Which nervous system is classified as cholinergic?

The parasympathetic nervous system is classified as cholinergic because it primarily uses acetylcholine as its neurotransmitter to communicate signals within the body. This system is part of the autonomic nervous system, which controls involuntary bodily functions. When the parasympathetic nervous system is activated, it promotes rest-and-digest activities, including decreased heart rate, increased digestion, and energy conservation. The cholinergic action is significant for its role in mediating these restorative processes, directly influencing organs such as the heart, lungs, and gastrointestinal tract.

In contrast, the sympathetic nervous system predominantly uses norepinephrine, while the somatic nervous system primarily controls voluntary movements and does not primarily utilize acetylcholine in the same way as the parasympathetic system does for its autonomic functions. The cranial nervous system is not specifically defined in terms of neurotransmitter classification and includes both sensory and motor functions involving various cranial nerves. Thus, the distinction of the parasympathetic nervous system as cholinergic is essential for understanding how different parts of the nervous system regulate bodily functions.