Learning focus
Use precise biological vocabulary, trace control pathways, explain cause-and-effect mechanisms, interpret diagrams and apply ideas to unfamiliar contexts.
Cause and signs
In Type 1 diabetes, insulin-producing cells of the pancreas are destroyed, so little or no insulin is produced. Blood glucose concentration becomes abnormally high, and glucose may appear in urine because the kidneys cannot reabsorb all the filtered glucose.
Consequences
Without effective treatment, cells may be unable to use blood glucose normally and the body may break down fat and protein. Water loss and dehydration can occur because glucose in urine lowers water potential. The syllabus requires the main signs of high blood glucose and glucose in urine.
Insulin treatment
Insulin is administered to lower blood glucose. Dose and timing must be coordinated with food intake and activity. Insulin is a protein and would be digested if swallowed, so it is normally delivered by injection or pump. Treatment controls the condition but does not restore pancreatic cells.
Monitoring and balance
Too little insulin allows glucose to remain high; too much can cause dangerously low blood glucose. Monitoring enables a suitable dose. Diet and exercise also influence glucose concentration but do not replace insulin in Type 1 diabetes.
Practical or data skill
Interpret glucose measurements from a diabetic patient and identify when insulin may have been administered. Keep the activity educational and avoid making personal medical recommendations.
Examination tip
The required treatment is administration of insulin. Do not state that antibiotics or glucagon treat Type 1 diabetes.
Review questions and suggested answers
Question 1
State two signs of Type 1 diabetes.
Suggested answer
Increased blood glucose concentration and glucose in urine.
Question 2
Why is insulin usually not taken as a tablet?
Suggested answer
It is a protein and would be digested in the alimentary canal.
Question 3
What is the purpose of insulin treatment?
Suggested answer
To lower and control blood glucose concentration.
