As in the case of fear how does thought stimlate adrenal glands? Not so much thought but the instant recognition of a threat causes the release of adrenaline. But there must be an electrical event which is recognition. EEG's show this. But there must be specialized receptors for the different bodily functions. As in the case of sexual arrousal a recogniton of a desirable object causes a restriction in the veins in the genital area causing swelling. Or the sight of a table laid out with good food and wine causes salivation.