The axial_skeleton is divided into three sections: the skull, the vertebral_column, and the thorax.

The thorax (bony_thorax) consists of the sternum (breastbone), ribs, and thoracic vertebrae. The sternum is formed from the fusion of three bones: the manubrium, gladiolus (body), and the xiphoid_process.

The ribs form the thoracic cage. There are twelve pairs of ribs, and the first seven pair are called true_ribs because they attach directly to the sternum. The remaining five pair are known as false_ribs because they attach to the sternum either indirectly or not at all. The last two pairs, in fact, are false ribs known as floating_ribs because they completely lack sternal attachment.