Acetylcholine is a chemical messenger in the body that plays a crucial role in transmitting signals between nerve cells. It is essential for various functions, including muscle movement, memory, and learning. When a nerve cell is activated, it releases acetylcholine, which then binds to receptors on nearby cells, allowing communication and coordination of activities. In addition to its role in the nervous system, acetylcholine is also involved in regulating the autonomic nervous system, which controls involuntary functions like heart rate and digestion. This makes acetylcholine vital for both voluntary actions, like moving your arm, and involuntary processes, such as breathing.