9. Abdomen III Flashcards
What are the 6 functions of the liver?
- storage,metabolism and release of nutrients and some vitamins
- detoxification and elimination of toxins, drugs and metabolites
- synthesis of proteins : albumin and clotting factors
- synthesis and secretion of bile, important for lipid digestion and absorption
- role in immune function and clearance of intestinally absorbed bacteria
- removal of red blood cells
What is the blood flow rate to the liver?
- 1.5L/min
What ribs is the liver protected by?
- 7-11
What areas of the abdomen does the liver occupy?
- Starts in the right hypochondrium and extends to the epigastrium
What surface of the liver is not covered in peritoneum?
- superior surface
Is the liver retro or intraperitoneal?
- intraperitoneal
What are the 4 anatomical lobes of the liver?
- Left lobe
- Right lobe
- Caudate lobe
- Quadrate lobe
Why is the liver intraperitoneal?
- develops in the ventral mesogastrium
What are the two surfaces of the liver?
- diaphragmatic
- visceral
How many functional segments of the liver are there?
- 8
Label this diagram
What structure is the quadrate lobe close to?
- gallbladder
What lobe does the quadrate lobe work with functionally?
- the left lobe
What happens if you remove one of the segments of the liver and why?
- nothing
- Each segment (8) has its own individual blood supply
- so if one segment is removed it wonโt affect the other segments
What is the falciform ligament?
- double fold of peritoneum connecting the liver to the anterior abdominal wall
What divides the left lobe from the right lobe?
- falciform ligament
Label this diagram
What is the porta hepatis equivalent to?
- the hilum of the lung
What is the thickening on the free edge of the falciform ligament?
- round ligament (ligamentum teres)
What is the ligamentum teres?
- embryological remnant of the umbilical vein (brings oxygenated blood from the placenta)
How is bile transported to the duodenum?
- via the common bile duct
Where does the common bile duct receive bile from?
- the common bile duct receives bile from the cystic duct which comes from the gallbladder
- or it receives bile directly from the liver through the common hepatic duct
What 2 structures come together to form the common hepatic duct?
- The right and left hepatic duct come together and form the common hepatic duct
What structures come together to form the common bile duct?
- cystic duct will join the common hepatic duct to create the common bile duct
What does the proper hepatic artery divide into?
- divides into the right hepatic and left hepatic artery
Where is the portal triad?
- runs though the free edge of the lesser omentum
What is the lesser omentum?
- double fold of peritoneum that attaches the liver to the stomach
What is โPringleโs manoeuvre?
- hemostat is used to clamp the hepatoduodenal ligament (free border of the lesser omentum)
- interrupting the flow of blood through the hepatic artery and the portal vein
What are the 5 structures that are contained in the porta hepatis?
- common bile duct
- left and right hepatic duct
- cystic duct
- hepatic portal vein
- hepatic artery
Label this image
Label this image
What is the round ligament?
- thickening of the falciform ligament
Label this image
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What happens to the falciform ligament as it ascends?
- it ascends and splits into two layers so one layer goes to the right and the other goes to the left because the falciform ligament is made of 2 layers
What is the falciform ligament called when it splits?
- coronary ligament of the liver
What does the top surface of the coronary ligament attach to?
- top surface attaches to the bottom of the diaphragm
What do the coronary ligaments fuse to become?
- fuse and become the triangular ligament (left and right)
Label this image
Why does the bare area occur?
- liver undergoes a really accelerated growth within vental mesogastrium so the two layers of peritoneum separate apart (like hulk and his clothes)
What are the boundaries of the bare area?
- anterior and posterior coronary ligaments
Why is the bare area clinically important?
- bare area of the liver is clinically important because of the portacaval anastomosis and it represents a site where infection can spread from the abdominal cavity to the thoracic cavity
What is the subphrenic space?
- gap between the liver and diaphragm
What is the clinical significance of the peritoneal recesses of the liver?
- the liver recesses are areas where fluid can fill if there is an infection
What is the pouch of Morrison?
- gap between the liver and the kidney
- hepatorenal pouch (of Morrison)
What is the subhepatic space?
- space is between the inferior surface of the liver and the kidney
Label this image
Label this image with :
pouch of morrison
subphrenic space
right subhepatic space
What does the gastric artery supply and where does it go?
- left and right go inbetween the lesser omentum to supply the stomach
Label this image
Label 1 and 2
- 1) hepatogastric ligament
- 2) hepatoduodenal ligament
Where does the portal triad run?
- free edge of lesser omentum
What are the superior, inferior, posterior and anterior borders of the lesser sac?
- superior : caudate process of liver
- inferior : 1st part of duodenum
- posterior : inferior vena cava and right crus of diaphragm
- anterior : portal triad (in free edge of lesser omentum)
How many vessels is the liver supplied by?
- two
What vessels make up the livers dual supply?
- 25% is from the hepatic artery proper
- 75% of the blood comes from the GI tract through the hepatic portal vein
Where is blood processed?
- blood is processed in the sinusoids
What veins unite to form the hepatic portal vein? Draw a schematic below.
- three main vessels:
- the gastric, pancreaticomesenteric, and lienomesenteric veins
After blood is processed in the sinusoids of the liver what happens?
- sinusoids collect into the central vein and unite into the three hepatic veins and the hepatic veins join directly into the IVC
What brings blood to the liver from the midgut?
- superior mesenteric vein brings blood from the midgut
Where does the inferior mesenteric vein bring blood from?
- hindgut
Label this image
1) hepatic portal vein
2) superior mesenteric vein
3) splenic vein
4) inferior mesenteric vein
How does portal hypertension arise?
- When scarring and fibrosis from cirrhosis obstruct the portal vein in the liver
- pressure rises in the portal vein and its tributaries producing portal hypertension
Why can the spleen become enlarged with cirrhosis?
- The splenic vein enters directly into the hepatic portal vein
- If the vessel is blocked and blood canโt flow out of the spleen, it will continue to grow and you get splenomegaly
What are portosystemic anastomoses?
- blood can flow into the portal system or straight into the systemic venous circulation so it is not processed by the liver
What are the oseophageal portal and systemic veins?
- portal via left gastric
- systemic via azygos vein
What are the anal portal and systemic veins?
- portal via inferior mesenteric veins
- systemic via inferior and middle rectal veins
What are the portal and systemic peri-umbilical veins?
- portal via paraumbilical veins
- systemic via epigastric veins
What is caput medusae?
- If the portal system is blocked and blood canโt flow through the paraumbilical veins
- the majority of the blood will travel via the epigastric veins, (like a traffic jam)
- so more blood is flowing through them and they become more dilated
How does the biliary system develop?
- as an outgrowth of the foregut
Where is bile produced and where does it go?
- Bile is produced in the liver and travels through the right or left hepatic duct to enter the common hepatic duct
Label this image
Where is the gallbladder located?
- behind the tip of the right 9th costal cartilage, where the lateral margin of rectus abdominis crosses the costal margin
What are the 2 routes bile can take once it reaches the common hepatic duct?
- can travel through the cystic duct to be stored in the gallbladder
- or it can travel down the common bile duct to fuse with the main pancreatic duct to form the hepatopancreatic ampulla of vater
Where does the ampulla of vater open into?
- major duodenal papilla which enters into the lumen of the duodenum
What is the release of bile controlled by?
- spiral folds