A 21 yo comes to ED after being hit by car. He had no LOC temp is 98.4, pulse is 78, resp is 26 bp is 118/70. He is alert and oriented. Physicl exam shows deformity of both femurs with ecchymosis over skin. Lower limb x ray shows multiple fractures. He is admited to hospital for treatment/observation. On day 3 he has shortnes of breath. Physical exam reveals no rashes and ndeorlogic/fundoscopic exam shows no abnormalities. O2 saturation is 40 % on room air. Chest x ray shows patchy bilateral infiltrates. Lower extremity duplex are normal. 1. What pathology do you suspect and why? 2. How is the lung damaged in this situation? 3. What cell is responsible for the pathognesis of this situation?

The main function of the respiratory system is gas exchange (O2 and CO2). Ventilation is the movement of air through the respiratory tract into (inspiration) and out of (expiration) the respiratory zone (lungs).