Nerve Cells

Lesson Plan - Get It!

Audio:

In the game of Telephone, you pass messages from person to person.

Your nerve cells work in a similar fashion, passing electrical impulses to send messages throughout the body. The brain is the major organ in the nervous system, and is responsible for sending directions to body systems. These directions travel along nerve cells that have a really unique structure.

Neurons range in size, depending on the location in the body and function. All neurons are animal cells, so they do have a cell membrane that protects the cell. Inside, a cell nucleus holds DNA, and mitochondria help the cell turn food into energy. Notice the shape in the image above — it does not look like a typical animal cell! These cells have additional structures that help neurons carry out nervous system processes.

Notice the dendrites at the top of the neuron. These branches help distribute messages quickly from the brain throughout the body. Axons help move the impulse from one nerve cell to the next. The axon is surrounded by the myelin sheath, a membrane that insulates the electrical impulse as it moves down the cell. Synapses are the areas of connection between two nerve cells. This is where the message jumps across a small gap from one cell onto the next cell.

These structures make the neuron unique because they support the function of the cell to move messages quickly throughout the body.

Neurons make up the nervous system, and are found in every part of your body. They have a special structure that uses dendrites and axons to move electrical messages from the brain to your cells in other parts of your body.

• How might the function change if a neuron were damaged or destroyed?
• How do neurons move messages back to the brain?

Discuss what you have learned with a parent or teacher before moving to the Get It? section, where you will explore more about types of neurons.