摘要
Abstract For a long time, it was held that the contracting and extending of the cricothyreoideus could move the thyroid cartilage and cause the distance between the thyroid and the arytenoid cartilage to increase or decrease. In this way the adjustment for the tense of vocal folds was completed. 1 4 However, this opinion did not tally with the anatomy and physiology of the cricothyreoideus and failed to explain the clinical symptoms of the cricothyreoideus paralysis. In order to reexplore this muscle, we had electrophysiologic experiments on 8 dogs, and made anatomic studies on its laryngeal cartilage, muscles and joints. The results were as follows: 1) When unilateral cricothyreoideus was stimulated, the thyroid cartilage was stable and the arch of cricoid cartilage moved towards the inferior border of thyroid and deflected to the stimulated side. 2) While bilateral cricothyreoideus were stimulated at the same time, the thyroid was stable and the arch of cricoid cartilage ascented and spun upwards. 3) When unilateral or bilateral cricothyreoideus were stimulated with the slide of the cricothyroid joints being confined, the thyroid was stable and the arch of cricoid cartilage ascented and spun upwards with no deflexion. 4) Cutting off of the external branch of unilateral superior laryngeal nerve for the paralysis of the same side cricothyreoideus paralysis caused the posterior end of glottis to slant towards the paralyzed side, while the laryngeal prominence didn't deflect. 5) Institute of Medical Anatomy of Guangzhou Military Region , Guangzhou 510315, China (Yin BG, Guo JS, Tang FB, Zhang RH and Hu FL) Except for the smaller size, the morphology of the laryngeal cartilage, muscle and joint of the dogs are similar to that of human. In sum, 1) Based on the rule of muscles that the origins are more scattered and stable than the ends, the origin and end of this muscle should be exchanged for each other, i.e. it originates from the thyroid and ends at the cricoid cartilage. 2) Based on the origin and the end, this muscle should be named “thyrocricoid muscle” rather than “cricothyreoideus”. 3) The function of this muscle is not to move the thyroid but to cause the arch of cricoid cartilage to rise and fall, and the arytenoid cartilage to incline backward and reinstate alternately along with the plate of cricoid cartilage. Then, the distance between the thyroid and arytenoid cartilage would increase and decrease alternately. In this way, the adjustment of the tense of the vocal folds is achieved.
Abstract For a long time, it was held that the contracting and extending of the cricothyreoideus could move the thyroid cartilage and cause the distance between the thyroid and the arytenoid cartilage to increase or decrease. In this way the adjustment for the tense of vocal folds was completed. 1 4 However, this opinion did not tally with the anatomy and physiology of the cricothyreoideus and failed to explain the clinical symptoms of the cricothyreoideus paralysis. In order to reexplore this muscle, we had electrophysiologic experiments on 8 dogs, and made anatomic studies on its laryngeal cartilage, muscles and joints. The results were as follows: 1) When unilateral cricothyreoideus was stimulated, the thyroid cartilage was stable and the arch of cricoid cartilage moved towards the inferior border of thyroid and deflected to the stimulated side. 2) While bilateral cricothyreoideus were stimulated at the same time, the thyroid was stable and the arch of cricoid cartilage ascented and spun upwards. 3) When unilateral or bilateral cricothyreoideus were stimulated with the slide of the cricothyroid joints being confined, the thyroid was stable and the arch of cricoid cartilage ascented and spun upwards with no deflexion. 4) Cutting off of the external branch of unilateral superior laryngeal nerve for the paralysis of the same side cricothyreoideus paralysis caused the posterior end of glottis to slant towards the paralyzed side, while the laryngeal prominence didn't deflect. 5) Institute of Medical Anatomy of Guangzhou Military Region , Guangzhou 510315, China (Yin BG, Guo JS, Tang FB, Zhang RH and Hu FL) Except for the smaller size, the morphology of the laryngeal cartilage, muscle and joint of the dogs are similar to that of human. In sum, 1) Based on the rule of muscles that the origins are more scattered and stable than the ends, the origin and end of this muscle should be exchanged for each other, i.e. it originates from the thyroid and ends at the cricoid cartilage. 2) Based on the origin and the end, this muscle should be named “thyrocricoid muscle” rather than “cricothyreoideus”. 3) The function of this muscle is not to move the thyroid but to cause the arch of cricoid cartilage to rise and fall, and the arytenoid cartilage to incline backward and reinstate alternately along with the plate of cricoid cartilage. Then, the distance between the thyroid and arytenoid cartilage would increase and decrease alternately. In this way, the adjustment of the tense of the vocal folds is achieved.
