Homeostasis & Insulin: Keeping Your Sugar Levels Steady

 

What is Homeostasis?

• Homeostasis is the maintaining a contant state or internal environment.

Key Concept:
Think of homeostasis as your body’s thermostat, keeping everything balanced—like temperature, water levels, and blood sugar.

 

Blood Glucose Regulation: The Role of Insulin

• When you eat, your blood sugar levels rise.
• To keep them balanced, your body uses two hormones: insulin and glucagon.
• These hormones are created in the pancreas
• The pancreas produes glucagon when the blood glucose levels drop. This causes the liver and muscle cells to convert the stored glycogen into glucose for energy
• The pancreas produes insulin when the blood glucose levels rise. This causes the liver and muscle cells to convert glucose into glycogen for storage

 

Hormone	Produced by	Function
Insulin	Pancreas (beta cells)	Lowers blood glucose by helping cells absorb glucose and storing it as glycogen in the liver.
Glucagon	Pancreas (alpha cells)	Raises blood glucose by converting glycogen in the liver back into glucose.

 

 

 

 

Negative Feedback in Blood Sugar Control

Negative feedback ensures your blood sugar stays around a set point.
If it gets too high or low, your body acts to bring it back to normal.

High Blood Glucose (After Eating):

1. Pancreas detects high glucose levels.
2. Insulin is released.
3. Insulin signals liver and muscles to store glucose as glycogen.
4. Blood glucose returns to normal.

Low Blood Glucose (Between Meals):

1. Pancreas detects low glucose levels.
2. Glucagon is released.
3. Glucagon signals liver to break down glycogen into glucose.
4. Blood glucose returns to normal.

 

Diabetes: When Homeostasis Fails

Type 1 Diabetes

• This is when teh body is not able to produce enough insulin in the pancreas.
• This causes the blood glucose levels to be high as glucose cannot be converted into glycogen.
• People who have type 1 diabetes use insulin injections which rises insulin in the blood stream allowing the excess glucose to be converted to glycogen.
• It is important for people with type 1 diabetes to monitor their diet and exercise to try and control their blood glucose levels.

Key symptoms include:

• Tiredness and feeling weak
• weight loss
• blurry vision
• thirst
• at times loss of consciousness

 

Step-by-Step Example: Insulin in Action

Scenario:
You eat a chocolate bar, and your blood glucose rises from 90 mg/dL to 150 mg/dL. Insulin helps reduce it to normal in 30 minutes.

How It Works:

1. High Blood Glucose: The rise is detected by the pancreas.
2. Insulin Released: Insulin helps body cells absorb glucose and signals the liver to store it as glycogen.
3. Blood Glucose Drops: Levels return to the normal range (about 90 mg/dL).