Final answer:
The excretion path of pancreatic enzymes starts with their secretion by the pancreas as inactive precursors, followed by activation in the small intestine. Active enzymes facilitate digestion, and any remnants are ultimately excreted through the gastrointestinal tract, with by-products sometimes measured in urine testing.
Step-by-step explanation:
The path of excretion of pancreatic enzymes involves their production by pancreatic acinar cells as inactive precursors. These enzymes are secreted into the small intestine, where they are activated by the enzyme enteropeptidase produced by intestinal brush border cells. The process of enzyme activation is crucial as active enzymes in the pancreas could lead to digestion of the pancreas itself, causing pancreatitis.
Once activated, these enzymes participate in chemical digestion within the small intestine. Pancreatic amylase breaks down starches, pancreatic lipase digests lipids, and pancreatic nucleases manage nucleic acid digestion. Post-digestion, the by-products and unused portions of these enzymes are absorbed or continue through the gastrointestinal tract until they are eventually excreted.
For example, a direct test of pancreatic function may involve measuring the excretion of products of enzyme activity, such as PABA, which is produced from a specific synthetic peptide and then measured in the urine.