The femur is a classic example of which bone category?

• A. Short bones
• B. Flat bones
• C. Long bones
• D. Irregular bones

Answer: (C)

Think about how bone shape relates to function. The femur has a long, cylindrical shaft with enlarged ends, which is the defining feature of a long bone. This shape enables it to act as a strong lever for movement while bearing body weight. The shaft is mainly compact bone with a medullary cavity, and the ends form joints at the hip and knee. Short bones are roughly cube-like (e.g., wrists and ankles), flat bones are thin and curved (e.g., skull bones), and irregular bones have complex shapes (e.g., vertebrae). So the femur fits the long bone category because of its length, shaft, and lever-like role.