Fill in the blank. The primary function of insulin is to blank the levels of blood glucose. Increase or decrease.
Blood glucose levels are regulated by hormones released from the islets of Langerhans in the pancreas, which contain both 𝛼 cells and 𝛽 cells. The 𝛼 cells release the hormone glucagon, while the 𝛽 cells release the hormone insulin. The pancreas releases these two hormones in response to changing levels of glucose in the blood. The changes are detected by the 𝛽 cells, which are equipped with glucose sensors. Together, insulin and glucagon work to keep the blood glucose at its optimum level, not too high and not too low.
So let’s review how it is that glucagon and insulin work together to regulate blood glucose. After we eat, the glucose from our food is absorbed into our bloodstream, causing our blood glucose to rise. As the blood glucose rises, insulin is released in order to help that glucose find its way into cells that can use it for energy or gets stored as glycogen in the liver and muscles for later use. In these ways, insulin helps the blood glucose to fall, since the glucose is being sent out of the blood to other locations.
As the blood glucose falls below its optimum level, the pancreas will release glucagon, which helps release the glucose stored in the form of glycogen in the liver and muscles back into the bloodstream. And as a result, the blood glucose will go back up, until it exceeds its optimal level, at which point insulin will be released again.
So insulin lowers blood glucose, and glucagon raises blood glucose levels. And by being released at just the right time, they work together to keep the blood glucose at the optimum level, not too high and not too low. So let’s return to our question. The primary function of insulin is to do what to blood glucose? Decrease.