False ribs

Bone: False ribs
Anterior surface of sternum and costa cartilages. (False ribs are last five ribs.)
Latin	costae spuriae
Gray's	subject #28 123

The false ribs, are the five sets of ribs below the top seven true ribs. A rib is considered to be "false" if it has no direct attachment to the sternum, also known as the breast bone. Of these:

• the first three (eighth, ninth, and tenth rib) have their cartilages attached to the cartilage of the rib above (vertebro-chondral):
• the last two (eleventh rib and twelfth rib) are free at their anterior extremities and are termed floating ribs or vertebral ribs because they connect neither with the sternum nor with another rib. ^[1]. These ribs are relatively small and delicate, and are capped by a cartilaginous tip.^[2]

Ninth rib

The frontal part of the ninth rib is at the same level as the first lumbar vertebra. This level is called planum transpyloricum, since the pylorus is also at this level.^[3]

Tenth rib

The tenth rib attaches directly to the body of vertebra T10 instead of between vertebrae like the second through ninth ribs. Due to this direct attachment, vertebra T10 has a complete costal facet on its body. In the Japanese and some other people groups, the tenth rib is also usually a floating rib, lacking the cartilaginous connection to the seventh rib.^[2]

References

1. ^ Ribs. http://www1.american.edu/adonahue/k11ribs.htm. [Web]
2. ^ ^{a b} Saladin, Kenneth (2010). Anatomy and Physiology: The Unity of Form and Function. USA: The McGraw-Hill Companies, Inc.. pp. 485. ISBN 978-0-07-352569-3. 
3. ^ Bålens ytanatomi (surface anatomy). Godfried Roomans, Mats Hjortberg and Anca Dragomir. Institution for Anatomy, Uppsala. 2008.

External links

• false+ribs at eMedicine Dictionary

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.