Lymphatic drainage of the thoracic cavity follows the parenchyma, airways, and visceral pleura through hilar lymph nodes to mediastinal lymph nodes and then to the thoracic duct into the venous circulation, a pathway that governs the metastatic spread pattern of lung cancer and infection. The thoracic cavity's principal nerves—the phrenic nerve (C3–C5, innervating the diaphragm) and the intercostal nerves (providing pleural and chest wall sensation), along with vagal/sympathetic innervation of bronchial smooth muscle and mucous glands—control diaphragmatic contraction, bronchoconstriction, and mucus secretion within respiratory anatomy and physiology.
Lymphatic drainage of the thoracic cavity follows the parenchyma, airways, and visceral pleura through hilar lymph nodes to mediastinal lymph nodes and then to the thoracic duct into the venous circu…