Science The Human Body Conceptual 7–9 yrs

How Muscles Move Bones

肌肉如何带动骨骼运动

Description

Understand that muscles work in pairs to move bones: when one muscle contracts (gets shorter and pulls), the opposite muscle relaxes, and that some muscles are voluntary (we choose to use them) while others like the heart are involuntary (they work automatically)

Mastery Evidence

✓ Demonstrate or describe how biceps and triceps work as a pair to bend and straighten the arm
✓ Explain the difference between voluntary muscles (we control them) and involuntary muscles (they work automatically)
✓ Name the heart and muscles of the digestive system as examples of involuntary muscles

Assessment Prompt

Can your child bend their arm and explain that one muscle is pulling while the other is relaxing — and that their heart muscle works without them thinking about it?