Final answer:
If glucagon is not functioning properly, blood glucose levels would predictably decrease during the postabsorptive state, as glucagon's role is to raise blood glucose levels by promoting glycogenolysis and gluconeogenesis.
Step-by-step explanation:
If glucagon is not functioning properly in a patient, it is predicted that: c. blood glucose will decrease.
Glucagon plays a critical role in the regulation of blood glucose levels, especially during the postabsorptive state, also known as the fasting state. In the absence of meals, blood glucose levels begin to drop as the body starts utilizing stored glycogen for energy. As glucose levels fall, normally, glucagon is released from the alpha cells of the pancreas. It stimulates the liver to break down glycogen into glucose (a process known as glycogenolysis) and release it into the blood, thereby increasing blood glucose levels. In addition to glycogenolysis, glucagon also promotes gluconeogenesis, the synthesis of glucose from non-carbohydrate sources, further contributing to the maintenance of blood glucose levels. Should glucagon not function properly, these processes would be impaired, and the individual's blood glucose levels would be expected to decrease. The actions of glucagon are counterbalanced by insulin, which promotes glucose uptake and storage, effectively lowering blood glucose when high. Together, these two hormones maintain homeostatic glucose levels in the body.