1b. Muscles of Larynx

Question 1

cricothyroid m.

Answer 1

• Origin: anterolateral part of cricoid cartilage
• Insertion: inferior margin and inferior horn of thyroid cartilage
• Innervation: external laryngeal n. (CNX)
• Function: stretches and tenses vocal ligament

Question 2

thyro-arytenoid m.

Answer 2

• Origin: lower 1/2 posterior aspectof angle of thyroid laminae and cricothyroid ligament
• Insertion: anterolateral arytenoid surface
• Innervation: inferior laryngeal n. (terminal part of recurrent laryngeal n. from CN X)
• Function: relaxes vocal ligament

Question 3

posterior crico-arytenoid m.

Answer 3

• Origin: posterior surface of lamina of cricoid cartilage
• Insertion: voal process of arytenoid cartilage
• Innervation: inferior laryngeal n. (terminal part of recurrent laryngeal n. from CN X)
• Function: abducts vocal folds

Question 4

lateral crico-arytenoid m.

Answer 4

• Origin: arch of cricoid cartilage
• Insertion: vocal process of arytenoid cartilage
• Innervation: inferior laryngeal n. (terminal part of recurrent laryngeal n. from CN X)
• Function: adducts vocal foldings (interligamentous portion)

Question 5

transverse and oblique arytenoids m.

Answer 5

• Insertion: one arytenoid cartilage
• Origin: contralateral arytenoid cartilage
• Innervation: inferior laryngeal n. (terminal part of recurrent laryngeal n. from CN X)
• Function: adduct arytenoid cartilages (adducting intercartilaginous portion of vocal folds, closing psterior rima glottidis)

Question 6

vocalis m.

Answer 6

• Insertion: lateral surface of vocal process of arytenoid cartilage
• Origin: ipsilateral vocal ligament
• Innervation: inferior laryngeal n. (terminal part of recurrent laryngeal n. from CN X)
• Function: relaxes posterior vocal ligament while maintaining (or increasing) tension of anterior part