bile drain into when leaving the liver?
Bile canaliculi
Right/left hepatic ducts
Common hepatic ducts
How does bile enter the gallbladder?
The common hepatic duct branches into the cystic duct.
How does bile enter the duodenum?
By the common bile duct
This is made from the combining of the common hepatic duct and the cystic duct.
This will combine with the pancreatic duct to form the ampulla a vatar which enters the duodenum at the major duodenal papilla.
What sphincter control the flow of bile into the duodenum?
Sphincter of the bile duct - at the start of the common bile duct, allows bile to flow from the common hepatic duct into the cystic duct
Pancreatic sphincter - controls release of pancreatic juices
Sphincter of oddi - release into duodenum
What comonly blocks bile flow?
Bile stones
pancreatic tumour
What is billiary colic?
When blockage of the passage of bile out of the gall bladder, gall bladder contracts painfully to try and get bile past the blockage.
Often causes pain after eating.
What is cholecsystitis?
When the gallbladder becomes inflammed and sore because the passage of bile into the duodenum is blocked.
What causes jaundice?
Blocked flow of bile from the liver
Increased levels of bilirubin
What are the consequences if bile can not mix with the food?
Fat is not digested
Stools are greasy and pale
More acidic contents of the intestines - as not neutralised
What is pancreatis?
When digestive enzymes are unable to leave the pancreatic duct, so begin the digest the pancreas itself, resulting in pain and inflammation
What is the general location of the pancreas?
L1 or transpyloric plane level
retroperitoneal - except the tail
Epigastrum and left hypochondriac regions
How does the position of the pancrea relate to the stomach?
Stomach is anterior, seperated by the lesser sac
How is the position of the pancreas related to the duodenum?
C-shpaed part of duodenum curves around the pancreas head
How is the position of the transverse mesocolon realted to pancreas?
transverse mesocolon fused with the anterior surface of the pancreas
How does the position of the common bile duct relate to the pancreas?
Common bile duct descends just behind the head of the pancreas before joing the major pacnreatic duct through the major duodenal papilla
How is the position of the spleen related to the position of the pancreas?
Tail of the pancreas is anterior and medial to the spleen
Connected by the lienorenal ligament
How is key vasculature orientated around the pancreas?
IVC and AA are posterior to the head of the pancreas
SMA is posterior to the neck of the pancreas
The splenic vein and SMV unite to form the hepatic portal vein posterior to the neck of the pancrease
The splenic artery travels along the superior border ot the pancreas.
How is the pancreas divided into different segments?
Tail - near hilum of spleen
body - until duodenum surrounds pancreas
Neck - where the duodenum originally makes contact with the pancreas
Head- within the C-shape curve of the duodenum
Ucinate process - the terminal part of the pencreas, inferior to the neck
What is the arterial supply of the pancreas?
Pancreatic branches from the splenic artery
THe superiorpancreaticoduodenal from the gastroduodenal
The inferior pancreaticoduodenal from the SMA
Both of which have anterior and posterior branches
What is the venous drainage of the pancreas?
Into the superior mesenteric branches of the hepatic portal vein
This rest of the pancreatic venous branches are from the splenic vein
What lymphatic vessels drain the pancreas?
Follow the arterial supply
Empty into pancreaticosplenal nodes and the pyloric nodes
Which then empty into the superior mesenteric and the coeliac lymph nodes.
Draw a diagram to represent the bile tree structures
Draw a diagram to represent the sphincters in the bile tree
What are the boundaries of the caudate lobe?
The left lobe indentation for the ligamentum venosum and the IVC
What are the boundaries of the quadrate lobe?
The left lobe indentation for the ligamentum teres and the gall bladder.
How do the ligaments of the liver relate to the foetal blood supply?
The ligamentum venosum (posterior) is a remanant of the ducuts venosus
The ligamentum teres or the round ligament of the liver - is a remanant of the umbilical veins
What are the different impressions on the visceral surface of the liver and where can they be found?
The right lobe - the renal impression and the colic impression
The left lobe - the gastric impressions
The impression for the vena cava - prominent and central on the posterior surface, anterior of the visceral sruface
How many hepatic veins drain directly into the inferior vena cava?
3 - left, right and intermediate
What structure is in direct contact with the bare area of the liver?
The diaphragm
What are the surface marking of the liver?
The fitfh intercostal space on the left midclavicular line
The fifth intercostal space on the right midclvavicular line
Midline at the transpyloric plane
Tip of the eights costal cartilage on the right
The lowest point of the costal margin on the right
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How can you describe the boundaries of the liver using the ribs?
Right - between ribs five and rib ten
Left - rib five and lower border passess over the costal cartilage of rib seven
What two veins unite to form the hepatic portal vein?
The splenic and the superior mesenteric vein
What two vessels unify to form the common bile duct?
The cystic duct and the common hepatic duct
The liver forms eight functional segments, what differentiates these eight different segments?
Individual branch of the portal triad (portal vein, hepatic artery and the bile duct)
How are bilirubin and bile related?
Bilirubin is a component of bile
Is the pancrease intra or retro peritoneal?
Retroperitoneal expect from the tail which is intraperitoneal
Pancreatic cancer is very aggressive, suggest some reasons why?
Retroperitoneal - difficult to palplate/image so slow to diagnose
Quick to metastasise - rapidly into the liver or the duodenum by the pnacreatic duct and billary tree.
What blood vessel supplying the pancreas has anterior and posterior branches?
The inferior pancreaticoduodenal from the SMA
The superior pancreaticoduodenal from the gastroduodenal
What is the portal hepatus?
The hilum of the liver where the portal triad enter
What does the uncinate part of the pancreas surround?
The superior mesenteric vessels
Where are the portosystemic anastamoses found?
Why are these important clincally?
Umbilical vein - round ligament of liver, is re canalised and connects the vein in the anterior abdominal wall, veins appear in a radial pattern around the umbilicus
Oesophagus - anatamoses between systemic and hepatic circulation. Internal veins become variococed, swallow so black poo or cough up red blood
Superior rectal artery - variococity
Identify signs of hepatic hypertension
What are all the branches from the hepatic portal vein?
The left and right gastric veins
The superior mesenteric vein
The spleninc vein (drained into by the inferior mesenteric vein)
What is hepatic portal hypertension?
Causes/
Cause within liver
Cirrhosis - fibrosis of connective tissue, stiffer so more difficult for blood to flow through, backflow creates hypertension
Hepatitis - inflammation, impedes blood flow through the liver.
What is pre hepatic portal hypertension?
Causes?
Thrombus in veins that drain into hepatic portal vein
Tumour in the GIT that push on the veins into the portal vein
What is post hepatic portal hypertension?
Causes?
Slows down flow of blood from IVC from the liver
Examples include heart failure
What is the consequences of portal hypertension?
Increases resistance in the liver
More difficult for blood to drain into the liver.
Why might the abdomen be distended in a patient with hepatic hypertension?
Back flow of blood in the vessels that supply the hepatic portal vein
Accumulation of ECF around the vessels
Describe two routes of venous drainage from the umbilicus, one into systemic circulation one into portal circulation
para-umbilical veins - direct tributary into the portal vein
Epigastric vein - pubic and obturator branch of the inferior epigastric vein, will drain into the external iliac and into the IVC via the common iliac.
