Editing Rib (section)

===Rib cage===
{{Main|Rib cage}}
[[Image:Ribs labeled.png|thumb|left|200px|[[X-ray]] image of human chest, with ribs labelled]]
The first seven sets of ribs, known as "[[true ribs]]", are attached to the [[sternum]] by the [[costal cartilage]]s. The first rib is unique and easier to distinguish than other ribs. It is a short, flat, C-shaped bone, and attaches to the manubrium.<ref>{{Citation|last1=Sly|first1=Peter D.|title=Chapter 7 - Applied Clinical Respiratory Physiology|date=2008-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780323040488500116|work=Pediatric Respiratory Medicine (Second Edition)|pages=73–88|editor-last=Taussig|editor-first=Lynn M.|place=Philadelphia|publisher=Mosby|language=en|doi=10.1016/b978-032304048-8.50011-6|isbn=978-0-323-04048-8|access-date=2020-11-03|last2=Collins|first2=Rachel A.|editor2-last=Landau|editor2-first=Louis I.}}</ref> The vertebral attachment can be found just below the [[neck]] at the first thoracic vertebra, and the majority of this bone can be found above the level of the [[clavicle]]. Ribs 2 through 7 then become longer and less curved as they progress downwards.<ref name="Saladin, K. S. 2010">Saladin, K. S. (2010). Anatomy and Physiology: The Unity of Form and Function (5th ed.). New York, NY: McGraw-Hill.</ref> The following five sets are known as "[[false ribs]]", three of these sharing a common cartilaginous connection to the sternum, while the last two (eleventh and twelfth ribs) are termed [[floating rib]]s.<ref name=":0" /> They are attached to the [[vertebrae]] only, and not to the sternum or cartilage coming off of the sternum. 

In general, human ribs increase in length from ribs 1 through 7 and decrease in length again through rib 12.  Along with this change in size, the ribs become progressively oblique (slanted) from ribs 1 through 9, then less slanted through rib 12.<ref name="Saladin, K. S. 2010"/> 

The rib cage is separated from the lower abdomen by the [[thoracic diaphragm]] which controls breathing. When the diaphragm contracts, the thoracic cavity is expanded, reducing intra-thoracic pressure and drawing air into the lungs. This happens through one of two actions (or a mix of the two): when the lower ribs the diaphragm connects to are stabilized by muscles and the central tendon is mobile, when the muscle contracts the central tendon is drawn down, compressing the cavity underneath and expanding the thoracic cavity downward. When the central tendon is stabilized and the lower ribs are mobile, a contraction of the diaphragm elevates the ribs, which works in conjunction with other muscles to expand the thoracic indent upward.