Raven is sweeping a dusty shelf. Suddenly she sneezes. "Achoo!"
Rocket jumps. "Did you decide to sneeze?" he asks.
"No," Raven says. "It just happened. What do you notice about that?"
Nova floats closer. "Some actions happen before you have time to think," she says.
Rocket rubs his chin. "So who gave the order?"
A reflex is an automatic action. Your body does it without you thinking.
You are born with most of your reflexes.
Many reflexes protect your body.
You blink when something flies toward your eyes.
You raise your arm if a ball is thrown your way.
Coughing and sneezing are reflexes too. They clear dust out of your airways.
If you touch something too hot, your hand pulls back right away.
That happens before the "this is hot" message even reaches your brain!
A doctor may tap just below your knee with a little rubber hammer.
Your lower leg kicks out. You did not decide to kick!
The tap stretches a tendon and the thigh muscle joined to it.
A message zips to the spinal cord.
The spinal cord quickly sends a message back. It tells the thigh muscle to tighten.
This reflex helps you stay standing. It keeps your knee straight.
| Statement | True or false? |
|---|---|
| A reflex is something you plan carefully. | ? |
| Coughing is a reflex. | ? |
| Many reflexes protect your body. | ? |
| In the knee tap, the spinal cord sends a message back to the muscle. | ? |
Super noticing! Tomorrow we see how practice builds new pathways in your brain.