Which of the following is not true about the structures of the respiratory system?
1) Pleural membrane surrounds and separates each lobe of the lung
2) During inhalation, the diaphragm contracts, causing the lungs to expand due to negative pressure
3) If air accumulates in the pleural space, it results in pneumothorax
4) Pneumothorax can be treated by thoracentesis
5) None of the above statements are true