Insulin is a hormone made by the beta cells of the pancreas and secreted into the blood in response to rising blood glucose level. The glucose is absorbed from carbohydrates broken down by digestion in the gut and absorbed into the bloodstream. Insulin stimulates cells in the body to take up glucose for use as an energy source. Thus, when carbs are digested and broken down to yield glucose which is absorbed, the consequent rise in blood glucose stimulates release of insulin. As blood glucose rises, blood insulin follows, which in turn causes calls to absorb the glucose for energy. Excess glucose is also stored as glycogen in the liver and muscle cells under the influence of insulin.
As the blood glucose is taken up by cells the circulating level drops, and the stimulus for insulin production and release by the pancreas fades. The fall in blood glucose is followed by a fall in blood insulin until both reach their base line levels. It’s a classic biological feedback mechanism.
As well as the control of blood sugar insulin influences several other metabolic processes and may be involved in conditions such as obesity, developmental orthopaedic disease, and laminitis. The normal healthy insulin response can become blunted or reduced by over stimulation. This abnormal condition is called insulin resistance IR which in humans can lead to diabetes. IR can in turn raise the likelihood of those other disease processes.