The ULNA is a skeletal part located in the forearm and is the larger of the two bones in the lower arm. It is the BONE that runs from the elbow to the pinky side of the wrist. The RIB is another skeletal part which is a curved BONE that makes up the RIB cage. It helps protect the lungs, heart, and other organs in the chest. Lastly, the BONE is the most common skeletal part and is a hard connective tissue that forms the body's skeleton.