Abdomen 2 - Liver Flashcards
What are the endocrine and exocrine functions of the liver?
endocrine = secreting hormones into the bloodstream
exocrine = producing bile; secreted into the biliary system, helps digest fats
What are the two main sources of blood to the liver and what are their characteristics?
proper hepatic artery
- delivers oxygenated blood to nourish liver tissue
hepatic portal vein
- delivers deoxygenated, nutrient-rich blood from the GI tract for filtration and processing
How does blood exit the liver?
through the left and right hepatic veins - drain into IVC
What is the falciform ligament and what does it contain?
- peritoneal fold that connects the liver to the anterior abdominal wall and diaphragm
- divides diaphragmatic surface of liver into left & right lobes
- contains round ligament (ligamentum teres) = remnant of the umbilical vein
What are the four anatomical lobes on the visceral surface of the liver?
right
left
caudate (posterior)
quadrate (anteroinferior)
What is the porta hepatis and what does it transmit?
porta hepatis = transverse fissure on the liver’s visceral surface; gateway for the portal triad:
- hepatic artery proper
- hepatic portal vein
- bile ducts
- lymphatics and autonomic nerves
What structure forms the “H” shape on the visceral liver surface?
two sagittal fissures and the transverse porta hepatis fissure
- together define lobar boundaries but not functional segments
What is the course of arterial blood supply to the liver?
Coeliac trunk → common hepatic artery → proper hepatic artery → right and left hepatic arteries
right hepatic artery gives rise to the cystic artery = supplies gallbladder
How does venous blood reach the liver for filtration?
via hepatic portal vein
- formed by splenic & superior mesenteric veins merging (splenic vein may receive contributions from the IMV)
- blood is nutrient-rich but deoxygenated = for filtering
How is the liver functionally segmented?
left and right hemi-livers (not based on anatomical lobes)
- further into 8 segments
- each segment has its own vascular and biliary supply = allows for independent surgical resection
What structures make up the interlobular portal triad in each liver lobule?
branch of the portal vein
branch of the hepatic artery
a bile duct
allow for nutrient processing, detoxification, and bile drainage within each lobule
What is the flow direction of blood and bile in liver lobules?
blood from the hepatic artery and portal vein flows inward through sinusoids toward the central vein
bile flows outward from hepatocytes through bile canaliculi toward bile ducts
What are Kupffer cells and their role in liver function?
specialised macrophages in liver sinusoids
- phagocytose bacteria, debris, and old red blood cells
- important in immune defence
What are the main functions of the gallbladder and biliary ducts?
biliary duct transport bile from the liver to the duodenum for fat digestion
- gallbladder stores and concentrates this bile
- when food enters the duodenum, bile is released to emulsify fats
What is bile and what is its primary role in digestion?
bile = greenish fluid produced by the liver
- emulsifies dietary fats in the small intestine = breaks them them into smaller droplets
Describe the structure of the biliary tree from the liver to the duodenum
Left and right hepatic ducts drain bile from the liver’s hemi-lobes.
These merge to form the common hepatic duct.
The cystic duct from the gallbladder joins this to form the bile duct (common bile duct).
The bile duct descends to join the main pancreatic duct before emptying into the duodenum at the major duodenal papilla.
What happens to bile when it is not needed for digestion?
flows retrogradely via the cystic duct into the gallbladder - stored & concentrated
Describe the location and attachment of the gallbladder.
gallbladder lies in a fossa on the liver’s visceral surface and is attached via connective tissue
- contacts the liver, duodenum, and transverse colon
What are the anatomical regions of the gallbladder?
Fundus: Rounded tip, projects past the inferior liver border.
Body: Central part, lies against liver and intestines.
Infundibulum: Funnel-like part leading to the neck.
Neck: S-shaped bend that connects to the cystic duct.
What is the function of the spiral fold in the cystic duct?
helps maintain duct patency and regulates bile flow - not a true valve
What is the arterial supply of the gallbladder?
cystic artery - branch of the right hepatic artery
(coeliac trunk > common hepatic > proper hepatic > right hepatic > cystic artery)
What is the cystohepatic (Calot’s) triangle and its significance?
triangle formed by the common hepatic duct, cystic duct, and liver margin - the cystic artery and sometimes the right hepatic artery
must be clearly identified during cholecystectomy to avoid damaging vital vessels
How is venous blood drained from the gallbladder?
neck & cystic duct - cystic veins > hepatic portal vein
fundus & body - directly into liver’s visceral surface
What causes gallstones and what are their effects?
gallstones form when bile becomes overly concentrated, typically due to excess bile salts, cholesterol, or bilirubin
- cholecystitis
- inflammation of the gallbladder, often due to obstruction by gallstones, leading to bile build-up, swelling, and pain - intestinal obstruction
- repeated inflammation causing the gallbladder to adhere to the duodenum, forming a fistula
- gallstones may pass through this into the intestines, potentially lodging at the ileocecal junction, causing bowel obstruction
