Video Transcript
What is the main hormone released
when blood glucose is too high?
You may recall that the
carbohydrates in our food are broken down into glucose by enzymes of the digestive
system. This glucose is then absorbed into
the blood from the small intestine so it can be transported all around the body. Body tissues require glucose for
cellular respiration to release energy in the form of ATP. It is, therefore, important that
the concentration of glucose in the blood is maintained at an optimum level.
Sometimes we will consume more
carbohydrates than are needed to match our body’s energy requirement. When this happens, the
concentration of glucose in the blood rises above the optimum level. This high blood glucose level is
detected by 𝛽 cells of the pancreas, which respond by secreting insulin into the
blood.
Insulin is a protein hormone which
travels in the blood to target cells of the liver, muscles, and fat. The effect of insulin is to cause
its target cells to take up glucose from the blood and convert it into glycogen for
storage. Consequently, the blood glucose
concentration falls back down to its optimum level. Although this process is usually
very effective, it does not always work correctly.
If someone has diabetes, they
either cannot produce insulin or their body stops responding to insulin. This means their blood glucose
level remains too high, which over time can cause damage to their blood vessels. Thankfully, diabetes can usually be
treated with insulin injections or lifestyle changes.
We have therefore determined that
the main hormone released when blood glucose is too high is insulin.
