By Stephen Razos

Glucose feedback

1. Insulin is secreted by the Islets of Langerhan which are special groups of cells in the pancreas.

2. After a carbohydrate meal, the level of glucose in the blood will start to rise as the digestive system breaks up and absorbs carbohydrates as glucose.

3. After several hours without a meal, the blood sugar level will fall as cells use up the glucose in aerobic respiration. 

4. As the blood sugar concentration rises, the Islets of Langerhan are stimulated to secrete insulin.

5. Although most cells in the body respond to insulin the main target organ for insulin is the liver. It is there that glucose is converted into glycogen. Excessive intake of carbohydrates saturates glycogen stores in the body and causes excess glucose to be stored as fat.

6. When blood sugar levels fall, not only does the pancreas make less insulin, but it is stimulated to produce another hormone called glucagon. Glucagon acts on the liver to cause the breakdown of glycogen into glucose before releasing it into the blood. Glucagon has the opposite effect of insulin.

7. Negative feedback causes the release of insulin and glucagon to slow down when blood sugar levels drop to normal levels.