The following muscle is an opener of the glottis

1. Muscles which abduct the vocal cords: only posterior cricoarytenoids( safety muscles of larynx) 2. Muscles which adduct the vocal cords: * lateral cricoarytenoids * transverse aenoid * cricothyroid *thyroarytenoids 3. Muscles which tense the vocal cords: cricothyroid 4.muscles which relax the vocal cords: * thyroarytenoids * vocalis 4. Muscles which close the inlet of the larynx * oblique arytenoids * aryepiglottic 5.muscles which open the inlet of larynx : Thyroepiglotticus Ref BDC volume 3; 6th edition pg 258