The costal margin, sometimes referred to as the costal arch, is the medial margin formed by the false ribs and one true rib—specifically, from the seventh rib to the tenth rib.
Costal margin: The lower edge of the chest (thorax) formed by the bottom edge of the rib cage.
Famous quotes containing the word margin:
“Will not a tiny speck very close to our vision blot out the glory of the world, and leave only a margin by which we see the blot? I know no speck so troublesome as self.”
—George Eliot [Mary Ann (or Marian)