Pancreas and Liver Flashcards
What are the exocrine functions of the liver and pancreas?
Accessory organs for intestines, provide excretions directly into small intestine lumen
What are the endocrine functions of the liver and pancreas?
Regulate blood borne energy substrate availability
Where are the digestive pro-enzymes secreted?
From the pancreatic duct to the 2nd part of duodenum
What is the position of the pancreas?
Retroperitoneal, close to major blood vessels
Where is the sphincter of Oddi?
Where the gall bladder meets the duodenum
Where does the pancreas’ hepatic portal vein form?
At the L1 region, behind the neck region of the pancreas
From what three arteries does blood enter the pancreas?
Ant and post superior pancreatico-duodenal arteries
Inferior pancreatico-duodenal artery
Splenic artery
What are the primary functions of the exocrine pancreas?
Neutralise acid
Deliver enzymes for macronutrient digestion in duodenum
What are acinar cells?
Main secretory cells
Clusters are connected by intercalated ducts
Converge on collecting duct
Lining cells add ions and secretions
What is exocrine pancrease regulation dependent on?
Phase of digestion
Describe the cephalic phase of digestion?
Vagus nerves stimulates pancreatic secretions by releasing ACh and VIP
Describe the gastric phase of digestion?
Medicated by vagovagal reflexes
Account for =10% of pancreatic secretions
Describe the intestinal phase of digestion?
Controlled hormonally by secretin and CCK
Accounts for majority of pancreatic secretions =65%
What is CCK?
Plays a role of digestion of proteins and fats
What houses inactive digestive enzymes in acinar cells?
Zymogen granules
What causes the secretion of zymogen granules?
CCK, VIP and gastric releasing peptides
What happens when zymogen granules are activated?
They are exocytosed from acinar cells into the luminal space
What do acinar cells secrete?
Enzymes, sodium, potassium, chlorine and HCO3-
What do ductal cells secrete?
Serous and HCO3-
In acinar cells what do basolateral CCK and ACh binding stimulate?
Chlorine ion transport across the apical membrane
What can acinar cells also facilitate?
Paracellular sodium and water movement
What are the functions of intercalated ductal cells?
Secretin and ACh bind in ductal cells
Activates cystic fibrosis transmembrane conductance regulators
Transporters recycle Cl- and HCO3-
With an increase in flow rate from the pancreas, what happens to the ion concentration?
HCO3- increases
Cl- Decreases
Na+ and K+ unaffected
Describe the location of the liver
Lies across upper abdomen, under diaphragm, surrounded by peritoneum
What is the liver surrounded by?
Glisson’s capsule- thin connective tissue layer with extensions into the organ between the lobules
What vein provides absorbed nutrients to the liver from the stomach and gut?
Hepatic portal vein
What supplies the hepatocytes with oxygen?
Hepatic artery
Where is the bile drained by?
Canaliculi, lies between the hepatocytes into bile ductules and eventually into bile ducts
What vein drains the liver?
Hepatic veins, feeds into the inferior vena cava
What separates the left and right lobes of liver?
Falciform ligament
What lobe lies next to the gall bladder?
Quadrate lobe
What is the area of the liver called that is contact with the diaphragm?
The bare area, no peritoneal covering
What are the functions of the liver?
Synthesis and secretion of bile, storage of glucose, glycogegn, proteins, vitamins and fats, detoxification, synthesis of blood clotting
What are the constituents of bile?
Bilirubin (bile pigments), cholesterol, phopholipids, fatty acids, water and electrolytes
Where are bile pigments derived from?
The breakdown products of haemoglobin
What are bile salts?
Responsible for the detergent and emulsifying effect on bile on fats
Describe the circulation of the hepatobiliary system
Liver produces and secretes bile, hepatocytes secrete bile into canaliculi, across bile ducts, the bile flow from hepatocytes is in opposite direction of blood from hepatic artery
What controls the movement of bile into the duodenum or gall bladder?
Sphincter of Oddi
What happens when the Sphincter of Oddi relaxes and contacts?
Con- gall bladder
Rel- duodenum
What regulates SOO contraction?
CCK
What stores and distributes bile?
Gallbladder
What happens when the gall bladder contracts?
Expels bile in response to CCK
What hormones inhibit bile acid secretion?
Somatostatin and noradrenaline
What are some non-biliary liver functions?
Metabolism of CHO, protein fat
Detoxification, removal of ammonia and ethanol
Immune system function
