Question

Which type of rib lacks an attachment to the sternum?

1) True rib
2) False rib
3) Floating rib
4) None of the above

Answer 1

The 3. floating ribs, which are ribs 11 and 12, lack any attachment to the sternum and are not connected to the costal cartilage of another rib.

Step-by-step explanation:

The type of rib that lacks an attachment to the sternum is the floating rib. The floating ribs are the 11th and 12th ribs, and they do not attach to the sternum or to the costal cartilage of another rib. In contrast, true ribs (ribs 1-7) attach directly to the sternum via their costal cartilage, while false ribs (ribs 8-10) attach to the sternum indirectly by attaching to the cartilage of the next higher rib. The false ribs comprise ribs 8 through 12, but only ribs 11 and 12 are the floating ribs that completely lack sternal attachment and end within the musculature of the lateral abdominal wall.

Of the ribs, the type that lacks an attachment to the sternum is the floating rib. Floating ribs, specifically ribs 11 and 12, are short ribs that do not attach to the sternum or to another rib. Instead, their small costal cartilages terminate within the musculature of the lateral abdominal wall.The floating ribs, which are ribs 11 and 12, lack any attachment to the sternum and are not connected to the costal cartilage of another rib.