Ribs

Ribs are curved bones that together form a rib cage that surrounds the anterior portion of the thorax. Ribs are categorized as flat bones and function to protect organs in the thorax, such as the lungs and heart.

The parts of each rib can be categorized as:

In total, there are twelve pairs of ribs. The first seven pairs (ribs 1 - 7) are classified as true ribs, this means that they individually articulate with the sternum by their costal cartilages. The next five pairs (ribs 8 - 12) are classified as false ribs. Ribs 8 - 10 form the anterior costal margin and articulate with more superior costal cartilages. Meanwhile, ribs 11 and 12 are often referred to as floating ribs as they only articulate with the vertebrae and not the sternum.

Clinical Notes:

1. The first rib cannot be palpated.

2. The ribs are numbered based on the relation of the sternal angle to the second rib, following identification of the second rib, the remaining ribs are chronologically numbered.

3. A thoracotomy is the surgical opening of the thoracic wall.