Living with diabetes
Living with diabetes

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Living with diabetes

3.8 Glucagon

Glucagon is another hormone produced by the pancreas.


Question: Can you recall which cells make glucagon?


It is produced by the α (alpha) cells of the islets of Langerhans in the pancreas (see Figure 2).

Glucagon causes an increase in the blood glucose level. The glucagon level in the blood tends to decrease as the glucose level increases and increases when the level of glucose decreases. It works in the opposite direction to insulin. It stimulates the liver to break down glycogen (the molecule synthesised from glucose that acts as a glucose store) and release glucose into the blood.

You may wonder why the body needs a hormone to increase glucose levels. Besides having to avoid circumstances where blood glucose is too high, the body also needs to be protected from glucose levels that are too low, as the brain does not function properly in these circumstances, as you saw earlier. There are lots of hormones that increase glucose levels by stimulating glycolysis, and glucagon is one of the most important.

You have been reading about some very complex processes in the body. Try Activity 3 to see if your knowledge of the processes involved in diabetes has increased.

Activity 3: The effect of drinking a sugary drink – revisited

Timing: 0 hours 10 minutes

Make brief notes on the effect that a drink containing a lot of glucose or digestible sugar might have on blood glucose level, in:

  • (a) someone with diabetes; and

  • (b) someone without diabetes.


How has your answer differed from that to Activity 2? In someone without diabetes, the blood glucose level goes up quickly and then starts to decrease, staying within normal limits. A person with some insulin but not enough, who drinks a sugary drink, will find their blood glucose level goes above the normal limits. (Blood glucose levels can reach 20 mmol/l or more after a sugary drink.) The blood glucose level comes down much more slowly in people with diabetes than in people who have a normal amount of insulin. The level to which it falls after a sugary drink depends on how much insulin is present. If there is no insulin available at all, the blood glucose level remains very high.


Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371