Muscles: How You Move

What You'll Learn

Muscles work in pairs to move bones. When one muscle contracts (gets shorter), the opposite muscle relaxes (gets longer). The biceps and triceps are an example of this pairing.

Key Words

digestive system
respiratory system
circulatory system

Steps

Step 1 — Read

Read and learn: Muscles work in pairs to move bones. When one muscle contracts (gets shorter), the opposite muscle relaxes (gets longer). The biceps and triceps are an example of this pairing.

Step 2 — Do

Compare your results with a partner.

Step 3 — Observe

Observe what happens and describe it in detail.

Step 4 — Record

Record your observations in your science journal.

Check Your Understanding

Question 1

1 of 3

What connects muscles to bones?