Which among the following is the structural and functional unit of the neural system?

The neural system monitors and regulates the functions of the body. It comprises the brain, spinal cord, and nerve cells or neurons. 

Neurons make up the nervous tissue and are the structural and functional units of the neural system. They are specialized for being stimulated to transmit stimulus from one to another part of the body rapidly.

A neuron consists of a cell body called cyton, branched processes called dendrites that carry impulses toward the nerve cell body, and axons that carry impulses away from the cell body.