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Body Lab 3-5 / Week 02 / Friday
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Week 02 · The Skeleton

Friday

Bone records
// The living frame that holds you up
⏱ about 15 min

Friday: Bone Records

Rocket holds up a long cardboard tube. "This is the biggest bone in my model!"

Raven holds up a tiny button. "Then what do you notice about this one? Could a bone be this small?"

Rocket blinks. "That small? No way!"

Nova hovers near Rocket's ear. "Some bones hide in surprising places," she says. "Listen closely."

Longest and smallest

The longest bone in your body is the femur.

It goes from your hip to your knee, in your thigh.

The smallest bone is the stirrup bone, deep inside the ear.

It sits behind the eardrum. It is only about 3 millimeters long.

Your lower jaw is the only bone in your head that you can move.

BONE RECORDS
  • Read the question.
  • Tap your answer.
Which is the longest bone in the body?
Where is the smallest bone in the body?
Which bone in your head can you move?

Bones in your hands

Each finger has three bones. Each thumb has two.

The middle of each hand has five bones.

Each wrist has eight small bones.

Both hands and wrists together have 54 bones!

One finger has ____ bones.
One thumb has ____ bones.
One wrist has ____ small bones.
One hand has four fingers with 3 bones each, plus a thumb with 2. How many finger and thumb bones in one hand?
WHY THIS EXERCISEThree times four is 12. Add the thumb's 2 to get 14.
Try it
Gently bend one finger. Look for the creases.
Each crease is near a joint between two bones.
Now look at your thumb. How is it different?

Strong bones

Your body cannot make calcium. It comes from the food you eat.

Calcium-rich foods include leafy greens, like spinach and collard greens.

Being active also makes bones stronger. Running, jumping and dancing all help.

Week checkTrue or false?
An adult skeleton has 206 bones.?
The femur is the smallest bone.?
Bone marrow makes blood cells.?
Running and jumping help make bones stronger.?
WHY THIS EXERCISEThe femur is the longest bone. The stirrup bone is the smallest.
HOW A SKELETON GROWS UP
  • ?The adult skeleton has 206 bones.
  • ?Some bones grow together, or fuse.
  • ?At about age 25, bones finish growing.
  • ?A newborn baby has about 300 bones.
  • ?Some soft cartilage slowly turns into bone.
WHY THIS EXERCISEAbout 300 baby bones harden and fuse into 206 adult bones.
For a grown-up
If you have questions about your child's bones, ask a doctor or nurse.

Bone champions! Tomorrow is Body Lab Day. Your family goes on a joint hunt.

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