Trypsinogen is an inactive enzyme of pancreatic juice. An enzyme,enterokinase,activates it. Which tissue/cell secretes this enzyme? How is it activated?

(N/A) Trypsinogen is an inactive precursor (zymogen) secreted by the pancreas.
It is converted into its active form,Trypsin,by the enzyme Enterokinase.
Enterokinase is secreted by the intestinal mucosa (specifically the brush border cells of the small intestine).
This activation is a crucial step in protein digestion,as active Trypsin then activates other pancreatic enzymes like chymotrypsinogen and procarboxypeptidase.