Abductor of vocal cords is
Abduction of vocal cords is by Posterior cricoarytenoid only. Posterior Cricoarytenoid is a triangular muscle. - Origin: Posterior surface of the lamina of the cricoid cailage. Origin is medial to inseion. - Inseion: Its fibres pass upwards and backward to the inseed into, the anterior aspect of muscular process of the arytenoid cailage. Ref: BD Chaurasia's HUMAN ANATOMY, Volume 3, 4th edition.
Thyroarytenoid
Lateral cricoarytenoid
Posterior cricoarytenoid
Cricothyroid
Head and neck