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- Use of this artwork requires proper credit to be given (Permission: Dr. Joe Muscolino. www.learnmuscles.com – photography by David Eliot)
- There are 12 pairs of ribs, left and right, for a total of 24 ribs.
- All ribs articulate with the spine posteriorly.
- Most pairs of ribs articulate with the sternum anteriorly.
- Ribs articulate with the sternum via cartilage called a costal cartilage (costal means rib).
- If a rib articulates directly with the sternum with its own costal cartilage, it is called a true rib.
- If a rib does not have its own articulation with the sternum, but instead joins the costal cartilage of another rib, it is called a false rib.
- If a rib does not articulate at all with the sternum, it is called a floating rib (floating ribs are also false).
- Ribs protect the contents within the thoracic cavity (heart, lungs, and major vessels).
NOTES:
- There are seven pairs of true ribs and five pairs of false ribs, of which two of the pairs of false ribs are floating false ribs.
- Ribs #1-7 are true ribs
- Ribs #8-10 are false ribs because they join into the costal cartilage of rib #7.
- Ribs #11-12 are false floating ribs because they do not articulate with the sternum at all (they are usually described simply as floating ribs).
Superior view of ribs #1-12, from top left to bottom right. Note the changes in the sizes of ribs.
Posterior view of a “typical rib.”
Medial view of a “typical rib.”
Anterior view of the bony thorax.
