The Anatomy Of The Costal Notches Of The Sternum

Description

Running along the lateral borders of the manubrium and sternal body, the costal notches appear as paired, shallow concavities that accept the costal cartilages and define the parasternal margin of the anterior thorax. The sequence typically begins superiorly at the jugular notch and clavicular notches, then tracks inferiorly to the first costal notch on the manubrium and the second at the manubriosternal junction (sternal angle), continuing down the body to the seventh near the xiphisternal junction. As the animation progresses, each notch is highlighted in order and aligned to its corresponding rib and costal cartilage, clarifying how the sternum articulates anteriorly while the ribs sweep laterally toward the vertebral column. A bony landmark you palpate daily. Clinically, these notches anchor surface anatomy: the sternal angle marks the second costal cartilage and is the standard starting point for rib counting, central line orientation, and auscultation mapping of cardiac valve areas. The animated pass from superior to inferior makes the segmental pattern easier to retain than a single frame, and it helps learners distinguish the first costal cartilage’s manubrial attachment from the shared notch for the second costal cartilage at the manubriosternal joint. The same relationships guide parasternal approaches in thoracic surgery and explain why costochondral or costosternal pain localizes where cartilage meets these cupped margins. Use this animation in gross anatomy and surface anatomy labs, in musculoskeletal radiology teaching when correlating frontal chest radiographs or CT bone windows with palpable landmarks, and in patient-facing education about chest wall pain and rib injuries. Anatomical accuracy verified by SciePro's Medical Advisory Board.