Axial Skeleton
The Bony Thorax
The Bony Thorax
• Includes sternum, ribs, and thoracic vertebrae
• Cage protects heart, lungs, and major blood vessels
The Bony Thorax - Sternum
• Formed by fusion of three bones– Manubrium is top heart-shaped structure, includes
jugular notch– Body is middle elongated bone, fused with
manubrium at Sternal Angle– Xiphoid Process is inferior tip, fused with body at
Xiphisternal Joint
The Bony Thorax - Sternum
The Bony Thorax - Ribs
• Twelve pairs of ribs form walls of thoracic cage• Two sections of ribs:
– True ribs: first seven pairs, attached directly to sternum by costal cartilage
– False ribs: next five pairs either attached to cartilage of superior ribs or not attached anteriorly (two pairs called floating ribs)
• Intercostal spaces: between ribs, filled with muscles to aid in breathing
The Bony Thorax - Ribs