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Body Lab 3-5 / Week 03 / Monday
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Week 03 · Muscles

Monday

More than 600 muscles
// The pullers that move you
⏱ about 15 min

Monday: More Than 600 Muscles

Rocket tries to lift a box with his new grabber arm. The arm just flops. "Bones alone cannot move!" he says.

Raven waves at him. "What do you notice? What makes my arm move?"

Nova hovers near Raven's arm. "Something under the skin pulls on the bones," she says. "What could it be?"

Rocket grins. "Muscles!"

Your muscles

You have more than 600 muscles in your body.

Muscles do everything from pumping blood to lifting a heavy backpack.

Each muscle is made of thousands of tiny fibers.

Muscles move body parts by contracting, then relaxing.

To contract means to shorten and tighten.

MUSCLE FACTS
  • Read the question.
  • Tap your answer.
About how many muscles are in your body?
What is a muscle made of?
What does contract mean?

Who gives the orders?

Your brain controls your muscles.

When you decide to move, the brain sends a signal.

The signal travels through the spinal cord and nerves to the muscle.

Then the muscle contracts, and your body part moves.

FROM IDEA TO MOVEMENT
  • Tap a card.
  • Then tap its spot.
1First
2Next
3Then
4Last
You have more than how many muscles? Type the number.
WHY THIS EXERCISEThe body has more than 600 muscles.
StatementTrue or false?
Muscles help pump blood.?
A muscle is made of one big fiber.?
The brain sends signals to muscles.?
Muscles move body parts by contracting and relaxing.?
WHY THIS EXERCISEMuscles are bundles of fibers that contract when the brain signals.
Try it
Hold your hand open. Now slowly squeeze it closed.
Open it again. Repeat three times.
Feel your lower arm while you squeeze. Something under the skin tightens!
To shorten and tighten is to ____.
The organ that controls your muscles is the ____.

Mighty muscle work! Tomorrow we learn a big muscle secret: muscles can only pull.