What do neurotransmitters primarily act as within the nervous system?

Neurotransmitters primarily function as chemical messengers within the nervous system. They are released from the presynaptic neuron and travel across the synaptic cleft to bind to specific receptors on the postsynaptic neuron. This binding initiates a response in the receiving neuron, which can influence whether it will generate an action potential or not. This process is crucial for communication between neurons, enabling various functions such as muscle contraction, mood regulation, and the regulation of bodily functions.

The role of neurotransmitters as chemical messengers distinguishes them from hormones, which are produced by endocrine glands and travel through the bloodstream to target organs, and from electrical signals that are responsible for the rapid conduction of impulses along neurons. Additionally, while cell structures play a foundational role in the anatomy of the nervous system, they do not partake in the transmission of signals in the same manner as neurotransmitters.