costal margin(redirected from arcus costarum)
that portion of the inferior aperture of the thorax formed by the articulated cartilages of the seventh to tenth (that is, false) ribs.
Farlex Partner Medical Dictionary © Farlex 2012
The lower (abdominal) border of the front of the rib cage formed by the costal cartilages of ribs 7 to 10.
See also: margin
Medical Dictionary, © 2009 Farlex and Partners