Every organ in your body has its own brain. You won't find this in most traditional anatomy and physiology books because the professors of A and P who wrote the books weren't aware of this simple fact.
The women of the world have known at least part of the truth of this for years. For example, they might say of a man, "He thinks with his [genitalia]!" What this really means is that the brain of that organ has greater control of the individual's nervous system than do the other brains.
The modern medical community seems to think that the brain of the head (which is actually a small portion of the large snot-producing gland located behind the nose) is the only brain in the body, and they attribute many functions to that organ. Even if you include the larger snot-producing portion of this organ, it is obvious to any engineer that there isn't enough room in it to store all the memories a person will collect over the years.
The actual function of this brain is to collect the signals sent from the sense organs in the head, the eyes, the ears, the mouth (taste), and the nose (smell). It is true that in a few humans, usually very young humans, this brain is the body's lead brain. You can tell when this brain is the lead brain by the excess in snot production.
Different people have different lead brains. In the example given above, the brain in the man's sex organ served as the body's lead brain. For another man, the brain in the stomach might serve as the lead brain.
In women the most common lead brain is that of the tongue, which governs speech. In other women the brain of the heart takes this role, and they spend their days seeking impossible romance.
The lead brain can change from time to time. Many young humans, who spend much of the time between the ages of three and seven using the head brain as the lead brain, eventually come to use a different brain for the lead.
Men who grow up to be corporate executives usually use the brain of the glutimus maximus as the lead brain. You can tell because this brain is closest to the wallet. When a disgruntled worker accuses them of being unable to "...tell your butt from your brain," he or she is telling the truth.
From time to time the organs can't work out which brain should be the lead brain. This conflict can be expressed in several ways. In rare cases the various organs trade off. The conflict between them has become so severe that they rarely commuicate with each other. This way the person appears to be several different people, many of which are not aware of the existence of the others.
Far more often this conflict results in various diseases. If, for example, the stomach's brain was having a disagreement with the tongue's brain, it might send stomach acid up the esophogus trying to damage the tongue. Doctors call this acid reflux. More often the stomach's disagreement is with the brain of the glutimus maximus. In these cases the stomach will send waste in gas or liquid form which the latter brain will have to expell from the body.