National Academy of Sports Medicine (NASM) Certified Personal Trainer (CPT) Practice Exam

What is the functional unit of the nervous system known as?

1. Neuron

2. Dendrite

3. Axon

4. Nerve impulse

The correct answer is: Neuron

The functional unit of the nervous system is the neuron. Neurons are specialized cells that transmit information throughout the body via electrical and chemical signals. They play a crucial role in processing and transmitting sensory input, coordinating motor output, and facilitating communication between different regions of the nervous system. Each neuron consists of three main parts: the cell body, dendrites, and axon. Dendrites receive signals from other neurons, while axons send signals away from the cell body to other neurons or muscles. The ability of neurons to communicate effectively is foundational to all nervous system functions, including reflexes, thoughts, and movements. This specialization in structure and function underscores why the neuron is recognized as the primary building block of the nervous system. Other options like dendrites, axons, and nerve impulses represent components or processes associated with neurons rather than the unit itself.