About • Absorption • Against • Aid • Aids • Air • Allows • Average • Barrier • Bone • Called • Cartilage • Cavity • Commonly • Consists • Contains • Diaphragm • Flap • Flow • Found • How • Human • Inches • Known • Located • Mainly • Many • Measures • Mucus • Muscle • Nutrients • Off • Often • Opening • Pass • Passage • Positioned • Prevent • Primarily • Production • Ranging • Rings • Situated • Smooth • Support • Swallowing • Thoracic • Typically • Where • Windpipe