What is Insulin?
Insulin is a hormone secreted by your pancreas. It helps transport the glucose in your blood, or blood sugar, into your cells where the sugar is converted into fuel. Glucose comes from the food we eat and is necessary to provide energy for our bodies. We always have some dissolved glucose in our blood. However, without insulin, the glucose would build up to dangerous levels. High levels of blood glucose can cause damage to our heart, eyes, kidneys, nerves and other parts of our bodies. Lacking insulin, our cells would not be able to receive the glucose from our blood and we would not have any energy to live.
Physiologic Effects
Food is digested and broken down into simpler components your body can use such as glucose. The glucose is then absorbed into your blood stream. High concentrations of blood glucose are a signal for your body to release insulin.
One of the main effects of insulin is to decrease the concentration of glucose in the blood. It does this by stimulating your cells to take in, use and store glucose. Insulin is needed to help transport the glucose through the protective cell membrane. Cells have special receptors on the outside of their membranes that insulin can bind to. When insulin binds to a cell, it sends a chemical signal to stimulate the cell to send its glucose transporters to the membrane and allow the glucose inside. Think of the cell membrane as a locked door and insulin as the key to unlock it and allow the glucose entry.
Another function of insulin is to stimulate the liver to store glucose as glycogen, the form in which the body banks glucose for later use. When blood glucose is abundant, insulin activates several enzymes within the liver that "tell" it to store glycogen for later use.
Diabetes and Insulin
When the body does not make insulin or the cells do not respond appropriately to insulin, diabetes results. People with type I diabetes need to take insulin shots r to use and store the glucose from their food because their pancreas either produces very little insulin or none at all. Type II diabetics make enough insulin, but their bodies do not respond well to it. People with type II diabetes may have to take diabetes pills, a medication to keep glucose levels on target, or additional insulin.
There are more than 20 different kinds of insulin sold in the United States. It is mainly made in a lab (synthetic) or comes from animals such as pigs. People take insulin via injections, injection jets which uses air to inject insulin instead of a needle or insulin pumps. An insulin pump is a small machine worn outside the body. It is connected to a tube with a small needle that is inserted under the skin and pumps insulin into the body over the course of several days.
