Unit 3 Ch. 3

p. 18-19

Muscles are ​ (a)   to make the bones ​ (b)   . Without muscles, ​ (c)   could not move.

• tightened
• move
• bones
• realistic
• hard
• organs

p. 20

There are about _____ muscles in our bodies.

In what ways are muscles important to us? (choose 3)

• Muscles help us run.

• Muscles help us jump.

• Muscles help us breathe.

• Muscles are not important to us.

• Muscles hold up our body.

​ (a)   muscles are ones that you can move by your own ​ (b)   .​ (c)   muscles are ones that work ​ (d)   .

• Voluntary
• will
• Involuntary
• automatically

A human stomach is an example of an ​ (a)   muscles working.

• involuntary
• voluntary

What parts of your body make your bones move?

• muscles

• bones

• air

Do the muscles in your body weight a lot or a little?

• a lot

• a little

• I don't know

Organize these options into the right categories

Groups:

(a) Voluntary

,

(b) Involuntary

• breathing

• pedaling a bike

• heart beat

• running

• sitting

• digesting food