SHAPE OF THE GLOTTIS WHEN AT REST.
THE GLOTTIS DILATED.
GLOTTIS, CLOSED, AND MUSCLES CLOSING IT.
Each cord consists of a band of yellow tissue, covered by mucous membrane.
By means of the action of the muscles of the larynx that connect with the cartilages which enter into its structure, the vocal cords are so adjusted that when the muscles of expiration force the air, which is compressed in the lungs, out between these cords, their edges are set in vibration. This is the beginning of the sound which we call voice, but before it is heard in speech or song it is reinforced by the chambers of resonance.[[1]]