Damages nerves → neuropathy (tingling, pain, numbness in hands and feet).
Increased risk of heart attack and stroke.
The PANCREAS is the organ that monitors and regulates blood glucose — it contains specialised cells that detect glucose concentration and release hormones accordingly.
Insulin — Lowering Blood Glucose
After eating a meal:
Carbohydrates are digested → glucose absorbed into blood → blood glucose RISES.
Pancreas BETA CELLS detect the rise and release INSULIN into the bloodstream.
Insulin travels to the LIVER and MUSCLE CELLS and causes them to:
Absorb MORE glucose from the blood.
Convert glucose → GLYCOGEN (a storage polymer) — this is called GLYCOGENESIS.
Blood glucose concentration FALLS back to the set point.
This is NEGATIVE FEEDBACK — the response (insulin release + glucose storage) opposes the original change (rising glucose).
Glucagon — Raising Blood Glucose
Between meals, during fasting or after exercise:
Cells use glucose for respiration → blood glucose FALLS.
Pancreas ALPHA CELLS detect the fall and release GLUCAGON into the bloodstream.
Glucagon travels to the LIVER and causes it to:
Break down stored GLYCOGEN back into glucose — this is called GLYCOGENOLYSIS.
Release glucose back into the blood.
Blood glucose concentration RISES back to the set point.
Again this is NEGATIVE FEEDBACK — glucagon release opposes the fall in glucose.
Type 1 and Type 2 Diabetes
Both types of diabetes result in poorly controlled blood glucose — but for different reasons.
TYPE 1 DIABETES:
Cause: The immune system attacks and destroys the BETA CELLS in the pancreas (autoimmune condition).
Result: Little or no insulin produced — blood glucose cannot be lowered after eating.
Onset: Usually in childhood or adolescence.
Treatment: INSULIN INJECTIONS (or insulin pump) — insulin cannot be taken as a tablet because it is a protein and would be digested.
Patients must monitor blood glucose and adjust insulin doses accordingly.
TYPE 2 DIABETES:
Cause: Body cells become RESISTANT to insulin — they no longer respond to it properly. The pancreas may still produce insulin, but it doesn't work.
Result: Blood glucose remains elevated after eating.
Risk factors: Obesity, lack of exercise, poor diet (high sugar/refined carbs), family history, age.
Medication: Metformin (increases cell sensitivity to insulin).
In advanced cases: insulin injections may also be needed.
⚠️ Common Mistake
INSULIN lowers blood glucose by promoting GLYCOGEN STORAGE (glucose → glycogen). GLUCAGON raises blood glucose by promoting GLYCOGEN BREAKDOWN (glycogen → glucose). Students constantly confuse which hormone does which. Memory trick: INsulin = INto storage. Glucagon = Get glucose out of storage.
📌 Key Note
Glucose too high → pancreas releases INSULIN → glycogen stored → glucose falls. Glucose too low → pancreas releases GLUCAGON → glycogen broken down → glucose rises. Type 1: no insulin (autoimmune). Type 2: insulin resistance (lifestyle).
🎯 Matching Activity — Insulin or Glucagon?
Match each statement to the correct hormone — insulin or glucagon. — drag the symbols on the right to match the component names on the left.
Insulin
Drop here
Glucagon
Drop here
Insulin
Drop here
Glucagon
Drop here
Insulin
Drop here
Released when blood glucose is TOO LOW — between meals or after exercise
Causes liver and muscle cells to convert glucose → glycogen for storage
Missing or ineffective in diabetes — leads to hyperglycaemia if untreated
Released when blood glucose is TOO HIGH — after eating a meal
Causes liver cells to break down glycogen → glucose and release it into blood
⚽ FIFA Worked Examples
Blood Glucose Negative Feedback
Describe what happens to blood glucose and hormones after a person eats a meal containing a large amount of carbohydrates.
Pancreas beta cells detect the rise → release INSULIN into the blood
F
Insulin travels to liver and muscles → glucose converted to glycogen (glycogenesis)
A
Blood glucose FALLS back to ~5 mmol/L — negative feedback complete
⭐ Higher Tier Only
Insulin (from pancreatic beta cells) causes glucose uptake and glycogenesis (glucose → glycogen). Glucagon (from alpha cells) causes glycogenolysis (glycogen → glucose) and gluconeogenesis (making new glucose). Negative feedback maintains blood glucose at ~4–6 mmol/L. Type 1: autoimmune destruction of beta cells — insulin injections essential (cannot take orally as insulin is a protein, digested in gut). Type 2: insulin resistance — managed with diet, exercise, metformin. Both lead to hyperglycaemia if untreated.
🎯 Test Yourself
Question 1 of 3
1. Blood glucose rises after eating. Which hormone is released and what does it do?
2. Why must Type 1 diabetics inject insulin rather than take it as a tablet?
3. What is the key difference between Type 1 and Type 2 diabetes?
⭐ How Well Do You Understand This Topic?
Be honest with yourself — this helps you know what to revise!
Don't get itGetting thereNailed it!
🤖 Ask Mr Badmus AI
Stuck? Just ask! 💬
I'll use FIFA for calculations and flag Higher/Triple content clearly.