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Body Lab 3-5 / Week 09 / Friday
5/6
Week 09 · Ears, Hearing and Balance

Friday

The balance team
// Good vibrations and a steady body
⏱ about 15 min

Friday: The Balance Team

Rocket spins in a circle five times and stops. The room keeps whirling. "Whoa! Why is everything still spinning?"

Raven steadies him. "What do you notice? You stopped, but your body feels like you are moving."

Nova hovers nearby. "Something in your inner ear keeps moving after you stop," she says. "Think of a sloshing cup."

Three tiny tubes

Next to the cochlea are the semicircular canals.

They look like three tiny tubes joined together.

The tubes are filled with fluid and lined with tiny hairs.

When your head moves, the fluid sloshes and moves the hairs.

The hairs send signals along a nerve to your brain.

Your brain then tells your muscles how to keep you balanced.

Why spinning makes you dizzy

When you spin and stop, the fluid keeps sloshing for a while.

Your brain gets the idea you are still spinning, even though you stopped.

When the fluid stops moving, the dizzy feeling goes away.

A whole balance team

Your inner ear is not the only balance helper.

Your brain also uses signals from your eyes.

It uses signals from the muscles and touch sensors in your legs too.

The cerebellum, from Week 7, helps put it all together.

HOW THE CANALS HELP YOU BALANCE
  • ?Your head moves.
  • ?Fluid in the canals sloshes.
  • ?The brain tells your muscles how to stay balanced.
  • ?The fluid moves the tiny hairs.
  • ?The hairs send signals to the brain.
WHY THIS EXERCISEThe inner ear, nerves, brain and muscles work as one balance system.
BALANCE CHECK
  • Read the question.
  • Tap your answer.
What fills the semicircular canals?
Why do you feel dizzy right after spinning?
Which body parts send balance signals to the brain?
StatementTrue or false?
There are three semicircular canals in each inner ear.?
The canals are lined with tiny hairs.?
The dizzy feeling lasts forever after spinning.?
Your eyes help you balance.?
WHY THIS EXERCISEThe dizzy feeling fades when the fluid settles, and eyes help balance too.
The balance tubes are called the semicircular ____.
After you spin, the ____ in the tubes keeps moving.
Which part of the brain from Week 7 helps with balance?
WHY THIS EXERCISEThe cerebellum controls balance and smooth movement.

Take care of your ears

  • Keep the volume low on headphones and speakers.
  • Wear earplugs or earmuffs near very loud noises.
  • Keep cotton swabs and fingers out of your ears.
Try it
Fill a clear cup halfway with water.
Swirl it gently, then set it down and watch.
The water keeps swirling after the cup stops. That is like your balance fluid!
Safety first
Use a plastic cup. Swirl slowly so nothing spills.
Wipe up any drips so nobody slips.

Steady work, balance scientist! Tomorrow is Body Lab Day. Get ready for balance tests with your family.

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