Question

Both of these bones are involved in ball and socket joints within the body, but the epiphysis of each that is involved in the ball and socket joint is markedly different. Discuss what visible differences you can see between the two, and provide a functional explanation for the physical difference.

Answer 1

ANSWER: The two important ball and socket joints are the glenohumeral joint and hip joint. In the glenohumeral joint the articulation is between the humerus and the scapula. The head of humerus is almost hemispherical whereas in the hip joint the articulation is between femur and the hip bone. The head of the femur forms almost two thirds of a sphere. As,by the anatomical relation the head of femur would greatly fit into the acetabulum of the hip bone. Also the head of the femur itself has a ligament attaching it to the hip bone which also provides stability to the joint. As the humerus head is a hemisphere it cannot fully fit into the glenoid cavity leaving it less stable. It must be supported by ligaments and muscle around it to provide minimal stability.