The 12 ribs articulate posteriorly with the 12 thoracic vertebrae of the vertebral column. Anteriorly, the 7 true ribs articulate with the sternum, or breast bone, through the costal cartilages. The cartilagenous connections permit the ribs to swivel slightly. This action helps the lungs expand more fully during inspriation.

Following the 7 true ribs are 5 false ribs. The first three false ribs articulate with the 7th true rib. They do not directly attach to the sternum. The last two false ribs ribs - floating ribs lack anterior connections to the sternum.