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nervous system

OLogy Series
biology
card
328

nervous system

OLogy Series
biology

You hear a buzz, and swat at a mosquito. In that fraction of a second, a series of messages just traveled along your nervous system! First, signals raced from your ear to your brain, where you processed the sound and determined a mosquito was nearby. Then your brain sent messages along the nervous system to the muscles in your arm and hand--and the pesky insect is history!

The nervous system is made of different kinds of nerves. What type carries messages about the outside world from the body to the brain?

body nerves

motor nerves

sensory nerves

Are you right?

Correct!

Sensory nerves carry messages such as pressure, pain, and temperature. Motor nerves carry messages from the brain to muscles and organs, telling them how to respond.

What is the "hub" or "control center" of the nervous system?

brain

heart

spinal cord

Are you right?

Correct!

The brain receives and interprets signals from the rest of your body, then sends signals to your body telling it what to do. The spinal cord is the main highway of the nervous system. It carries signals from the body up to the brain, and from the brain to the rest of the body.

If you stepped on a tack, you wouldn't feel the pain if you didn't have a nervous system.

Fact
or
Fiction
?

Fact

When you step on a tack, the injured nerve cells create a pain signal. This signal travels along your nerves to the part of your brain that processes the message as pain. Ouch!

Blood vessels are the building blocks of the nervous system.

Fact
or
Fiction
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Fiction

The nervous system is made of neurons. These excitable cells have long, slender branches that connect to other neurons or other parts of the body.

All messages shoot through the nervous system at the same speed.

Fact
or
Fiction
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Fiction

Some signals travel faster than others. If you pet a fluffy dog, the signal telling you the dog is soft reaches your brain 10 to 20 milliseconds before the signal that tells you it's warm!

The right side of your brain controls the right side of your body, and the left side controls the body’s left side.

Fact
or
Fiction
?

Fiction

Each half (or hemisphere) of the brain controls the opposite side of the body. That's because nerves on each side of the body connect to the opposite side of the brain.

Definition: a branching network of nerves linking your brain to every part of your body
Parts: brain, spinal cord, nerves
Cool Fact: Nerves carry signals in one direction. Some carry signals from the body to the brain. Others send messages from the brain to the body.
Cool Fact: The nervous system runs on electricity. But the levels are low. Brain signals involve less than one-tenth the voltage of an ordinary flashlight battery.

Image credits: © AMNH/E.Hamilton.