The force causing air to flow into the lungs during ventilation is: Decreased lung pressure Increased lung pressure Decreased lung volume Increased lung volume Infant respiratory distress syndrome is caused by: Immaturity of the alveolar capillaries The ductus arteriosus remaining open after birth, resulting in mixing of oxygenated and deoxygenated blood The lungs being too small to adequately ventilate the body Inability to produce surfactant When you hold your breath, which of the following blood gas changes first leads to the urge to breathe? rising O2 falling O2 rising CO2 falling CO2 Gas exchange occurs in which part of the respiratory system? Select ALL correct answers: Alveoli Trachea Bronchi Bronchioles .