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:
“Then he rang the bell and ordered a ham sandwich. When the maid placed the plate on the table, he deliberately looked away but as soon as the door had shut, he grabbed the sandwich with both hands, immediately soiled his fingers and chin with the hanging margin of fat and, grunting greedily, began to much.”
—Vladimir Nabokov (1899–1977)