The sugar carried in the blood is glucose; the normal value of sugar in the human bloodstream is approximately 90mg per 100 bloods. Sugar is absorbed from the small intestines and is carried along the hepatic portal vein to the liver. The regulation of glucose involves the pancreas and the liver; in the pancreas are groups of special cells known as Islets of Langerhans, these cells secrete two hormones, insulin and glucagon. If the blood sugar level rises after a heavy carbohydrate meal, these cells detect this and release more insulin and less glucagon. The insulin travels to the liver and tells it to do a number of things: convert glucose to glycogen stored in the liver and muscles, also convert glucose to fat, as a result the blood sugar level falls. Adrenalin also affect the blood sugar level, at time of stress or during exercise, adrenalin will be secreted which will decrease the blood sugar level as respiration is increased.
This is a diagram that shows how the body's response to an increase in blood sugar level.