pancreas lecture Flashcards
pancreatic development
foregut and midgut join in developing embryo; ventral (part of hepatobiliary bud become liver and gall bladder) and dorsal buds form; duodenum rotates to form a C-shape - ventral bud swings round to lie adjacent to dorsal bud; both fuse and ventral bud duct becomes main pancreatic duct
where is islet tissue most abundant
tail
where does pancreas lie
mainly on posterior abdominal wall to hilum of spleen
close relations with and supply from
coeliac and superior mesenteric arteries
angiography
blush forms (tumour) as stimulates own angiogenesis
somatostatin
endocrine cyanide - suppress release of most other hormones and other biological functions
cystic fibrosis
effects both exocrine and endocrine effects
islets
lose connection from branching duct system and become islets; tail > head
duct cell, centroacinar and acinar cells form what functional unit
blind endotubules
bicarbonate secretions
prevents damage to duodenal mucosa, raises pH to optimum range for enzymes in pancreas, washes low volume enzyme secretion out of pancreas into duodenum
as empty more stomach contents into duodenum (low pH)
raise in bicarbonate secretion up to pH 5 (other mechanisms also help neutralise acid to raise pH further - Brunner’s glands, bicarbonate in bile)
exchange driven by electrochemical gradients
high EC (blood) Na+ vs IC (duct cell); high Cl- in lumen vs IC (duct cell)
K+ to blood via K+ channel and Cl- to lumen via Cl-channel
facilitated diffusion
what do lipases require presence of for effective action
bile salts
pancreatic secretions
adapt to diet (high protein, low carbs increases prportion of proteases and decreases proportion of amylases)
