Pancreas Physiology Flashcards
Describe pancreatic secretions (4 key points)
- Large volumes
- Isotonic
The main pancreatic duct joins to … to form …
Acinar cells vs Ductal cells
Acinar cells
Prominent endoplasmic reticulum
Responsible for protein synthesis and secretion
Duct cells
Numerous mitochondria
Ion transport
Main electrolyte in pancreatic juice and enzymes
Electrolyte: Bicarbonate
Enzymes: Amylases, proteases, lipases
Briefly understand the mechanism of bicarb transport in the pancreas
The goal of the ductal cells is to…
CFTR transporter (cystic fibrosis transporter) transports the bicarb to the apical side.
Sodium and water flows to … through the intercellular junctions
Pancreatic enzymes are initially released as…
zymogens (inactive enzymes)
What is the role of enterokinase?
Converts tripsinogen to trypsin, which activates all the other pancreatic enzymes.
Pancreatic secretion is controlled by (2)
Neuronal mechanisms
?
When does secretin get released?
Released by duodenal mucosa in response to acid exposure
Understand the whole mechanisms with parietal cells and H+
When is CCK released?
Released from gut endocrine cells
Triggered by fat and protein
CCK acts directly …?
Pancreatic exocrine insufficiency causes
- Chronic pancreatitis
- Cystic fibrosis
- ?
Most common etiology of pancreatic exocine insufficiency
Chronic pancreatitis (because of chronic inflammatory damage and fibrosis).
Why does cystic fibrosis cause pancreatic exocrine insufficiency?
Because of mutations in the CFTR gene
2 causes of pancreatic duct obstruction
Shwachman-Diamond syndrome
Autosomal recessive syndrome
Infancy
Bone marrow failure…
Clinical manifestations of pancreatic pathologies
Most patients will be asymptomatic!
Laboratory deficiencies caused by pancreatic pathologies
Fat soluble vitamins deficiency: A, D, E, K
When do we need imaging?
If we suspect?
First image: stone
Differential diagnosis for chronic diarrhea and steatorrhea
Small intestinal bacterial growth
?
Indirect pancreeatic function tests (3)
Fecal elastase-1
…?
What is the fecal elastase-1 test?
Most specific and sensitive indirect test.
Enzyme stays stable throughout GI, does not get digested, so you get a reliable sample. Less than 200 mcg/g is considered abnormal.
Sensitivity: to rule out
Specificity: to rule in
False positve: very watery diarrhea
