Science · Class 6
Body Movements
Ball-and-socket, hinge, and pivot joints; movement in fish, birds, and earthworms.
4 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Animals and humans move using bones, joints, and muscles. This chapter covers the human skeleton, types of joints, movement in snails, birds, fish, and cockroaches.
Human Skeleton
- 206 bones in adult human skeleton
- Skull protects brain; rib cage protects heart and lungs
- Backbone (vertebral column) supports upper body
- Pelvic girdle, shoulder girdle attach limbs
Types of Joints
- Ball and socket: shoulder, hip — move in all directions
- Hinge: elbow, knee — back and forth only
- Pivotal: neck — rotation
- Fixed: skull bones
- Gliding: wrist, ankle — slight sliding
Muscles and Movement
- Muscles pull on bones; bones cannot push
- Pairs of muscles work alternately (biceps/triceps)
- Cartilage cushions joints; ligaments join bones
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Joint type
Which joint allows you to rotate your head?
- 1Neck has pivotal joint between atlas and axis vertebrae
- 2Allows side-to-side and rotational movement
Answer
Pivotal joint in neck
Muscle action
How does your arm bend at the elbow?
- 1Biceps contracts and shortens
- 2Pulls forearm up
- 3Triceps relaxes
Answer
Biceps contracts; triceps relaxes
Key Points to Remember
- ✓ Earthworm moves by contraction of body muscles
- ✓ Snails move on muscular foot with slime
- ✓ Birds have hollow bones for flight
Exam Tips
- • Draw ball-and-socket and hinge joints
- • Name bones of arm and leg
- • Explain how muscles work in pairs
Practice MCQs — Body Movements
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Ball and socket joint is in: