Sternum, Anterior View

Description

Centered on the anterior thoracic wall, the sternum (breastbone) is isolated in contrast to the surrounding rib cage, with the manubrium positioned superiorly, the sternal body extending inferiorly in the midline, and the xiphoid process forming the tapered distal tip. The sternal angle (angle of Louis) is visible as a transverse ridge at the manubriosternal junction, lying just inferior to the jugular notch and medial to the anterior ends of the ribs. Costal notches along the lateral margins imply the attachments for the costal cartilages, framing the sternum between the right and left hemithoraces. Palpation and surface anatomy hinge on this anterior view. The sternal angle marks the level of the second costal cartilage, the landmark clinicians use to count ribs and intercostal spaces for auscultation, chest tube placement, and ECG lead positioning. It also approximates the T4 to T5 intervertebral disc level, a reference plane used to discuss mediastinal anatomy, including the tracheal bifurcation and the transition between superior and inferior mediastinum. Small structure, big consequences. Educationally, this asset supports gross anatomy and surface anatomy teaching in the thorax, where learners must translate bony landmarks into safe clinical actions, from choosing an intercostal space to orienting thoracic cross sections. It also fits well in surgical atlases and patient-facing perioperative materials explaining median sternotomy for cardiac surgery and the risks of sternal fracture after blunt trauma or CPR. Anatomical accuracy verified by SciePro's Medical Advisory Board.