The 7th, 8th and 9th pairs of ribs are called

The human rib cage consists of 7 pairs of true ribs, 3 pairs of vertebrochondral ribs and 2 pairs of floating ribs. First seven pairs of ribs are called true ribs. They ventrally connected to the sternum with the help of hyaline cartilage. The 8th, 9th and 10th pairs of ribs do not articulate directly with the sternum but join the seventh rib with the help of hyaline cartilage. These are called vertebrochondral ribs. The last two pairs (11th and 12th) of ribs are not connected ventrally and are therefore, called floating ribs.