The mediastinum is located between which structures?

• A. The lungs
• B. The heart
• C. The liver
• D. The brain

Answer: (A)

The mediastinum is the central space in the thoracic cavity, sitting between the two lungs. Its lateral boundaries are the lungs, with the heart and great vessels, trachea, and esophagus housed inside it. Because it lies between the lungs, that description is the most accurate location. The other options are elsewhere in the body—liver in the abdomen and brain in the cranial cavity—so they don’t define the mediastinal position.