Neurons: an overview

nerves-1An image showing the basic neuron types: unipolar (top), bipolar (middle), multipolar (bottom)

Neurons are the functional building blocks of the nervous system. They communicate with each other to transmit information and coordinate activity throughout the body.

A typical neuron has three main parts: 

The cell body contains the nucleus and other organelles needed for metabolism, growth, and division.Dendrites are branches that receive signals from other neurons whereas axons carry electrochemical signals away from the cell body toward their targets.These parts work together to send messages through electrical and chemical signals.

Based on the amount of dendrites and axons, there are three types of neurons:

  • Multipolar neurons, which have one axon and multiple dendrites
  • Bipolar neurons, with a single axon and a single dendrite
  • Unipolar, which have no dendrites and possess a single axon. 
  • Pseudounipolar neurons, which have a single axon that ramifies into a dendritic and axonic process.

The majority of human neurons are multipolar.

Learn the anatomy and functions of the nervous system with the interactive diagrams below, or upgrade your knowledge with advanced quizzes and video tutorials.