Pancreas Flashcards
what are the 4 parts of the pancreas
- head and uncinate process
- neck
- body
- tail
what are the ducts of the pancreas
○ Main pancreatic duct joins the common bile duct at the hepatopancreatic ampulla (Ampulla of Vater)
○ Accessory pancreatic duct drains to the minor duodenal papilla (less important)
what are the arterial supplies to the pancreas
Head:
- Pancreaticoduodenal branches of the gastroduodenal artery
- Superior mesenteric artery
Neck, Body, Tail
- Branches of splenic artery (celiac trunk) supply neck, body and tail
what is the venous supply of the pancreas
Splenic vein & superior mesenteric vein
the exocrine function s of the pancreas are carried out by the ?
acini
Most of the cells making up the acinus =
acinar cells
40-50 acinar cells form a
spherical acinus
what are the general function of acinar cells:
○ Secretion of inactive pancreatic enzymes (zymogens)
○ Rich RER, lots of granules (filled with zymogens)
○ CCK major stimulator
what are the general function of centroacinar cells:
○ Secretion of HCO3-rich fluid
○ Secretin major stimulator
Centroacinar cells and intercalated duct cells can both secrete ? in response to ?
bicarbonate
secretin
what are the phases of pancreatic secretion
- cephalic
- gastric
- intestinal
what are the regulation of pancreatic secretion
both neural and hormonal control
what does secretin do to the pancreas
stimulates fluid secretion (HCO3-)
what does CCK do to the pancreas
stimulates enzyme secretion
what does endopeptidases do?
through hydrolysis, cleave peptide bonds at certain amino acids
endopeptidases include
pepsin
trypsin
chymotrypsin
elastase
what does exopeptidases do?
through hydrolysis, cleave peptide bonds at the carboxyterminus
what do trypsin inhibitor do
prevents activation of trypsin inside secretory cell and in ducts of pancreas
What is the role of trypsinogen activation in acute pancreatitis?
- It’s a digestive enzyme (trypsin) capable of activating other zymogens
○ Reasonable to hypothesize that this leads to a straightforward autodigestion of the pancreas
what is acute pancreatitis?
duct blockage and acinar cell injury result in profound pancreatic damage
what are the pathophysiology for acute pancreatitis
- alcohol ingestion
- biliary tract obstruction
alcohol ingestion leads to…
excessive protein in pancreatic secretions, “plugs” the ducts
biliary tract obstruction means that
Pancreatic secretions are stuck in the ducts, due to a gallstone or sludge blocking outflow
what is the common factor of acute pancreatitis
blockage of ducts
what can be seen in any stage of acute pancreatitis
fat necrosis
Free pancreatic lipases cleave triglycerides in the abdominal cavity -> fatty acids that combine with extracellular calcium. This is known as
Saponification
what is chronic pancreatitis
Inflammation of the pancreas with irreversible destruction of exocrine parenchyma, fibrosis, and, in the late stages, the destruction of endocrine parenchyma
what is thought to be related to multiple episodes of acute pancreatitis
chronic pancreatitis
what are pseudocysts
Localized collections of necrotic-hemorrhagic material rich in pancreatic enzymes
how are this pseudocysts formed
Formed by the walling off of fat necrosis with fibrous tissue
