Joints and Movements

 JOINTS AND MOVEMENTS

Joints are the meeting places of two bones and help in the movement of bones.

Joints give more flexibility to bone to move. The nature of movement varies with the nature of joints.

The 4 major types of skeletal joints are: 

1)PIVOT JOINT

2) HINGE JOINT

3) BALL AND SOCKET JOINT

4)GLIDING JOINT

PIVOT JOINT enables movement in different directions. It is present at the point where the first vertebra joins the skull.

HINGE JOINT enables movement in one direction alone like a hinge. Eg: elbow joint, knee joint

BALL AND SOCKET JOINT enables movement in all directions. Eg: shoulder joint and hip joint

GLIDING JOINT enables gliding movement. Eg: wrist joint, ankle joint

STRUCTURE OF A TYPICAL JOINT: 

 A typical joint has the following parts – Bone, synovial membrane, synovial fluid, cartilage, ligament and capsule.

Synovial membrane secretes synovial fluid.

Synovial fluid functions as a lubricant between the bones.

Capsule covers and protects the joint

Cartilage reduces the friction between the bones

Ligaments ensure that bones are not displaced and holds them in position.0