The body has developed a complex system for feeding itself. Part of this system is designed to break down the starches and sugars which are within the foods we ingest, converting them in to our body's "basic food source", glucose.
Glucose is the basic fuel which is "burned" in the mitochondria of our cells, producing heat and charging ions which in turn help produce cellular contraction and physical movement... (as when we move our fingers, hands, arms, or body).
Many organs are involved in this system. They include the Liver, Pancreas, muscle cells and fat cells, however one can not really separate any area of the body, since the entire body is affected by this process of energy use.
Normal Glucose Metabolism
In normal metabolism, the sugars and starches within the foods we eat are broken down into glucose, and are absorbed into the blood stream. This absorption causes a rise in the blood glucose level.
As the blood containing elevated glucose levels circulates, it comes into contact with the pancreas, and certain other specific parts of the pancreas, which are contained in a sub structure called the islets of Langerhans.
These other specialized parts are the alpha, beta, and delta cells, which produce particular homones, which drastically affect blood sugar levels.
When an inreased blood sugar level is sensed by the beta cells, they secrete insulin directly into the bloodstream. Insulin is a powerful hormone which allows cell membranes to change, (become more permeable to glucose), so that they allow the glucose molecule to be pulled into the cell interior, where it can be broken down into energy.
In another example, when you've just gotten done with a bunch of work, and your blood sugar level begins to fall, the other type of cell, the alpha cell, senses a low blood sugar condition, and it releases another hormone, called glucogon. Glucogon goes out into the blood stream in the same fashion as the insulin did, however, the glucogon tells the liver cells to release some of their stored sugars back into the blood stream, thus raising the blood sugar levels back into an operating range.
Abnormal Glucose Metablolism
Many things can happen to unbalance or destroy this human system of absorption and utilization of glucose. The destruction of beta cells by a virus or an auto-immune response from our own bodies, are two reasons which have so far been found for beta cell destruction in clinical studies.
When this sort of destruction occurs, it impairs the body's ability to manufacture insulin. In the case of someone with type 1, insulin-dependent diabetes, the beta cell destruction may be complete and may never be repaired by the body. In the case of type 2 diabetes, some beta cells remain, however they may not be able to keep up with the body's demand for insulin unless a low carbohydrate or complex carbohydrate diet is followed.
