Insulin and Glucagon: Regulation of Blood Glucose Levels

Overview

• Insulin and glucagon are hormones that regulate blood glucose levels.
• Both operate via a negative feedback system.
• Their primary target organ is the liver.

Carbohydrate Consumption and Blood Glucose Levels

• Consuming carbohydrates (e.g., rice, pasta, bread) increases blood glucose levels.
  • Carbohydrates are long chains of glucose monomers.
  • During digestion, these are broken down into glucose, which is absorbed into the bloodstream.

Role of Insulin

• Insulin Secretion:
  • Triggered by increased blood glucose levels.
  • Secreted by the pancreas.
• Target Organ:
  • Liver, stimulated to convert glucose to glycogen (storage form).
  • Muscle cells also store glycogen.
• Effects on Body Cells:
  • Increases uptake of glucose by body cells.
  • Decreases blood glucose levels to optimal state.
• Associated Condition:
  • Diabetes can result from faulty insulin system.
  • Further details on diabetes will be covered in another lesson.

Foods and Drinks High in Sugar

• Same insulin response occurs with sugar-rich foods and drinks (e.g., sweets, cakes, fizzy drinks).

Role of Glucagon

• Glucagon Secretion:
  • Triggered by decreased blood glucose levels (e.g., when hungry).
  • Secreted by the pancreas.
• Target Organ:
  • Liver.
  • Stimulates breakdown of glycogen into glucose.
• Effects on Blood Glucose Levels:
  • Increases to optimal state.

Conclusion

• Regulation Mechanism:
  • Insulin and glucagon work in opposition to maintain blood glucose levels.
• Pancreatic Function:
  • Both hormones are produced by the pancreas to regulate glucose metabolism effectively.