Unit 4 -Pancreas Flashcards
What leads to secretion from the exocrine pancreas?
hormones released by stomach and duodenum in response to gastric distension and/or ingesta
What does the pancreas secrete?
bicarbonate-rich fluid and pro-enzymes
What is the role of the bicarbonate-rich fluid that is released from the pancreas?
it is to neutralize acid from the stomach
What specific pro-enzymes are released from the pancreas?
trypsinogen, chymotrypsinogen, pro-phospholipase, pro-lipase etc.
How does the exocrine pancreas prevent autodigestion?
it stores its enzymes and secretes them in an inactive form
When are pancreatic enzymes activated?
in the intestinal lumen
What is the exocrine pancreas made up of?
acini/acinar cells, ducts, interstitium, vessels, and nerves
What do the acinar cells contain?
zymogen granules, which are vesciles filled with pro-enzymes for digestion
What defense mechanisms does the exocrine pancreas have to prevent autodigestion?
proenzymes are not activated until in the intestinal lumen, enzyme inhibitors
What enzyme inhibitors does the exocrine pancreas have?
Pancreatic secretory trypsin inhibitor, alpha antitrypsin, alpha 2 macroglobulin
Generally, what are some lesions/syndromes that can happen to the pancreas?
exocrine pancreatic insufficiency, inflammation, hyperplasia, and neoplasia
When does exocrine pancreatic insufficiency occur?
when the pancreas does not produce adequate amounts of digestive enzymes
What does exocrine pancreatic insufficiency lead to?
maldigestion
You typically need to lose ______ of the exocrine pancreas before clinical signs of EPI to develop.
greater than or equal to 90 percen
What clinical signs are associated with exocrine pancreatic insufficiency?
polyphagia, weight loss with muscle wasting, yellowish, poorly digested, loose and pulpy feces, increased fecal volume, and frequent defecation
How do you diagnose EPI antemortem?
serum TLI (Trypsin-like immunoreactivity)
What does a TLI test measure?
trypsinogen and trypsin-like immunoreactivity in the blood
What are some causes of EPI?
juvenile pancreatic atrophy and chronic pancreatitis
What species is juvenile pancreatic atrophy the most common cause of EPI in?
dogs
What age animal typically gets juvenile pancratic atrophy?
typically 6-36 months
What species is juvenile pancreatic atrophy reported in?
dogs and calves
What causes juvenile pancreatic atrophy?
either auto-immune destruction of the pancreas or it is congenital
What species is chronic pancreatitis the most common cause of EPI in?
cats
What age animal typically gets chronic pancreatitis?
typically middle age to older
What is chronic pancreatitis the result of?
progressive destruction of the pancreas by necrosis, inflammation, and fibrosis
What can be impaired by chronic pancreatitis?
both exocrine and endocrine function
What breeds is canine juvenile pancreatic atrophy an inherited condition in?
german shepards and rough-coated collies
What provides as evidence for autoimmune disease in canine juvenile pancreatic atrophy?
marked T-lymphocyte infiltration during the progression of acinar atrophy and breed predisposition
What is pancreatitis?
inflammation of the pancreas
What does pancreatitis result from?
premature activation of digestive enzymes within the pancreatic acinar cells causing pancreatic auto-digestion
What forms of pancreatitis are there?
chronic and acute
What species is acute pancreatitis clinically important in?
dogs
What clinical signs are associated with acute pancreatitis in dogs?
anorexia, vomiting, diarrhea, painful abdomen, and fever
What can severe cases of acute pancreatitis lead to?
shock, DIC, and death due to multi-organ dysfunction
What clinical signs are associated with acute pancreatitis in horses?
colic, +/- shock, clinical signs are non-specific and resemble signs of small obstruction or inflammation
What signalment is associated with acute pancreatitis?
it is more common in middle-aged, obese, sedentary, small-breed bitches\
What may an animal with acute pancreatitis have a history of?
high fat meal and dietary indiscrestion
What diagnostics are used to diagnose acute pancreatitis?
CBC (leukocytosis), serum chemistries, and imaging
What is the pathogenesis of acute pancreatitis?
- Zymogen granules fuse with lysosomes 2. Cathepsin B activates trypsinogen to trypsin 3. Pancreatic secretory trypsin inhibitor overwhelmed 4. Trypsin activates additional enzymes in the pancreas 5. Autodigestion 6. Inflammation
What are some initiating events that lead to acute pancreatitis?
dietary, trauma, ischemia, drugs, toxins, infectious, metabolic, and idiopathic
What gross lesions are associated with acute necrotizing pancreatitis?
hyperemia, hemorrhage and necrosis, fibrinopurulent exudate, peripancreatic fat necrosis, and fibrinous adhesions to adjacent structures and omentum
What happens to animals with chronic (relapsing) pancreatitis?
they suffer recurrent, intermittent attachs that contribute to the morphological and functional destruction of the gland
How does chronic (relapsing) pancreatitis lead to exocrine pancreatic insufficiency and diabetes mellitus?
- Necrotic/inflamed focus is liquefied, sequestered, or replaced by fibrous connective tissue 2. Loss of pancreatic parenchyma + fibrosis 3. Decreased pancreatic mass leading to exocrine pancreatic insufficiency and diabetes mellitus
What are some sequela to pancreatitis?
bile duct obstruction, anorexia and vomiting, hepatic necrosis, peripancreatic fat necrosis, diabetes mellitus, liquefactive necrosis of the pancreas, peripancreatic inflammation, and systemic release of inflammatory mediators and activated digestive enzymes
In regards to diabetes mellitus, what can severe acute pancreatitis lead to?
+/- temporary diabetes
In regards to diabetes mellitus, what can severe extensive, chronic pancreatitis lead to?
+/- permanent diabetes
How does chronic fibrosing pancreatitis with peripancreatic adhesions lead to jaundice?
- Chronic fibrosing pancreatitis with peripancreatic adhesions 2. bile duct obstruction 3. dilated bile duct and gall bladder 4. jaundice
What clinical signs are associated with equine pancreatitis?
colic +/- shock
What is the pathogenesis of equine pancreatitis?
- severe strongyle infection 2. migration of Strongylus equinus larvae through the pancreas 3. Eosinophilic granulomas and/or fibrosis 4. pancreatitis
What species has pancreatic exocrine nodular hyperplasia been reported in?
dogs, cats, and cattle
True or False: Pancreatic exocrine nodular hyperplasia is considered an incidental finding
TRUE
What causes pancreatic exocrine nodular hyperplasia?
age-related hyperplastic foci and response to previous injury
What species is age-related hyperplastic foci common in?
dogs and cats
Age-related hyperplastic foci have a positive correlation with age ______ of the presence or absence of pancreatic inflammation, necrosis, or fibrosis.
regardless
What is the appearance of pancreatic exocrine nodular hyperplasia?
multiple, small, white to tan, well-circumscribed nodules 1-3mm in diameter
True or False: Neoplasias of the exocrine pancreas are common
FALSE
What types of neoplasias are often found in the exocrine pancreas?
adenoma and adenocarcinomas
What do neoplasias of the exocrine pancreas arise from?
acinar or ductal epithelium
Are adenomas in the pancreas common?
no they are rare and often clinically silent
What is the appearance of pancreatic adenomas?
single/solitary, well-demarcated and encapsulated, typically have multiple nodules with hyperplasia
Are pancreatic adenocarcinomas typically benign or malignant?
malignant
What animals do pancreatic adenocarcinomas generally occur in?
older dogs
What clinical signs are associated with pancreatic neoplasms?
abdominal pain, vomiting, weight loss, abdominal mass, +/- jaundice, +/- ascites
What is the biological behavior of pancreatic neoplasias?
they are aggressive tumors - disease is often advanced by the time of diagnosis
Where do pancreatic neoplasms typically metastasize to?
lung, liver, spleen, and kidney
