What is the primary neurotransmitter for the Parasympathetic Nervous System?

The primary neurotransmitter for the Parasympathetic Nervous System is acetylcholine. This neurotransmitter plays a crucial role in facilitating communication between nerve cells, especially in the context of the parasympathetic division, which is responsible for rest-and-digest activities. When acetylcholine is released from parasympathetic nerve endings, it binds to receptors on target tissues, leading to various physiological responses such as decreased heart rate, increased gastrointestinal activity, and enhanced glandular secretions.

In contrast, other neurotransmitters like norepinephrine and epinephrine are primarily associated with the Sympathetic Nervous System, which is responsible for the fight-or-flight response. Dopamine is involved in different pathways and functions within the nervous system but does not serve as the primary neurotransmitter in the parasympathetic system. Understanding the role of acetylcholine is crucial for respiratory therapy and pharmacology, particularly in recognizing how medications may affect parasympathetic overactivity or underactivity in various clinical situations.