ANS

The ANS maintains homeostasis, or a balance of forces or equilibrium, for your entire body. Among other functions, it controls the rate at which your heart beats, how fast you breathe, how much saliva your mouth is making, the rate of movement of material in your gut, your ability to initiate urination, how much you are perspiring, the size of your pupils, and the degree of visible sexual excitation you might experience. Within the human brain are numerous acetylcholine pathways that infl uence the function of the cortex, hippocampus, and many other regions (see Fig. 2–1). Within these various regions, the actions of acetylcholine allow you to learn and remember, to regulate your attention and mood, and to control how well you can move