American Academy of Professional Coders (AAPC) Practice Exam

Which type of bone primarily provides strength and support?

1. Flat bones

2. Irregular bones

3. Long bones

4. Seasmoid bones

The correct answer is: Long bones

Long bones primarily provide strength and support due to their structural characteristics. They are typically cylindrical in shape, which allows them to bear weight and withstand significant force. The dense outer layer of long bones, called the cortical bone, provides strength, while the inner layer, known as cancellous or trabecular bone, contributes to the lightweight nature of these bones while still allowing for support. In addition to their strength, long bones serve essential functions in movement and leverage, acting as levers for muscles during physical activity. Their length and shape enable them to support the structure of the limbs effectively, facilitating both stability and movement. Flat bones, while strong, are primarily designed to protect internal organs and provide an area for muscle attachment. Irregular bones have complex shapes that suit various functions, including support and protection, but do not primarily focus on strength. Sesamoid bones are small and embedded in tendons, providing benefits like reducing friction and changing the direction of muscle forces, rather than significantly contributing to overall strength and support. Thus, long bones are the most critical in providing strength and structural support within the skeletal system.