One of the brain regions that the amygdala connects to is the hypothalamus. This important structure is involved with motivational drives such as hunger, sex, and thirst and also serves as a coordinator for the physiological centers of the brain. The hypothalamus is the master control center for the autonomic nervous system. This whole body system gears the body up for action by mobilizing the cardiovascular, respiratory, muscular, and gastro-intestinal systems.

The work of the autonomic nervous system is evident when we feel emotionally aroused. Our heart beats faster, we start to sweat, our stomach churns, and our breath grows rapid and shallow. (More specifically, this is the work of the sympathetic nervous system, which speeds us up. The parasympathetic nervous system slows us down.) The hypothalamus activates the autonomic nervous system in two major ways. The first is the more traditional route of synaptic connections between neurons. The second is through the release of hormones, free-floating chemical messengers that largely travel through the blood stream.