Atropine works to prevent the effects of nerve agents which can in a matter of seconds cease ALL nervous system activity in your body - very bad sh!t...
Atropine:
Competitive antagonist of acetylcholine at smooth muscle, cardiac muscle, and various glandular cells. Increases heart rate by slowing the effects of the parasympathetic nervous system while accelerating the effects of the sympathetic nervous system. Relaxes bronchial smooth muscle, thereby reducing airway resistance and increasing dead space by up to 30%. Motor activity in the stomach and small and large intestines is reduced. Salivary secretion is inhibited.
acetylcholine:
a small organic molecule liberated at nerve endings as a neurotransmitter. It is particularly important in the stimulation of muscle tissue. The transmission of an impulse to the end of the nerve causes it to release neurotransmitter molecules onto the surface of the next cell, stimulating it. After such release, the acetylcholine is quickly broken into acetate and choline, which pass back to the first cell to be recycled into acetylcholine again. The poison curare acts by blocking the transmission of acetylcholine. Some nerve gases operate by preventing the breakdown of acetylcholine causing continual stimulation of the receptor cells, which leads to intense spasms of the muscles, including the heart. Acetylcholine is often abbreviated as Ach. See nervous system.