liver and hepatobiliary tract Flashcards
Where is the liver located in the body?
The liver is mainly in the right upper quadrant, protected by the ribcage and diaphragm.
Which ribs does the liver lie deep to?
The liver lies deep to ribs 7-11 on the right side.
Does the liver extend beyond the right upper quadrant?
Yes, it extends across the epigastrium into the left upper quadrant, including part of the left hypochondrium.
Can the liver be palpated?
Yes, the inferior margin of the liver is usually palpable at the margin of the ribs.
Which organs are located near the liver?
The liver is near the stomach, spleen, pancreas, kidneys, intestines, and colon.
What is the function of the biliary tract?
It conveys bile from the liver to the duodenum for digestion.
Where is bile produced and stored?
Produced in the liver and stored/concentrated in the gallbladder.
When does the gallbladder release bile?
Intermittently, when fat enters the duodenum.
Where is the gallbladder located?
At the intersection of the mid-clavicular line and the inferior border of the right 9th rib.
Where does the gallbladder lie on the liver?
In the gallbladder fossa on the visceral surface of the liver.
How does the gallbladder relate to the duodenum?
The body and neck of the gallbladder lie anterior and superior to the superior part of the duodenum.
how is the pancreas oriented in the body?
It is an elongated organ oriented transversely in the right and left upper quadrants, mainly in the epigastric region.
At which vertebral levels is the pancreas located?
Body: Crosses the midline at L1/L2.
Head: Directed to the right, extending to L2/L3.
Tail: Related to the spleen.
Where is the pancreas located in relation to other organs?
Posterior to the stomach.
Between the duodenum (right) and spleen (left).
Is the pancreas a retroperitoneal organ?
Yes, it is a secondary retroperitoneal organ.
What are the main functions of the liver?
Metabolism: Breakdown of toxins and regulation of blood glucose.
Digestion: Secretes bile to aid in fat emulsification.
What are the four lobes of the liver?
Right lobe
Left lobe
Caudate lobe (posterior, part of the right lobe)
Quadrate lobe (posterior, part of the right lobe)
What does the falciform ligament do?
Separates the right and left lobes and connects the liver to the anterior abdominal wall.
What is the ligamentum teres?
A remnant of the umbilical vein, forming the inferior free border of the falciform ligament.
What structures are visible on the posterior side of the liver?
Caudate lobe
Quadrate lobe
Groove for the inferior vena cava (IVC)
What covers the liver’s diaphragmatic surface?
Visceral peritoneum, except for the bare area, which is in direct contact with the diaphragm.
What is the bare area of the liver?
A region on the posterior liver that is not covered by peritoneum and is in direct contact with the diaphragm.
What is the coronary ligament?
A peritoneal reflection that demarcates the bare area,
consisting of:
Upper (anterior) layer
Lower (posterior) layer
How are the triangular ligaments formed?
The right and left triangular ligaments are formed where the coronary ligament layers meet.
What is the function of the falciform ligament?
It connects the liver to the anterior abdominal wall and separates the right and left lobes.
label the peritoneal coverings of liver
label this alternative view of the peritoneal coverings of liver
Where is the liver located in relation to other organs?
Anterior to the stomach and duodenum.
Right lobe is related to the right kidney and right colic (hepatic) flexure.
Why does the liver’s position change with respiration?
It is attached to the inferior surface of the diaphragm, so it moves with breathing.
What are the 4 key impressions on the liver?
Gastric impression (for stomach)
Duodenal impression
Renal impression (for right kidney)
Colic impression (for right colic flexure)
label the 4 key impressions of the liver
What is the porta hepatis?
The hilum of the liver, where vessels, nerves, and hepatic ducts enter and leave the liver.
What is the function of the lesser omentum?
It extends from the porta hepatis to the lesser curvature of the stomach and first part of the duodenum.
What is enclosed within the hepatoduodenal ligament?
The portal triad
what does the portal triad consist of
Common bile duct
Hepatic artery proper
Hepatic portal vein
What is the epiploic foramen?
The opening that connects the greater and lesser sacs of the peritoneal cavity.
What is the hepatic artery proper?
A continuation of the common hepatic artery after giving off the gastroduodenal artery.
Where does the common hepatic artery come from?
It is a branch of the coeliac trunk.
What happens to the hepatic artery proper after entering the porta hepatis?
It divides into right and left branches to supply the right and left lobes of the liver.
What artery does the common hepatic artery give off before becoming the hepatic artery proper?
The gastroduodenal artery.
What are the two main sources of blood supply to the liver?
Hepatic portal vein (75-80%) – carries nutrient-rich blood.
Hepatic artery proper (20-25%) – carries oxygen-rich blood.
How does the oxygen content in portal blood compare to systemic circulation?
Portal blood has 40% more oxygen than venous blood in the systemic circulation.
What does the hepatic artery proper primarily supply?
It mainly supplies the intrahepatic bile ducts.
How is blood drained from the hepatocytes?
- Sinusoids drain into the central vein.
- Central veins lead to hepatic veins.
- Hepatic veins drain into the IVC (inferior vena cava).
What are portosystemic anastomoses?
Collateral pathways between the portal vein and systemic venous system, allowing blood to bypass the liver in cases of portal hypertension.
Why are portosystemic anastomoses clinically significant?
They help divert blood when portal venous flow is obstructed, preventing complications like portal hypertension.
What are 3 key locations of portosystemic anastomoses?
What happens to blood flow in portal hypertension?
Blood is diverted away from the liver through portosystemic anastomoses, leading to varices.
What is portal hypertension?
Increased pressure in the hepatic portal vein due to liver cirrhosis or obstruction, causing blood to be diverted away from the liver.
How does portal hypertension lead to varicose veins?
The high pressure forces blood to bypass the liver through portosystemic anastomoses, enlarging the veins.
What are esophageal varices and why are they dangerous?
Enlarged veins in the esophageal wall due to portal hypertension.
Risk of rupture and severe hemorrhage.
How does portal hypertension cause hemorrhoids?
Blood is diverted from the inferior mesenteric vein into rectal veins, enlarging venous plexuses in the rectum and anal canal.
Are all hemorrhoids linked to portal hypertension?
No, not all hemorrhoids are caused by portal hypertension.
What is portal hypertension?
Increased pressure in the hepatic portal vein due to obstruction, often caused by liver cirrhosis.
How does portal hypertension affect blood circulation?
It diverts blood away from the liver, leading to varicose veins in alternate venous pathways.
What is caput medusae?
A sign of severe portal hypertension.
Varicose periumbilical veins form a snake-like pattern around the umbilicus, resembling Medusa’s head.
What ducts drain bile from the liver?
The right and left hepatic ducts drain bile from the right and left lobes of the liver.
How is the common bile duct formed?
The right and left hepatic ducts unite to form the common hepatic duct.
The common hepatic duct joins the cystic duct (from the gallbladder), forming the common bile duct.
What is the hepatopancreatic ampulla?
A dilation formed by the joining of the common bile duct and main pancreatic duct before entering the duodenum.
Where does bile enter the duodenum?
Through the major duodenal papilla, located in the second part of the duodenum.
Where is the gallbladder located?
It lies in the gallbladder fossa on the visceral surface of the liver.
What are the 3 main parts of the gallbladder?
Fundus
Body
Neck – connects to the cystic duct.
What does the cystic duct connect?
It connects the neck of the gallbladder to the common hepatic duct, forming the common bile duct.
What artery supplies the gallbladder?
The cystic artery, which usually arises from the right hepatic artery.
Are there variations in the cystic artery?
Yes, variations in its origin and course are common.
What are the two main functions of the pancreas?
Exocrine function – Secretes pancreatic juice into the duodenum for digestion.
Endocrine function – Produces insulin and glucagon to regulate blood sugar.
What are the 5 main parts of the pancreas?
- Head – Located in the C-shaped curve of the duodenum.
- Neck – Between the head and body.
- Body – Extends across the midline.
- Tail – Closely related to the spleen.
- Uncinate process – A projection of the head that lies posterior to the superior mesenteric vessels.
What are the two pancreatic ducts and where do they drain?
Main pancreatic duct – Joins the common bile duct and opens at the major duodenal papilla.
Accessory pancreatic duct – Opens into the duodenum at the minor duodenal papilla.
Which 3 arteries supply the pancreas?
Splenic artery (branch of the coeliac trunk)
Superior pancreaticoduodenal arteries (from the coeliac trunk)
Inferior pancreaticoduodenal arteries (from the superior mesenteric artery (SMA))
Why does the pancreas receive blood from both the coeliac trunk and SMA?
Because it is derived from both the foregut and midgut.
Where does the venous drainage of the pancreas occur?
Pancreatic veins drain into either the splenic vein or the superior mesenteric vein (SMV).
What is the significance of the pancreaticoduodenal arteries?
They form an anastomotic network between the coeliac trunk and SMA, ensuring collateral blood flow.
What are gallstones?
Solid masses in the gallbladder, cystic duct, or bile duct, composed mainly of cholesterol crystals.
Can gallstones be asymptomatic?
Yes, but larger gallstones can injure the gallbladder or obstruct the biliary tract.
Where do gallstones commonly get stuck?
The distal end of the common bile duct, causing pain.
What are two complications caused by obstructed gallstones?
Cholecystitis – Inflammation of the gallbladder.
Pancreatitis – Inflammation of the pancreas.
