The Regulation of Blood Glucose Levels and Homeostasis

Introduction

• Sugary snacks are broken down into simple sugars like glucose.
• Blood glucose levels increase after consuming sugar.
• Homeostasis: the body's tendency to maintain constant internal conditions.

Role of the Pancreas in Blood Glucose Regulation

• Hormones Involved:
  • Insulin
  • Glucagon

Insulin Release

1. High Blood Glucose Levels:
   • Glucose enters beta cells in the pancreas.
   • Beta cells release insulin into the bloodstream.
2. Effects of Insulin:
   • Binds to receptors on liver cells.
   • Liver cells take in more glucose.
   • Glucose is converted to glycogen (storage molecule).
3. Outcome:
   • Blood glucose levels decrease.
   • Less insulin is released, stabilizing blood glucose at the set point.

Glucagon Release

1. Low Blood Glucose Levels:
   • Alpha cells in the pancreas release glucagon into the bloodstream.
2. Effects of Glucagon:
   • Binds to receptors on liver cells.
   • Signals liver cells to break down glycogen to glucose.
3. Outcome:
   • Glucose is released into the bloodstream, increasing blood glucose levels.
   • Less glucagon is released, stabilizing blood glucose at the set point.

Negative Feedback Mechanism

• Insulin and glucagon have opposing effects.
• They work together to maintain homeostasis of blood glucose levels.

Diabetes and Homeostasis Disruption

• Type 1 Diabetes:
  • Immune system destroys beta cells, leading to no insulin production.
• Type 2 Diabetes:
  • Pancreas produces insulin, but target cells do not take up glucose.
• Result: Elevated blood glucose levels due to lack of glucose uptake by cells.

Conclusion

• Importance of homeostasis in regulating blood glucose levels for overall health.