Question

The rib cage has 12 pairs of ribs. Which cartilage attaches the front ends of the first seven pairs of ribs to the sternum? What is the name of these seven sets of ribs?

Answer 1

The first seven pairs of rib bones (beginning at the top of the sternum) are called "true ribs."  They connect to the spine (by ligaments) at the back, and connect to the sternum by costal cartilage in the front.  Costal cartilage is elastic and allows the ribcage to expand during respiration.