Blood Glucose Regulation

WHY IS REGULATION OF BLOOD GLUCOSE IMPORTANT?

It is important that blood glucose levels are kept relatively constant because, if the blood glucose level changes significantly, this will change the water potential of the blood.  As a result, cells will gain or lose too much water through osmosis.

RECEPTOR CELLS

Blood glucose levels are monitored by specific receptor cells, found in the islets of Langerhans in the pancreas.  There are two types of cell here:

• the alpha cells --> these secrete glucagon
• the beta cells --> these secrete insulin

HIGH BLOOD GLUCOSE LEVELS

Blood glucose levels rise when a meal containing carbohydrates is eaten and glucose is absorbed into the blood.

This rise is detected by beta cells in the islets of Langerhans, which respond by secreting insulin. This lowers blood glucose levels in several ways:

• Insulin stimulates the uptake of glucose by all respiring cells in the body, especially liver and muscle cells.  Insulin…