The basic unit of the nervous system is which of the following?

• A. Neuron
• B. Glial cell
• C. Nerve fiber
• D. Dendrite

Answer: (A)

Neurons are the basic unit of the nervous system because they are the cells that process and transmit information throughout the body. They generate electrical impulses and communicate with other neurons, muscles, or glands at synapses, enabling sensation, movement, and thought. A neuron consists of structures like dendrites that receive signals, the cell body that integrates them, and the axon that sends signals to the next cell. Glial cells provide essential support—nourishment, insulation, cleanup—but they do not carry electrical signals themselves. A nerve fiber refers to an axon or bundle of axons, and a nerve is a collection of many such fibers; neither alone is a single cell. Dendrites are parts of neurons, not the whole cellular unit.