False ribs are the five pairs of ribs (ribs 8-12) that do not directly connect to the sternum (breastbone). Instead, their costal cartilages (the flexible cartilage that extends from the rib bone) attach to the seventh costal cartilage, which connects to the sternum. This indirect connection to the sternum is what distinguishes them from true ribs.
The term "false" is a bit misleading, as these ribs are just as important as true ribs in protecting the vital organs within the chest cavity. The false ribs also contribute to the structural integrity of the ribcage and assist in breathing.
Here's a breakdown of the different types of ribs:
- True ribs: The first seven pairs of ribs that attach directly to the sternum.
- False ribs: The next five pairs of ribs that attach indirectly to the sternum via the seventh costal cartilage.
- Floating ribs: The last two pairs of ribs (ribs 11 and 12) that do not attach to the sternum at all.
Examples:
- The eighth rib's costal cartilage connects to the seventh costal cartilage, which in turn connects to the sternum. This makes the eighth rib a false rib.
- The eleventh and twelfth ribs are floating ribs because they don't connect to the sternum or any other ribs.
