Don’t get the wrong idea about how to move the cricothyroid articulation…
We have already discussed and know that a high-pitched or loud voice is achieved by moving the cricothyroid articulation.
Many books I have seen imply that vocalization of the cricoid cartilage bows when vocalizing.
However, this is wrong. The cricoid cartilage is actually moved up. This occurs by the moving of the pendant moiety on the cricothyroid muscle.
The cricoid cartilage and the thyroid cartilage are suspended by [A]the stylopharyngeus muscle and[B] the stylohyoid muscle. (Please see the bottom figure)
Therefore, you would expect the thyroid cartilage to slightly move back, because the soft issue extends.
Please be aware when reading any book that states that, “the thyroid cartilage goes down when vocalizing high-pitched registers.” – Because that statement is incorrect.
The vocal chord is composed of twin infoldings of mucous membranes stretched horizontally, from back to front, across the larynx. They vibrate, modulating the flow of air being expelled from the lungs during phonation. Sound is not made by metal or wood like a machine, or instrument.
**I sketched the above figures without the glenoid cavity of cricoid cartilage because it is easier to see how to move the cricothyroid articulation**
Note: Validating proper palpation:
The thyroid cartilage and the cricoid cartilage are located in the front. Hold the edge of the thyroid cartilage by the left finger and put the right finger under the cricoid cartilage, then open maximally. Figure 1 : Opened minimally Figure 2: Shows the status of the joint position, movement, and the vocal cord of expansion as well as contraction.
The blue circle is the movement range of cricothyroid articulation.
The green arrow is the orbit of movement.
The red point is the laryngeal prominence (Known as the Adam’s Apple)