Lymphatics run over surface of the lung toward the hilum and also penetrate the lung to join the bronchial lymph vessels by passing through the inter lobar septa. This pattern of lymphatic traffic is important to consider when staging the mediastinum in patients with lung cancer.
Negative pressure results from the opposing elastic forces of chest wall and lung.
Pleural Fluid Formation and Reabsorption Fluid can enter or exit the pleural space from capillaries or lymphatics of the parietal or visceral or from interstitial spaces. Need to consider hydrostatic pressure and oncotic pressures in the pleural space, visceral and parietal pleura, and the filtration coefficient of the membrane.