Questions: How My Body Moves

Question 1

What makes your arm bend at the elbow?

• A. Your bones bend in the middle
• B. A muscle pulls on the bones at the elbow joint
• C. Your skin stretches and the arm folds
• D. Air inside your arm pushes the bones

Answer: (B)

Your bones are hard and cannot bend. The bending happens at the elbow joint, where two bones meet. A muscle in your upper arm (the bicep) tightens and pulls on the lower arm bone, which makes your arm bend. Muscles do the pulling, joints allow the bending.

Question 2

You have muscles mainly in your arms.

• T. True
• F. False

Answer: False

You have muscles all over your body — in your legs, your back, your chest, your neck, your face, and even inside your body. Your heart is a muscle. The muscles in your face let you smile and frown. You have over 600 muscles in your whole body.

Question 3

What are joints, and why does your body need them?

Model answer: Joints are the places where two bones meet. Your body needs them so that you can bend and move. Without joints, your body would be stiff and straight like a statue — you could not walk, sit, or pick things up.

Joints allow movement. Your knees, elbows, shoulders, hips, wrists, and fingers all have joints. Each joint allows a certain kind of movement — your knee bends back and forth like a door hinge, while your shoulder can move in a circle. Without joints, bones would be locked in place.