The Joints | Science Olympiad for Class 5 PDF Download

What is a Joint?

A joint is a location in our body where two bones meet. It is a junction between two or more bones. It allows movement and provides mechanical support to the body.

Cartilage is a type of elastic tissue, which keeps the bones from rubbing against each other. Bones are held together by strong tissues called ligaments. Our body has several joints. These joints may be movable or immovable. 

Immovable Joints 

Bones are held tightly together in an immovable joint. Cartilages are not present between the joint. The bones in the skull are immovable joints. 

Movable Joints 

The joints which allow different kinds of movements are called movable joints. At joints, bones move smoothly because of a fluid which acts like a lubricant. There are four types of movable joints.

Let us discuss them in detail: 

1. Hinge Joint 

This joint is like a hinge in a door. This kind of joint only allows back and forth, i.e, they allow movement in one direction only. Hinge joints are found in the elbow, knees, fingers, toes, etc. 

2. Ball and Socket Joint 

The ball and socket joint allows the maximum movement. It is found in the hip and shoulder joints. In such a joint, one bone that ends in a ball fits into the socket of the other.

3. Pivot joint 

The joint which joins the skull to the backbone is the pivot joint. The rod-shaped end of one bone fits into the ring-type end of the other bone. In this case, the rod-shaped vertebral column (first two vertebrae) fits into a hole in the skull. This joint allows movement of our head from side by side, and up and down. 

4. Gliding joint 

This kind of joint is found between the wrist and ankle and between the two vertebrae. It allows slight movement in all directions. It helps our wrist to bend, twist and turn at each point.  

Summary