Control of blood glucose concentration by pancreas and insulin

Regulating blood glucose

Glucose is needed by cells for respiration. It is important that the concentration of glucose in the blood is maintained at a constant level and controlled carefully. Insulin is a hormone produced by the pancreas which regulates glucose concentrations in the blood.

If the blood glucose concentration is too high, the pancreas produces the hormone insulin, this causes glucose to move from the blood into the cells. In liver and muscle cells excess glucose is converted to glycogen for storage, and will be used at a later date.

Action of insulin

Low glucoseHigh glucose
Effect on pancreasInsulin not secreted into the bloodInsulin secreted into the blood
Effect on liverDoes not convert glucose into glycogenConverts glucose into glycogen
Effect on blood glucose levelIncreasesDecreases

The diagram illustrates how insulin works in the body:

Too much glucose. Pancreas produces insulin, body cells  absorb glucose, blood glucose reduced. Normal levels, insulin not produced by pancreas, less glucose absorbed, blood glucose remains same.