Topic 54 - The exocrine function of the pancreas, pancreas enzymes, regulation of pancreatic juice secretion Flashcards
Words to include in the exocrine function of the pancreas
- Gastric content
- Neutralize
- Pancreatic juice
- Acinar cells
- Zymogen granules
- Tubules
- HCO3- (bicarbonate)
- Interlobular duct
- Extralobular duct
- Main collecting tubule
- Pancreatic duct
- Dudoenum
Words to include in pancreas enzymes
- Enzymes
- α-amylase
- Lipase
- Esterase
- Nuclease
- Inactive proenzymes:
- Trypsinogen
- Chymotrypsinogen
- Proelastase
- Procarboxypeptidase
- Prophospholipase
- Lumen of ileum
- Enteropeptidase
- Trypsin
- Trypsinogen
Words to include in regulation of pancreatic juice
- Secretory activity
- Hormoes
- Neurotransmitters
- Parasympathetic
- N. vagus
- Sympathetic
- N. sphlanchnicus
- Cephalic phase
- Protein
- Juice
- Gastric phase
- Parasympathetic effect
- Gastrin
- Enzyme secretion
- Interstitial phase
- Secretin
- Amino acids
- Fatty acids
- Monoglycerides
- Pancreatic juice secretion
- CCK
Topics to include in the essay
- The exocrine function of the pancreas
- Role of the function
- Pancreatic juice
- Acinar cells
- Pancreas enzymes
- Enzymes
- Proenzymes
- Activation of proenzymes
- Regulation of pancreatic juice secretion
- Hormones and neurotransmitters
- Parasymp. and symp.
- Cephalic phase
- Gastric phase
- Interstitial phase
The exocrine function of the pancreas
Role of the pancreas
- The exocrine function of the pancreas is producing the pancreatic juice
- It has two main roles:
- Neutralize acidic gastric content getting into the duodenum
- Secretes enzymes essential for digestion of proteins, fats and carbohydrates
The exocrine function of the pancreas
Pancreatic juice secretion
- Exocrine cells of the pancreas is organized into acinar cells, with zymogen granules
- The lumen is narrow, and form drainage tubules
- The drainage tubules produces bicarbonate
- Interlobular ducts are continued as extralobular ducts, which enters the pancreatic ducts that ends in the duodenum
-
Ductus interlobularis:
- Ions equal with plasma concentration is secreted
-
Ductus extralobularis
- HCO3- is secreted, influenced by secretion
-
Main collecting tubule
- HCO3- secretion into lumen increases, Cl- is taken up
Interspecies quantitiy of pancreatic juice secreted
- Highest
- Lowest
- Hightest: horse (6-9.5 l/day)
- Lowest:
- Chicken
- Dog (0.06-1 l/day)
Pancreas enzymes
What does the pancreatic juice contain
- Enzymes:
- α-amylase
- Lipase
- Esterase
- Nuclease
- Inactive proenzymes:
- Trypsinogen
- Chymotrypsinogen
- Proelastase
- Procarboxypeptidase
- Prophospholipase
Where are the proenzymes activated?
- In the lumen of the ileum
- The activation is initiated by enteropeptidase, which produces trypsin (active) from trypsinogen
- Trypsinogen activates other proenzymes to active form
Regulation of pancreatic juice
What are secretory activity of ducts and acini regulated by?
Hormones and neurotransmitters
Regulation of pancreatic juice
Neural regulation
-
Parasympathetic:
- N. vagus cause increased ezymatic secretion
-
Sympathetic:
- N. splanchinicus cause decreased amount of pancreatic juice
Regulation of pancreatic juice
Regulation in cephalic phase, gastric phase and intestinal phase
-
Cephalic phase
- High protein content
- Small amount of juice released
-
Gastric phase
- Parasympathetic effect dominates
- Increased enzyme secretion
-
Intestinal phase
- Influenced by chime in duodenum and jejunum
- Presence of amino acids, fatty acids or monoglycerides leads to pancreatic juice secretion that is rich in enzymes