Concerning the sternum, the following is/are true:

a. The xiphoid process is the anterior border of the thoracic outlet

b. Gladiolus is the body of the sternum

c. The angle of Louis is at the level of the 2nd costal cartilage

e. The sterno-manubrial junction is at the level of T4 posteriorly

The sternum consists of 3 segments, the upper manubrium, the body or gladiolus, and the xiphoid process which ends in the rectus sheath and has no costal attachments. The xiphoid marks the anterior border of the thoracic outlet. The junction of the manibrium and body is the sternal angle or angle of Louis which corresponds to the level of T4 posteriorly and attaches to the 2nd costal cartilage anteriorly.