The costal margin is a cartilaginous arch formed by the medial margins of the cartilages of ribs 7-10. The costal margin forms an arch that begins posteroinferiorly at the 10th costal cartilage and extends in an anterosuperior direction, terminating at the costal cartilage of rib 7, where it attaches to the body of sternum. At this point of attachment the subcostal angle is formed.
The costal margin forms the lower margin of the thoracic wall. It functions to protect higher abdominal organs such as the liver as the greater part of the liver lies just below the right costal margin. The costal margin also acts as one of the attachment points for the diaphragm.
In individuals with a low body fat percentage it is possible to palpate and locate the costal margin.
|Terminology||English: Costal margin
Latin: Arcus costalis
Synonym: Costal arch
|Structure||Cartilaginous arch formed by medial margins of costal cartilages of ribs 7-10|
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Explore the structures which contribute to the formation of the costal margin with the study unit below.
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