Among the following cell types, which is responsible for the secretion of bicarbonate in pancreatic juice?
Paneth cells
Goblet cells
Kupffer's cells
Acinar cells
Acinar cells are the main secretory cells in the pancreas that produce and release pancreatic juice. This juice contains bicarbonate, which plays a crucial role in neutralizing the acidic chyme from the stomach as it enters the small intestine. The bicarbonate secretion by acinar cells helps maintain an optimal pH environment for the action of pancreatic enzymes and facilitates efficient digestion. The other options represent different cell types found in various organs but are not directly responsible for the secretion of bicarbonate in pancreatic juice. Hence, the correct answer is option 4.