Glucagon is secreted by which cells in the pancreas, and what is its effect?

Glucagon is a hormone secreted by the alpha cells of the pancreas. Its primary function is to increase plasma glucose levels, especially in response to low blood sugar levels. When blood glucose levels drop, glucagon is released into the bloodstream. It stimulates the liver to convert stored glycogen into glucose through a process called glycogenolysis and also promotes gluconeogenesis, which is the production of glucose from non-carbohydrate sources. This increase in glucose availability serves to raise blood glucose levels back to a normal range.

Understanding the specific roles of the different types of pancreatic cells is crucial. Alpha cells are responsible for producing glucagon, while beta cells produce insulin, which has the opposite effect—lowering blood glucose levels. Delta cells, on the other hand, secrete somatostatin, a hormone that inhibits both glucagon and insulin secretion. Therefore, recognizing the function of glucagon and the cells that produce it is essential for grasping how the body manages blood sugar levels effectively.