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Pancreas Secretion

rates

i shown

Secretin

GASTROINTESTINAL PHYSIOLOGY

General circulation

‘Cholecystokinin

■ Sympathetic fibers ■Vagus fibers Iparasympathetic) -Celiac ganglion

Pancreas

induced

lenzymes)

Entero-

kinase

Trypsinogen

'Pancreatic acinus ■ Pancreatic duet - Portal vein

Starcb

MaUotf»^ise-

-Secrelin

■ Cholecysto-kinin

.___Lacteal

Protein

•Secretin

Smali bowe

“Cholecysto

kinin

Figurę 7.27 Pancreas Secretion

Secretion by the pancreas in under neural and hormonal c.ontrol. The parasympathetic system (vagus nerve) stimulates secretion. Secretin is secreted by the neuroendocrine S cells in response to the presence ot acid in the duodenum. It acts on the ductal cells of the pancreas to stimulate the secretion of fluid with a high HCO, con-tent. Cholecystokinin is secreted by I cells in response to fats in the duodenum and upper jejunum. It acts on the arinar cells to stimulate the secretion of enzymes. .Vor shown in the figurę: Trypsin in the lumen ol the duodenum activate$ other protease precursors (chy-motrypsinogen and proc.arboxypcptidasc) to theii ac.tive forms (chy-motrypsin and cadjoxypeptidase). Notę: Secretin and CCK are secreted throughout the duodenum, espedally proximally.

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