Which statement accurately describes the rib arrangement in relation to the sternum?

• A. 12 pairs. 10 attached to the sternum and two connected to the sternum by cartilage
• B. 10 pairs attached directly to the sternum
• C. 14 pairs, all connected to the sternum by cartilage
• D. 24 ribs, none attached to the sternum

Answer: (A)

Ribs relate to the sternum in three groups. Seven ribs (the true ribs) attach directly to the sternum through their costal cartilage. Three ribs (the false ribs) do not attach directly to the sternum; instead their cartilage joins the cartilage of the rib above, producing an indirect connection to the sternum. The remaining two ribs (the floating ribs) do not attach to the sternum at all. In total, there are 12 rib pairs.

So, while the count of ribs is correct, the description of how many attach directly to the sternum is not. Only seven ribs attach directly to the sternum; the others connect indirectly via cartilage or not at all. This highlights how the sternum serves as the direct anchor for the upper ribs, with lower ribs joining through cartilage or not at all.