Human lungs. 1 and 2 make up the larynx, or voice box. 1 is thyroid cartilage, 2 is cricoid cartilage. A thin layer is held stretched from the top of the thyroid cartilage and extends to the hyoid bone, which is the only bone in the body that is not connected to another bone.
Hilgard, E. W. and W. J. V. Osterhout Agriculture for Schools of the Pacific Slope (New York, NY: The MacMillian Company, 1910)