Pleural fluid formation with increased systemic venous pressure

Schematic representation of pleural fluid formation with increased venous pressure. An elevation in systemic venous pressure both increases filtration from the parietal pleural microvessels (the intercostal arteries, solid arrows) and decreases lymphatic drainage into the venous system (dashed open arrow). Filtration from visceral pleural microvessels (the bronchial arteries) is unaffected (dashed solid arrows). In comparison, an elevation in pulmonary venous pressure would increase filtration from the visceral pleural microvessels.