Write definitions on ...... Ball and …

1. Ball and socket joints:

In the ball and socket joint, one end of the bone has a round shape like a ball which fits into a socket in the other bone.  It occurs at the shoulder joints and the hip joints.

ii. Hinge joints:

A hinge joint allows the movement of bones in only one direction, forwards and backwards. It occurs at elbow, knee, knuckles and jaw.

iii. Fixed joints:

In fixed joints, the bones are held so tightly together that they cannot move at all. These are immovable joints and provide support and strength to the body and protect the delicate organs which cannot withstand any kind of deformation. It occurs between the skull and the upper jaw.

iv. Pivotal joints:

In a pivotal joint, a cylindrical bone turns in a ring-type bone. It allows rotation around an axis. It occurs in the neck and forearm. It also occurs where our head joins the neck