Skeletal parts are the components of the human body that make up the skeletal system, which provides structure and support for the body. The ulnae (5 letters) are two long bones in the forearm that connect the elbow to the wrist. The ulnas (5 letters) are the two bones in the forearm that run parallel to each other and connect the elbow to the wrist. The costae (6 letters) are the ribs that form the rib cage and protect the organs in the chest cavity.