Flexible bronchoscopy (bron-kos'ko-pi) is a visual exam of the breathing passages of the lungs (called “airways”). It is also called airway endoscopy. This test is done when it is important for your doctor to see inside the airways of your lungs, or to get samples of mucus or tissue from the lungs. Bronchoscopy involves placing a thin tube-like instrument called a bronchoscope (bron'ko-sko-p) through the nose or mouth and down into the airways of the lungs. The tube acts as a camera and is able to carry pictures back to a video screen.