the center cut, or ribs 10 through 12
Twelve pairs of ribs are connected to sternum in front and also connected to thoracic vertebrae posteriorly. Together these ribs make a cage called rib cage and enclose some internal organs.
typically it has 24 human
The ribs that are not attached to sternum (11th and 12th pair of ribs) are called floating ribs.
Because the 24 ribs (12 pairs) have the resemblance of a cage structure; hence, the name "rib cage".