The Anatomy Of The Manubrium Of The Sternum

Description

Framed in anterior thoracic orientation, the animation centers on the manubrium sterni, the trapezoidal superior segment of the sternum positioned superior to the body of the sternum (gladiolus) at the manubriosternal junction. The suprasternal (jugular) notch crowns its superior border, while the paired clavicular notches sit superolaterally to receive the medial ends of the clavicles at the sternoclavicular joints. Along the lateral margins, the costal notches for the first costal cartilages and the superior demifacets for the second costal cartilages come into view as the sequence rotates and settles into orthogonal angles. The sternal angle (angle of Louis) is emphasized as the manubrium and sternal body meet in slight anterior angulation. Surface anatomy and radiographic landmarks in the upper chest depend on correctly locating the manubrium. The sternal angle marks the level of the second costal cartilage, a standard counting point for ribs and intercostal spaces, and it aligns with the T4 to T5 intervertebral disc plane used to approximate the aortic arch and the tracheal bifurcation (carina). This animated rotation clarifies why the manubrium sits obliquely on the anterior thoracic wall and how the clavicular notches and first rib attachments bracket the thoracic inlet, details that often get flattened in static views. A short but clear segment. It makes the manubriosternal step-off easy to appreciate. Use this asset in gross anatomy teaching of the thoracic cage, osteology labs, and clinical skills modules that teach rib counting, chest tube site localization, and cardiothoracic surface landmarks. It also fits well in surgical and emergency medicine publications discussing median sternotomy approach landmarks, sternoclavicular joint injury, or manubrial fracture patterns after blunt trauma. Anatomical accuracy verified by SciePro's Medical Advisory Board.