From the options given,all the muscles are adductor of the structure shown in the Photograph (marked by black arrow) ,except:
A. Oblique Arytenoid.
B. Transverse Arytenoid.
C. Lateral cricoarytenoid.
D. Posterior cricoarytenoid.
Ans;D. Posterior cricoarytenoid
Structure shown is Vocal cords.
Intrinsic muscles of Larynx
- Divided into respiratory and the phonatory muscles (the muscles of phonation).
- The respiratory muscles move the vocal cords apart and serve breathing.
- The main respiratory muscles are the posterior cricoarytenoid muscles.
- Posterior cricoarytenoid muscles abduct and externally rotate the arytenoid cartilages, resulting in abducted vocal folds.
- The phonatory muscles move the vocal cords together and serve the production of voice. .
- The phonatory muscles are divided into adductors (lateral cricoarytenoid muscles, arytenoid muscles-transverse and oblique ) and tensors (cricothyroid muscles, thyroarytenoid muscles).