CHAPTER 1 Powerful MUSCLES A runner speeds down the track Her heart pounds Her legs push The runner's muscular system is in full gear The body's muscles make up the muscular system Without muscles people couldn't run breathe or even poop
CANADA Canon CAN 5
Types of Muscles skeletal cardiac smooth
Oo Three Kinds of Muscle Every muscle works the same way They contract then rest This action beats the heart It moves legs and arms It digests food Three types of muscles work inside the body Skeletal muscles make bones move Smooth muscles are mostly in organs Cardiac muscles make up the heart
