Which nerve innervates the mediastinal pleura?

• A. Phrenic nerve
• B. Intercostal nerves
• C. Vagus nerve
• D. Glossopharyngeal nerve

Answer: (A)

The mediastinal pleura is innervated by somatic fibers carried in the phrenic nerve. The phrenic nerve runs through the thorax and provides sensory innervation to the central diaphragmatic and mediastinal portions of the pleura, as well as motor to the diaphragm. This somatic innervation explains why pain from this region is often felt in the shoulder area supplied by the same nerve roots (C3–C5).

Intercostal nerves supply the costal and peripheral diaphragmatic pleura, so they don’t primarily innervate the mediastinal pleura. The vagus nerve provides parasympathetic motor and sensory innervation to thoracic viscera but not the somatic sensory innervation of the mediastinal pleura. The glossopharyngeal nerve has no thoracic pleural innervation.