Which statement about insulin and glucagon is NOT true?

Insulin is produced by beta cells of the pancreas, not alpha cells. Alpha cells are responsible for the production of glucagon, which plays a crucial role in raising blood glucose levels. In contrast, insulin's primary function is to lower blood glucose levels by facilitating the uptake of glucose into various tissues, promoting its storage as glycogen, and stimulating other anabolic processes.

The statement regarding insulin promoting glucose in tissue accurately reflects its role in enhancing the uptake and utilization of glucose, while insulin's secretion is indeed stimulated by parasympathetic nervous activity, particularly following food intake. On the other hand, glucagon does not promote glycogenesis; instead, it stimulates glycogenolysis and gluconeogenesis, processes that increase blood glucose levels. Therefore, the only statement that is not true is the one that claims insulin is produced by alpha pancreatic cells.