Endoscopy involves using a small camera on the end of a tube, called an endoscope, to take images of the body as it is passed along the esophagus or trachea. Upper and lower airway endoscopy involve examining the airways (trachea) and pharyngeal regions, including the guttural pouches. The endoscope is passed up one or both nostrils so that the upper airway and associated structures (epiglottis, arytenoid cartilages, guttural pouch, ethymoidturbinates) can be observed.