Blood sugar regulation

Leon just finished his lunch, a delicious pasta dish, and a slice of chocolate cake for dessert. Now all he wants to do is lie on the sofa and watch the football. But while he rests, inside his body, the hard work is just about to begin. Leon’s body starts digesting, or breaking down the food he had for lunch. The pasta and the cake Leon ate were rich in carbohydrates.

They are now broken down into simple sugars that enter his bloodstream. One of these sugars is glucose. Before lunch, the level of glucose in Leon’s bloodstream was somewhere between seventy and one hundred milligrams per deciliter of blood. Now, it rises to around one hundred and forty milligrams per deciliter of blood. That’s much higher than normal!

And this triggers a response from a specific organ, the pancreas. Warning! Warning! The levels of glucose in Leon’s blood are too high. Insulin, prepare to leave the pancreas.

And, go! Insulin is a hormone - a chemical messenger that gives information to different parts of the body. When insulin leaves the pancreas, it enters the bloodstream and travels around the body. Insulin delivers instructions to different cells and organs about what they should do with excess glucose. Cells receive an instruction to take in glucose.

In cells, glucose is used in a process called cellular respiration. When cells absorb glucose, this removes some of it from the bloodstream, but not enough to return levels back to normal. So insulin also travels to the organ next to the pancreas: the liver. After receiving instructions from insulin, the liver does two things to reduce the amount of glucose in the bloodstream. First it converts glucose into an insoluble sugar: glycogen.

Glycogen is then stored in the liver, but also in some muscles. Secondly, the liver converts excess glucose into fats. These fats are then stored in fatty tissue. These actions together bring down the level of glucose in the blood to what it was before Leon ate lunch. But what happens if Leon exercises a couple of hours after lunch - before he eats dinner?

The level of glucose in his bloodstream will drop below the normal level. Just like high levels, low levels of glucose in the bloodstream alert the pancreas. However this time, because the levels of glucose are low, the pancreas releases another hormone, called glucagon. Glucagon stops cells from taking in glucose, which means more glucose will stay in the bloodstream. Glucagon also carries instructions to the liver to start converting the stored glycogen back into glucose.

That glucose is then released into the bloodstream and can travel to the cells that need it. This process of keeping blood sugar levels constant is really important. There always needs to be enough glucose in the bloodstream because the body needs it to function. Eating regularly and making sure that your meals are nutritious will help your body keep the levels of glucose as they should be. This makes the work of insulin and glucagon much easier!