Ribs
We all have 24 ribs, 12 on each side. All ribs articulate in the back to the thoracic vertebrae, and to the sternum in front (except ribs 11 and 12). The first 7 (from top to bottom) are true ribs, as they connect directly from the thoracic vertebrae to the sternum via cartilage (called costal cartilage). Ribs 8, 9, and 10 are called false ribs as they connect to the cartilage of the 7th rib, and not directly to the sternum. Ribs 11 and 12 are called floating ribs because they don't articulate with anything in the front like the first 10 ribs do.
Sternum
The sternum is more commonly called the breastbone. It is composed of 3 bones that typically fuse together in adulthood. They are the Manubrium, the Body and the Xiphoid process.
