Arizona State University (ASU) BIO202 Human Anatomy And Physiology II Exam 1 Practice Exam

Glucagon plays a crucial role in maintaining blood glucose levels, particularly during fasting or between meals. It is a hormone produced by the alpha cells of the pancreas and primarily functions to increase blood glucose levels when they are low. One of its key actions is to stimulate the breakdown of stored glycogen into glucose in the liver, a process known as glycogenolysis. Additionally, glucagon promotes gluconeogenesis, which is the synthesis of glucose from non-carbohydrate sources, such as fats and proteins. By stimulating the breakdown of fats, glucagon facilitates the release of fatty acids that can be used as an alternative energy source. When protein breakdown is stimulated, it provides amino acids that can be converted into glucose through gluconeogenesis, further aiding in elevating blood sugar levels. The other options do not accurately represent the main functions of glucagon. While it inhibits insulin secretion, this action is more of a regulatory response to ensure that glucose levels can rise when needed, rather than its primary role. Glucagon does not stimulate insulin production; in fact, insulin and glucagon have opposing effects on blood sugar levels. Lastly, rather than decreasing blood sugar levels, glucagon acts to increase them, particularly during periods of low glucose availability. Understanding