Muscles At Work

Question 1

What do muscles do?

Answer 1

Your muscles provide the force needed to move bones at joints. They can pull not push.

Question 2

What happens when a Muscle contracts?

Answer 2

It gets shorter and fatter

Question 3

What happens when a muscle relaxes?

Answer 3

It returns to its normal size

Question 4

What is an antagonistic pair of muscles?

Answer 4

When muscles work in pairs and the one contracts the other relaxes like your triceps and biceps.

Question 5

Explain how nerves help your biceps and triceps work together as an antagonistic pair of muscles:

Answer 5

Nerves carry impulses from your brain to the muscles in your arm. They tel, your biceps to contract and your triceps to relax. As your biceps shortens it pulls on the tendon that pulls up your lower arm. Your arm bends at the hinge joint at the elbow.

Question 6

What happens to your arm muscles when you put the book onto the table?

Answer 6

This time your triceps contract and your biceps relaxes to straighten your arm.