Which category do the femur, tibia, and fibula belong to?

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

Answer: (A)

Long bones are bones that are longer than they are wide and have a tubular shaft with expanded ends, built to act as levers and to bear weight. The femur, tibia, and fibula fit this description perfectly: they are long, weight-bearing bones in the legs with a central shaft (diaphysis) and ends (epiphyses) that form joints with adjacent bones. This shape provides both strength and the mechanical leverage needed for movement. In contrast, short bones are roughly cube-shaped (like those in the wrists and ankles), flat bones are thin and curved (such as the sternum or skull bones) and irregular bones have varied shapes (like the vertebrae).