Rib Cage

About the Rib Cage

The rib cage, or thoracic cage, is the bony and cartilaginous enclosure of the chest, formed by the sternum at the front, twelve pairs of ribs, their costal cartilages, and the twelve thoracic vertebrae at the back. The first seven pairs are true ribs that attach directly to the sternum through their own cartilages. Ribs eight to ten are false ribs that attach indirectly through the cartilage of the rib above, and ribs eleven and twelve are floating ribs with no front attachment. The rib cage protects the heart, lungs, and great vessels and partly shields the liver, spleen, and kidneys. It is also essential for breathing: the intercostal muscles between the ribs, together with the diaphragm, change the volume of the chest to draw air in and push it out. The cage is flexible in children and becomes stiffer with age. Rib fractures are common after chest injuries and can be painful enough to impair breathing. Variations include cervical ribs, an extra rib arising from the lowest neck vertebra.