pancreas Flashcards
location
retroperitoneal
LV2
pancreas development
endodermal in origin
from ventral and dorsla pancreatic buds
head
flattened structure , 2-3 cm thick
includes uncinate process
attached to 2nd and 3rd portions of duodenum
gastroduodenal a defines border w/neck
endocrine function
only 1%, mostly exocrine
about 20% of blood supply to exocrine tissue
neck
2-3 cm in length
antero-superior surface supports pylorus
straddles SMV and PV
BODY
anterior surface seperated from stomach by lesser sac
posterior surface related to aorta, left adrenal, ledt renal vessels, upper 1/3 left kidney
splenic v embedded in posterior surface
inferior surface covered by transverse mesocolon
tail
short narrow
TV12
terminates at splenic hilum w/in splenophrenic lig
anteriorly related to splenic flexure of colon
may be injured during splenectomy (fistula)
main duct
duct of wirsung length of pancreas merges w/common bile duct at ampulla of vater 2-4mm diameter 20 secondary brr higher ductal pressure prevents backflow
accesory duct
duct of santorini
drains superior portion of head and empties separately into duodenum
exocrine microanatomy
secretory acini and ducts- 98% of pancreatic mass
acini- 20-40 secretory cells coalesce into sac-like unit, secrete digestive enzymes
endocrine microanatomy
islets of langerhans alpha cells beta cells delta cells PP cells minor: delta-1, EC, epsilon
alpha cells
25-35% of iselt cells
produce glucagon
beta cells
55-65% of islet cells
produce insulin, amylin
delta cells
5-15% of islet cells
produce somatostatin
PP cells
<2% of islet cells
produce pancreatic polypeptide
delta-1
1% of islet cells
produce VIP
also found in exocrine acini and ductal epithelium
EC cells
1% of islet cells
produce: secretin, motilin, substance P
also found in exocrine acini, ductal epithelium
epsilon cells
1% of islet cells
produce ghrelin
stimulatory inputs
glucose, amino acids, glucagon, GIP,CCK, sulfonylurea compounds, B-sympathetics
inhibitory inputs
somatostatin, amylin, pancreastatin, alpha-sympathetics
pancreatic polypeptide
stimulates gastric chief cells
inhibits bile secretion and intestinal motility
inhibits pancreatic enzymes and bicarb secretion
VIP
similar action of glucagon (hyperglycemic and glycogenolytic)
also affects secretory activity and gut motility
stimulates pancreatic exocrine secretion
secretin
acts locally
stimulates bicarb secretion and other pancreatic enzymes
ghrelin
stimulates appetite
