Identify the two primary parts of the nervous system and describe the function and structure of neurons and glial cells

The nervous system is made up of neurons, specialized cells that can receive and transmit chemical or electrical signals, and glia, cells that provide support functions for the neurons by playing an information processing role that is complementary to neurons. A neuron can be compared to an electrical wire—it transmits a signal from one place to another. Glia can be compared to the workers at the electric company who make sure wires go to the right places, maintain the wires, and take down wires that are broken. Although glia have been compared to workers, recent evidence suggests that also usurp some of the signaling functions of neurons.

There is great diversity in the types of neurons and glia that are present in different parts of the nervous system. There are four major types of neurons, and they share several important cellular components.

What You’ll Learn to Do

• Differentiate between the nervous systems of different animals
• Differentiate between the central and peripheral nervous systems
• List and describe the functions of the structural components of a neuron
• List and describe the four main types of neurons
• Describe the process of neurogenesis
• Compare the functions of different types of glial cells

Learning Activities

The learning activities for this section include the following:

• Diversity of Nervous Systems
• The Central and Peripheral Nervous Systems
• Neurons
• Neurogenesis
• Glial Cells
• Self Check: Neurons and Glial Cells