How Does Our Body Respond to the Rise in Blood Glucose?

The concentration of glucose in the blood is very tightly regulated. When the level of circulating glucose climbs above the normal fasting level, the pancreas releases the hormone insulin (see Figures 4.2 and 4.3). Insulin will interact with receptors on muscle cells and fat cells and promote the movement of glucose into these cells. Because skeletal muscle and fat cells together tend to make up more than half of our total body mass, the net effect is a fairly rapid lowering of the glucose concentration. Insulin increases the movement of glucose in these cells by increasing the number of glucose transport proteins on their plasma membranes. As the level of glucose returns to the normal fasting level, the pancreas responds by releasing less insulin into circulation.
 

All cells in our body will continuously take glucose from our blood throughout the day to help meet their need for energy. However, after a meal, the liver, muscle, and fat cells will take a lot more glucose out of the blood than they immediately need. This allows blood glucose levels to quickly return to a normal fasting concentration.
 

Increased blood glucose levels causes the release of insulin to process, use, and store carbohydrate.