Who reduces friction on lung surface ( I have confusion in outer pleural membrane & pleural fluid ) Share with your friends Share 1 Janice J J answered this The outer and inner pleural membrane along with pleural fluid helps in reducing friction on lung surface. 1 View Full Answer Gayathri S Nair answered this The lung is protected by layers of tissue referred to as the visceral pleura and parietal pleura; the intrapleural space contains a small amount of fluid that protects the tissue by reducing friction. 1 Shubhangi Goyen answered this Its pleural fluid. 1