Why upper head of humerus is an example of compound epiphysis?

The upper head of the humerus is considered a compound epiphysis because it consists of multiple ossification centers that contribute to its development. This area includes both the articular cartilage surface for the shoulder joint and the surrounding growth plates. The presence of distinct regions for joint function and growth makes it a complex structure essential for the joint's mobility and stability. Additionally, the compound nature allows for better adaptation and distribution of forces during arm movements.