Bony Thorax

Bony Thorax

• The sternum, ribs and thoracic vertebrae make up the bony thorax

• The bony thorax is often called the thoracic cage because it forms a protective, cone-shaped cage of slender bones around the organs of the thoracic cavity

Sternum• The sternum is a typical flat bone and the

result of the fusion of three bones: manubrium, body and xiphoid (zif’oid) process

Manubrium

Body

Xiphoid

Ribs• 12 Pairs of ribs form the walls of the thoracic

cage• The true ribs, the first 7 pairs, attach directly

to the sternum by costal cartilages• False ribs, the next 3 pairs, either attach

indirectly to the sternum or are not attached to the sternum at all

• The last 2 pairs of false ribs lack the sternal attachments, and so they are also called floating ribs