Certified Prevention Professional (CPP) Practice Exam

What is a neurotransmitter?

1. A nerve cell involved in sensory perception

2. A "chemical messenger" produced by neurons

3. A type of hormone regulating bodily functions

4. A structural component of brain tissue

The correct answer is: A "chemical messenger" produced by neurons

A neurotransmitter is best defined as a "chemical messenger" produced by neurons. This definition highlights the primary role of neurotransmitters in the nervous system: they facilitate communication between neurons. When a neuron is activated, it releases these chemical messengers into the synapse, the gap between neurons, where they bind to receptors on the adjacent neuron. This binding initiates a response in the receiving neuron, which can either excite or inhibit further nerve impulses, playing a crucial role in many bodily functions, including mood, movement, and cognition. The other options, while related to the nervous system or bodily functions, do not accurately describe what a neurotransmitter is. For example, a nerve cell involved in sensory perception refers to neurons themselves, but it does not capture the chemical function of neurotransmitters. Hormones are different types of chemical messengers produced by the endocrine system, and while neurotransmitters and hormones may have overlapping functions in the body, they are distinct in their production and mechanisms of action. Lastly, structural components of brain tissue pertain more to the physical architecture of the brain rather than its functional biochemical communication processes.