Which bones are located in the arms and legs?

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

Answer: (A)

Long bones are the bones of the arms and legs, shaped for length, strength, and leverage. In the limbs, the major bones—humerus in the upper arm, radius and ulna in the forearm, and the femur in the thigh, along with the tibia and fibula in the lower leg—are long bones. They have a central shaft called the diaphysis and two ends called the epiphyses, with marrow inside the central cavity for blood cell production. This design supports bearing body weight and allows powerful movement with muscle action.

Other bone types exist, but they serve different roles. Flat bones, like those of the skull, sternum, and ribs, protect organs and provide broad muscle attachment surfaces. Irregular bones, such as vertebrae, have complex shapes to support and protect structures. Short bones, like those in the wrists and ankles, are cube-shaped and provide stability and fine movement. The limbs are built mainly from long bones, while the smaller bones in the hands and feet include short bones as well.