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:
“Everything that explains the world has in fact explained a world that does not exist, a world in which men are at the center of the human enterprise and women are at the margin “helping” them. Such a world does not exist—never has.”
—Gerda Lerner (b. 1920)