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Body Lab 3-5 / Week 04 / Friday
5/6
Week 04 · Heart and Blood

Friday

Move and beat
// The pump and its delivery roads
⏱ about 15 min

Friday: Move and Beat

Rocket races around the yard with his kite. When he stops, his chest is thumping.

"Did my heart get louder?" he asks.

Raven grins. "What do you notice? Did it get faster, too?"

Nova circles the kite. "Your muscles were working hard," she says. "Think about what working muscles need."

Rocket thinks. "Oxygen! And blood brings it."

Why the beat speeds up

When you run and play, your muscles need more oxygen.

So your heart beats faster. It sends more oxygen-rich blood to your muscles.

When you rest again, your heart slows back down.

Your heart is a muscle too. Being active helps keep it strong.

FAST OR SLOW?
  • Read the question.
  • Tap your answer.
You are reading quietly on the couch. Is your heart beat faster or slower than when running?
You just jumped rope for two minutes. What does your heart do?
Why does the heart beat faster when you run?

Plan a fair test

Tomorrow your family will test how moving changes a pulse.

Scientists plan a fair test first. They change only one thing.

Here we change only what you do: rest, or move.

Everything else stays the same: same wrist, same 15 seconds, same counting.

For a fair test...True or false?
We count for 15 seconds both times.?
We count at the wrist both times.?
We count for 15 seconds once and 60 seconds the other time.?
We change only one thing: resting or moving.?
WHY THIS EXERCISEKeeping everything else the same lets us see what moving really does.

Reading a bar graph

A bar graph uses bars to compare numbers.

This one shows made-up practice numbers for a pretend scientist named Tess.

A taller bar means a bigger number.

Made-up practice data for TessBeats in one minuteBar
Resting80########
After 2 minutes of jumping jacks120############
Which bar is taller: resting or jumping?
How many more beats after jumping? (120 - 80)
THE STEPS OF OUR TEST
  • ?Rest and count your pulse.
  • ?Write down the number.
  • ?Do jumping jacks for two minutes.
  • ?Count your pulse again right away.
  • ?Make a bar graph of both numbers.
WHY THIS EXERCISEWe measure at rest, then move, then measure again and graph it.
What do working muscles need more of? Type one word.
WHY THIS EXERCISEWorking muscles need more oxygen, so the heart beats faster.
Try it
Make a prediction for tomorrow.
Will a pulse be faster at rest or after moving?
Write your prediction on paper so you can check it.

You planned like a real scientist! Tomorrow is Body Lab Day. Your family gets to collect pulse data.

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