Regulation of blood sugar or glucose level is a negative feedback mechanism which aims at maintaining normal blood glucose level. Two hormones, insulin and glucagon are involved in regulation of blood glucose level. Insulin stimulates liver cells to convert glucose to glycogen whereas glucagon stimulates liver cells to break down glycogen to glucose.
Increase in blood glucose level
After a meal, blood glucose level increases, pancreas secretes more insulin, liver cells convert glucose to glycogen for storage and body cells increase glucose uptake for respiration. These activities decrease blood glucose level to normal.
Decrease in blood glucose level
During fasting or exercise, blood glucose level decreases, pancreas secretes more glucagon, liver cells break down glycogen to glucose and body cells decrease glucose uptake for respiration. These activities increase blood glucose level to normal.