Which nerve provides sensory innervation to the fibrous pericardium?

Which nerve provides sensory innervation to the fibrous pericardium?

• A. Vagus nerve
• B. Sympathetic trunk
• C. Glossopharyngeal nerve
• D. Phrenic nerve

Answer: (D)

The fibrous pericardium has somatic sensory fibers carried by the phrenic nerve. The phrenic nerve, arising from C3–C5, travels through the mediastinum and supplies the fibrous pericardium and the parietal layer of the serous pericardium with sensory input. This arrangement explains why pericarditis pain can be referred to the shoulder area via C3–C5 dermatomes. The vagus and sympathetic trunk mainly provide autonomic innervation to the heart itself (visceral pericardium) rather than the fibrous layer, and the glossopharyngeal nerve does not supply the pericardium.

The fibrous pericardium has somatic sensory fibers carried by the phrenic nerve. The phrenic nerve, arising from C3–C5, travels through the mediastinum and supplies the fibrous pericardium and the parietal layer of the serous pericardium with sensory input. This arrangement explains why pericarditis pain can be referred to the shoulder area via C3–C5 dermatomes. The vagus and sympathetic trunk mainly provide autonomic innervation to the heart itself (visceral pericardium) rather than the fibrous layer, and the glossopharyngeal nerve does not supply the pericardium.