Question

How many ribs do not attach directly to the sternum?

a) 2 pairs
b) 5 pairs
c) 7 pairs
d) 10 pairs

Answer 1

There are 5 pairs of ribs that do not attach directly to the sternum; ribs 8-10 are termed false ribs, attaching indirectly, and ribs 11-12 are floating ribs, attaching to abdominal wall muscles.

So, the correct answer is b) 5 pair.

Step-by-step explanation:

In human anatomy, there are 5 pairs of ribs that do not attach directly to the sternum. These are known as the false ribs and are categorized as ribs numbers 8 through 12. Out of these, ribs 8-10 are anchored via their costal cartilage to the cartilage of the rib just above them.
Specifically, rib 10 is connected to rib 9, and rib 9 to rib 8, with rib 8 attaching to rib 7. The remaining two ribs, ribs 11 and 12, are referred to as floating ribs. These do not attach to the sternum or the ribs above, but their small costal cartilages terminate in the muscles of the lateral abdominal wall.

So, the correct answer is b) 5 pair.