Root of neck The juctional area between the thorax and the neck ◆Boundary: anteriorly:the manubrium of the sternum posteriorly:T1 laterally:1st ribs and their costal cartilagesRoot of neck ◆The juctional area between the thorax and the neck ◆Boundary : • anteriorly: the manubrium of the sternum • posteriorly: T1 • laterally:1st ribs and their costal cartilages