Rocket lines up stuffed animals in a long row. "The brain is the boss," he says. "But how do its orders get to my toes?"
Raven looks at the long row. "What do you notice about this line?"
Nova glides from one end to the other. "Each one could pass a note to the next," she says.
"A message relay!" Rocket cheers.
The brain cannot do its job alone. It needs nerves and the spinal cord.
Together, the brain, spinal cord and nerves make the nervous system.
The spinal cord is a long bundle of nerves. It runs down your neck and back.
It sits inside your backbone. The bones of the backbone are called vertebrae.
The vertebrae protect the spinal cord like a strong tube.
Nerves branch out from the spinal cord to every part of the body.
The nervous system is made of millions and millions of neurons (say: NUR-onz).
A neuron is a nerve cell. It is too small to see without a microscope.
Each neuron has tiny branches. The branches connect to many other neurons.
Messages pass from neuron to neuron, back and forth, between the brain and body.
| Statement | True or false? |
|---|---|
| The spinal cord runs down your neck and back. | ? |
| The nervous system has only a few neurons. | ? |
| Neurons connect to many other neurons. | ? |
| The brain can do every job with no nerves at all. | ? |
Nice relay work! Tomorrow we meet super fast actions that happen before you even think.