The ribs have twelve pairs - their primary role is to provide structural support and protect internal organs and nerves. The intercostal muscles support these ribs to provide more protection.
The initial seven pairs (also called true ribs) are attached to the sternum. The remaining five pairs (from eight to twelve) are called false ribs, while the last two ribs are deemed floating ribs because they are not attached to the sternum. True ribs are directly attached to the sternum. The false ribs are indirectly connected to the sternum.
Rib fractures are the most common rib injuries. Rib fractures can cause respiratory problems, atelectasis, pneumonia or other serious conditions. Vehicle accidents and athletic activities may often cause serious rib fractures.