Rib
Ribs are classed as flat bones which usually have a protective role in the body. Humans have 24 ribs, in 12 pairs. All are attached at the back to the thoracic vertebrae, and are numbered from 1–12 according to the vertebrae they attach to. The first rib is attached to thoracic vertebra 1 (T1). At the front of the body most of the ribs are joined by costal cartilages to the sternum. The ribs connect to the vertebrae with two joints, the costovertebral joints.
Short ribs
The "serratus ventralis" muscle defines the area in the beef carcass from where short ribs come, and is the preferred muscle tissue for short ribs. This muscle originates near the second rib, and covers most of the rib cage. In the chuck area (second through fifth ribs), the muscle is much thicker. Moving toward the rump, the "serratus ventralis" becomes less dense, and may not cover the entire rib. Outside of the chuck, the "serratus ventralis" covers the entire rib with a degree of thickness only in the plate area. Over ribs nine through 12, the "serratus ventralis" is too thin to properly create a true short rib, and meat here is usually turned into a "Royal short rib" or else stripped from the bone and used for ground beef.