Final answer:
Insulin is the hormone that reduces blood glucose levels in response to hyperglycemia by increasing cellular uptake of glucose and stimulating glycolysis and glycogen synthesis. It is secreted by the beta cells of the pancreas.
Step-by-step explanation:
The hormone involved in reducing the amount of glucose in the blood in reaction to hyperglycemia is insulin. When the blood glucose level rises, such as after a meal, the pancreas releases insulin. Insulin helps in lowering blood glucose by enhancing the rate of glucose uptake and utilization by cells and stimulating the liver to convert glucose to glycogen for storage. It is a key player in the regulation of blood glucose levels and operates on a negative feedback loop, where elevated insulin levels from beta cells decrease in response to falling blood glucose levels.