Question

What is a ball and socket joint?

Answer 1

Hint: Joints are structural arrangements where two bones articulate i.e., meet each other. The joints are essential for the movement of different skeletal structures i.e., all the bones present in the body produce movement due to the movement of these joints. Locomotory movements occur due to these joints, where these act as lever or fulcrum.

Complete answer:
Joints are classified into three types namely Fibrous joint , Cartilaginous joint , and synovial joint.
Ball and socket joint is a kind of synovial joint
Synovial or Free Movable or Diarthrotic Joints:-
Synovial joints are freely movable joints and these joints allow movement in one or more directions. The bones of these joints are covered by a membrane called synovial membrane. Inside the membrane and between the two connecting surfaces of the bone, a synovial cavity is present between these two surfaces This cavity is filled with synovial fluid that acts as a lubricant which nourishes the bones with nutrients and also acts as a cushion to absorb shocks. The fluid helps in movement of bones in all possible directions and also provides stability to the joint. Both the ends of the bones forming the joint is covered by hyaline cartilage called articular cartilage. It prevents the ends of the bones from being separated.
 

Ball and socket joint:
Ball and socket joint is the most free joint of all joints.
It shows movements in different directions.
The articulate end of one bone is in the shape of a ball whereas the end of the other bone is in the shape of a cup.
The ball of one bone is fitted into the socket of the other bone e.g. shoulder joint and hip joint.

Note: When movements are produced, the bones act as levers and joints act as fulcrum. Lever is a fixed rigid rod that moves around a fixed point known as fulcrum. When twisting of joints occurs but joints do not get displaced it is termed as sprain. It causes damage to ligaments.