Class 6 Science | Chapter 8 Body Movements

1. What are joints?

Joints are the places where two bones of our body join together. We are able to bend or rotate our body in such places.

2. Define ball and socket joints

Ball and socket joints form when the rounded edge of one bone fits into the cavity of the other bone. Such joints allow movements in all directions.

3. What type of joint joins our arm to the shoulder?

Ball and socket joint

4. Which type of joint joins our neck to head?

Pivotal joint

5. Which type of joint allows movement in forward and backward direction and also to right and left?

Pivotal joint

6. Define pivotal joint

The pivotal joint joins our neck to head. It allows us to move our head in the forward and backward direction and also to right and left.

7. What type of joint allows only a back and forth movement?

The hinge joint

8. What type of joint is present in the elbow and the knee?

Hinge joint

9. What are fixed joints?

Fixed joints are those joints where we cannot move the bones. An example of a fixed joint is the joint that joins the upper jaw to the skull.

10. What is rib cage?

Ribs join the chest bone and the back bone together to form a box. This is called rib cage. It protects internal organs like lungs and heart.

11. How are we able to bend?

We are able to bend because our backbone is made up of several small bones.

12. Which bones enclose the portion of your body below stomach?

Pelvic bones

13. What is skull?

The skull is the framework of bones that enclose the brain.

14. What is cartilage?

A cartilage is a part of the skeleton that is not as hard as bones. Unlike bones cartilage can be bent. Cartilage is present in the external ear and nose.

15. What makes the bone move?

Muscles make the bone move. They work in pairs. When muscle contracts, it pulls the bone in that direction. A muscle can only pull. It cannot push. Hence, two muscles have to work together to move a bone.

16. What is a streamlined shape?

In some living beings like fish, the head and tail are smaller than the middle portion of the body. This shape is called streamlined shape.

17. Define skeleton

The skeleton is made up of bones and cartilage. It gives shape and frame to the body and helps in movement. It protects the inner organs.

18. How does the bone move?

The alternate contractions and relaxations of two sets of muscle help the bone move.

19. How do birds fly?

Birds fly by flapping their wings. They have strong muscles and light bones.

20. How does fish swim?

When fish swim, muscles make their front part to curve to one side and the tail swings to the other side. Thus the fish form a curve. Then its head and tail quickly curve to the other side. This makes a jerk and pushes the body forward.

21. How many types of joints are in our body? Name them.

There are five types of joints in our body. They are:
Ball and socket joints
Hinge joints
Gliding joints
Pivotal joints
Fixed joints

22. What are the different parts of the skeletal system?

The different parts are:
Skull
Limb bones
Back bones
Chest bone
Shoulder bone
Hip bone