Conchae are shell-shaped structures composed of bone, blood vessels, and soft tissue, located on the inner walls of the nasal passages. Their primary functions are to warm, humidify, and filter inhaled air. There are generally three main types of conchae: inferior, middle, and superior. For various reasons, conchae can enlarge; this condition is known as concha hypertrophy or, commonly, enlargement of nasal turbinates.