Which statement correctly describes true, false, and floating ribs?

• A. Floating ribs (11-12) do not attach anteriorly.
• B. False ribs attach directly to the sternum.
• C. True ribs attach indirectly to the sternum via cartilage.
• D. True ribs attach directly to the sternum via costal cartilage; false ribs attach indirectly (8-10) via cartilage to cartilage; floating ribs do not attach anteriorly.

Answer: (D)

Ribs are grouped by how their costal cartilage connects to the sternum. True ribs (the first seven) attach directly to the sternum through their own costal cartilage. False ribs (the eighth through the tenth) don’t connect directly to the sternum; instead, their cartilage joins the cartilage of the rib above, creating an indirect path to the sternum. Floating ribs (the eleventh and twelfth) have no anterior attachment to the sternum at all and end within the abdominal musculature, only attaching posteriorly. This combination—true ribs attaching directly to the sternum, false ribs attaching indirectly via cartilage, and floating ribs lacking anterior attachment—best describes the relationships.