The nervous system is the

A) complete set of glands that secrete hormones into the bloodstream.
B) collection of bundled axons that form neural cables carrying information to body muscles.
C) an organism's complete set of automatic reflex responses.
D) electrochemical communication network that includes all the body's neurons.

Nervous System

The network of nerve cells and fibers that transmits nerve impulses between parts of the body, governing both voluntary actions and involuntary responses.

Electrochemical Communication

The process by which neurons communicate with each other, involving electrical signals within neurons and chemical signals (neurotransmitters) between neurons.

Neurons

Electrically excitable cells in the nervous system that process and transmit information through electrical and chemical signals.