Heart location and overall shape

Summary

In humans, the heart is located in the middle of the chest (thorax) within the mediastinum, between the lungs, at approximately the level of thoracic vertebrae T5–T8. It is enclosed by a double-membraned sac called the pericardium, which attaches to the mediastinum. The heart’s apex points to the left, while its base is positioned upward; the front (sternocostal) surface lies behind the sternum and rib cartilages, and the back surface lies near the vertebral column. The upper part of the heart is where major blood vessels attach, and the apex lies left of the sternum between the 4th and 5th ribs near their costal cartilage junctions. Overall, the heart has a cone-like shape that tapers downward to the apex. It is often slightly offset to the left side of the chest (levocardia), and this leftward placement is related to the heart’s stronger and larger left side. In rare congenital dextrocardia, the heart is offset to the right. Because the heart occupies space between the lungs, the left lung is typically smaller than the right and has a cardiac notch to accommodate the heart.

Key Points

• 1

  The heart is situated in the mediastinum in the middle of the thorax (around T5–T8) with the apex pointing left.

• 2

  The heart is cone-shaped: base upward and tapering to the left-sided apex; it is usually slightly left-offset (levocardia).

• 3

  The pericardium surrounds the heart and attaches to the mediastinum; the heart’s front and back surfaces relate to the sternum/rib cartilages and the vertebral column, respectively.