Pancreas and Liver Flashcards
What is the exocrine function for the pancreas and liver?
They are accessory organs for intestines
What do the pancreas and liver provide to the intestines?
Provide excretion (digestive enzymes, HCO3-) directly into intestine lumen to digest carbohydrates, proteins and lipids
What is the endocrine function of the pancreas and liver?
Regulate blood borne energy substrate availability via hormones
Therefore after absorption
Where do the digestive pro-enzymes enter the small intestines?
Enter from the pancreatic duct to the 2nd part of the duodenum
Where does the pancreas sit?
Behind the retroperitoneal lining
Sits in a c-shape curve of the duodenum
What allows secretion into the duodenum from the gall bladder and pancreas?
Sphincter of Oddi
Where does the portal vein form?
Behind the neck of the pancreas at L1
What is the blood supply of the pancreas?
Splenic artery
Anterior and posterior superior pancreatico-duodenal arteries
Anterior and posterior inferior pancreatico-duodenal arteries
What is the origin of the splenic artery?
Coeliac trunk
What is the origin of the pancreatico-duodenal arteries?
Superior mesenteric artery
Coeliac trunk
What are the primary functions of the exocrine pancreas?
Neutralise the very acidic bolus that has arrived from the stomach
Deliver enzymes for macronutrient digestion in duodenum
What are pancreatic acinar cells?
Main secretory cells in pancreas
What connect clusters of acinar cells?
Intercalated ducts
Where do intercalating ducts flow into?
Intralobular ducts
What do acinar cells secrete?
Sodium, potassium, chlorine and bicarbonate
What do ductal cells secrete?
Serous and bicarbonate
What is the cephalic phase accountable for in regards to pancreatic secretions?
25%
What is the gastric phase accountable for in regards to pancreatic secretions?
10%
What is the intestinal phase accountable for in regards to pancreatic secretions?
65%
What is the gastric phase of digestion controlled by?
Vagovagal reflexes
What controls the intestinal phase of digestion?
Secretin and CCK
What controls the cephalic phase of digestion?
Vagus nerve stimulates pancreatic secretions by releasing ACh and VIP
What granules in the acinar cells house digestive enzymes?
Zymogen granules
What are digestive enzymes released to?
In response to CCK, VIP and gastric-releasing peptide
What happens when CCK enters the blood stream?
They travel to pancreatic acinar cells and bind to CCK receptors
These then force the zymogen granules to be exocytose and release the digestive enzymes into the intestinal space
How do acinar cells secrete chlorine and what does this allow?
Basolateral binding of CCK and ACh stimulates chlorine across the apical membrane
This then facilitates the paracellular water and sodium movement
How do intercalated ductal cells secrete chlorine and bicarbonate?
Secretin and ACh bind in ductal cells
These activate cystic fibrosis transmembrane conductance regulators, chlorine channels and chlorine-bicarbonate co-transporters
What can flow rate change in pancreatic secretion rate?
Increased in flow rate will increase the concentration of bicarbonate but will decrease chlorine
What does flow rate no effect?
Sodium and potassium
What surrounds the liver?
Peritoneum apart from the bare area
What completely surrounds the liver?
Glisson’s capsule
What is the Glisson’s capsule?
Thin connective tissue later with extensions into the organ between the lobules
What is the blood supply of the liver?
Hepatic portal vein and hepatic artery
Function of the hepatic portal vein?
Bringing absorbed nutrients from the stomach and gut to the liver
Function of the hepatic artery?
Supplies the hepatocytes with oxygen
What are the different lobes of the liver?
Left
Right
Caudate
Quadrate
Spigelian
What separates the left and right lobes?
Falciform ligament
What are the main functions of the live?
Synthesis and secretion of bile
Storage of glucose, glycogen, proteins, vitamins and fats
Detoxification of metabolic waste
Synthesis of blood clotting and anticoagulant factors
What is bile made from?
Bile pigments
Cholesterol
Phospholipids
Fatty acids
Water
Electrolytes
What is the main bile pigment?
Bilirubin
What is bilirubin?
An orange-yellow pigment formed in the liver by the breakdown of haemoglobin
What are the role of bile salts?
Detergent and emulsifying effect of bile on fats
What do hepatocytes do?
Secrete bile into canaliculi across a series of bile ducts until they from the common hepatic duct
What is the flow of bile in relation to the hepatic artery and vein?
The opposite
Where can bile travel from?
From the common bile duct into the duodenum or into the gall bladder
What decides the end point of bile?
Sphincter of Oddi
When relaxed, mainly to duodenum
When contracted to gall bladder
What is the effect of bile acids in bile?
Emulsify lipids
What is the effect of water and electrolytes in the bile?
Water is reabsorbed by the changes in isosmotic pressure to concentrate the bile
What regulates the sphincter of Oddi?
CCK
What is the effect of CCK on the gall bladder?
Expel bile
What is the effect of vagal stimulation on the gall bladder?
Weak contraction
What inhibits bile acid secretion?
Somatostatin and noradrenaline
What processes does the liver do in regards to metabolism?
Glycogenolysis
Gluconeogenesis
What does the liver detoxify?
Removal of ammonia and ethanol and drug biotransformation
What is the immune function of the liver?
Removal of intestinal bacteria from portal blood
