Ace the AP Psychology Test 2026 – Unlock Your Mind’s Potential!

Neurons are indeed the building blocks of the nervous system, serving as the fundamental units that transmit information throughout the body. They are specialized cells that communicate via electrical impulses and chemical signals, enabling various functions such as sensing stimuli, processing information, and driving motor responses. This communication occurs at synapses, where neurotransmitters are released to transmit signals between neurons. The structure of a neuron includes parts like the cell body, dendrites, and axon, each playing a critical role in the process of transmitting signals.

In contrast, the other options reference concepts that do not accurately describe neurons. Psychological disorders pertain to mental health conditions that affect behavior and thinking, which is distinct from the physiological roles of neurons. Structural components of muscles are related to muscle anatomy and function, separate from the role of neurons in the nervous system. Chemical substances in the brain, such as neurotransmitters, are indeed important for neuronal function but are not the same as neurons themselves, which are the cells responsible for carrying signals. Thus, the choice that defines neurons as the building blocks of the nervous system is correct.