So while the thyroid raises the energy level of the brain, and the whole nervous system, as a byproduct of its general awakening effect upon all the cells of the body, the pituitary probably stimulates the brain cells more directly, perhaps in the manner of caffeine or cocaine.

He would be more astounded to learn that beneath the appearances, the changes, so alarming him, there are profound alterations in the rate at which he is taking in oxygen, burning up sugar, accumulating carbon dioxide and excreting waste byproducts through the kidneys, which are responsible for them.