cricothyroid muscle

Introduction

Intrinsic laryngeal muscle. Antagonist is the thyroarytenoid muscle.

Origin

anterior surface of the arch of the thyroid

Insertion

• the anterior (straight) part passes upward to the ala of the thyroid
• the posterior (oblique) part passes laterally & upward to the inferior horn of the thyroid

Action

• pulls anterior aspects of the cricoid & thyroid cartilages together
• rotates the superior part of the cricoid & arytenoid cartilages posteriorly
• causes vocal cords to tense, increasing the pitch of the voice

Innervation

• external laryngeal branch of the superior laryngeal nerve (branch of vagus nerve, CN X)

More general terms

• skeletal muscle (voluntary muscle)