Which statement is true about mesocardia?

• A. The heart lies in the midline with apex pointing inferiorly
• B. The heart is on the left side with apex pointing upward
• C. The heart lies entirely on the right side
• D. The heart is located outside the thoracic cavity

Answer: (A)

Mesocardia describes a heart that is located in the middle of the chest, not shifted to either side. In this central position, the heart’s long axis is typically vertical, so the apex points downward toward the diaphragm. This downward/inferior orientation of the apex, with the heart centered in the chest, is what the true statement conveys. It distinguishes mesocardia from normal anatomy (heart primarily on the left with the apex pointing leftward), from dextrocardia (heart on the right), and from the idea of the heart being outside the thoracic cavity.