Kids Judge

Kids Judge Neuroscience
Saturday 13, 2004
Katherine McEllhenny
Kathleen Mee

The nervous system is the control center for your entire body! It consists of your brain, spinal cord, and a bunch of nerves that go throughout the body. The spinal cord carries information from the arms, legs, and rest of the body, and carries signals from the brain to the body. Your back is made up of 33 bones called vertebrae, 31 pairs of nerves, and 40 muscles. Your vertebrae surround your spinal cord. Your spinal cord is only as big as your pinky finger!

What are neurons?

The human body is made up of trillions of cells. The human brain alone has about 100 billion neurons! Those cells that make up the nervous system are called nerve cells, or neurons. Bundled together, they carry messages back and forth, just like telephone wires do. Sensory nerves send messages to the brain and connect to the brain through the spinal cord inside your backbone. Motor nerves carry messages back from the brain to all the muscles and glands in the body.

How neurons pass along messages

When a neuron is stimulated (excited) -- by cold, heat, touch, sound vibrations, or some other message -- it begins to produce a tiny electrical pulse. This electricity and chemical change travels the entire length of the neuron. When it gets to the finger-like points at the end of the neuron, call dendrites, it needs help getting across to the next extended finger, or dendrite. This is where chemicals come in. The electrical pulse in the cell causes the release of chemicals that carry the pulse to the next cell. This happens again, and again, and again.

There are 3 different types of neurons:

Neurons are the oldest and largest cells in the body. You have many of these neurons for your whole life. Neurons come in many different shapes and sizes. Some of the smallest neurons have cell bodies that are only 4 microns wide. Some of the biggest neurons have cell bodies that are up to 100 microns wide (Remember -- 1 micron equals one thousandth of a millimeter!!!).

To find out the longest neuron in your body:

Take a piece of ribbon and hold the bottom of it under your big toe.
Bring the ribbon up the back of your heel and all the way to the base of your neck.
Cut the ribbon at the base of your neck -- This is how long your longest neuron is!!!

Materials:
A Partner
Ribbon
Scissors

For more information:
Home -- Kids Judge Neuroscience 2004
Neuroscience for Kids
The Nervous System