Rib
Ribs are classed as flat bones which usually have a protective role in the body. Humans have 24 ribs, in 12 pairs. All are attached at the back to the thoracic vertebrae, and are numbered from 1–12 according to the vertebrae they attach to. The first rib is attached to thoracic vertebra 1 (T1). At the front of the body most of the ribs are joined by costal cartilages to the sternum. The ribs connect to the vertebrae with two joints, the costovertebral joints.
List of bones of the human skeleton
The human skeleton of an adult consists of 206-208 bones. It is composed of 270 bones at birth, but later decreases to 80 bones in the axial skeleton and 126 bones in the appendicular skeleton. Many small supernumerary bones, such as some sesamoid bones, are not included in this count.