Both sexes produce less as they age. These hormones affect arousability by altering the threshold for sexual stimulation. They act centrally by determining the amount of change in arousal produced by a given stimulus and peripherally by determining the amount of receptor response to a stimulus. The brain controls and regulates sexual behavior in almost all animal species primarily through hormones. Man and primates differ in this role because they depend on personal experience and cultural matters, as well as hormones.
Hormones do seem to affect arousability by altering the threshold for erotic stimulation.
The pituitary, is the master endocrine gland. This gland secretes a large number of important hormones involved in the control of many bodily functions. It releases a number of hormones for other endocrine glands, which then are picked up in the blood stream. This process creates activity as a result of the information sent from the pituitary gland. Each particular gland then produces its own hormone and discharges it into the bloodstream.