The sternal angle (angle of Louis) is one of the most useful landmarks on the chest wall. Which of the following corresponds to this level?

• A Attachment of the first costal cartilage and the T3 vertebra
• B Xiphisternal joint and the T8 vertebra
• C Attachment of the third costal cartilage and the T6 vertebra
• D Attachment of the second costal cartilage and the T4/T5 intervertebral disc ✓

Explanation

The sternal angle marks the attachment of the second costal cartilage, the only costal cartilage that articulates at this level, and it lies opposite the T4/T5 intervertebral disc. Because the first intercostal space is hidden under the clavicle, counting begins here. It also marks the start and end of the aortic arch, the bifurcation of the trachea, and the boundary between superior and inferior mediastinum.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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