Muscles of the Larynx Flashcards
Name the 5 major muscles of the larynx
- Cricothyroid
- Thyroarytenoid
- Posterior cricoarytenoid
- Lateral cricoarytenoid
- Transverse arytenoids
What is the origin of the cricothyroid muscle?
Anterolateral part of cricoid cartilage
What is the insertion of the cricothyroid muscle?
Inferior part of thyroid cartilage
What is the innervation of the cricothyroid muscle?
Vagus through external laryngeal nerve
What is the main action of the cricothyroid muscle?
Tenses vocal ligaments
What are the 2 origins of the thyroarytenoid muscle?
- Inner surface of thyroid cartilage
2. Cricothyroid ligament
What is the insertion of the thyroarytenoid muscle?
Anterolateral surface of arytenoid
What is the innervation of the thyroarytenoid muscle?
Recurrent laryngeal nerve
What is the main action of the thyroarytenoid muscle?
Relax vocal ligaments
What is the origin of the posterior cricoarytenoid muscle?
Posterior surface of cricoid cartilage
What is the insertion of the posterior cricoarytenoid muscle?
Muscular process of arytenoid cartilage
What is the innervation of the posterior cricoarytenoid muscle?
Recurrent laryngeal nerve
What is the main action of the posterior cricoarytenoid muscle?
Abduct the vocal ligaments
What is the origin of the lateral cricoarytenoid muscle?
Arch of cricoid cartilage
What is the insertion of the lateral cricoarytenoid muscle?
Muscular process of arytenoid cartilage
What is the innervation of the lateral cricoarytenoid muscle?
Recurrent laryngeal nerve
What is the main action of the lateral cricoarytenoid muscle?
Adduct vocal ligaments
What is the origin of the transverse arytenoids?
One arytenoid cartilage
What is the insertion of the transverse arytenoids?
Contralateral arytenoid cartilage
What is the innervation of the transverse arytenoids?
Recurrent laryngeal nerve
What is the main action of the transverse arytenoids?
Adduct posterior part of rima glottidis
Name 3 muscles responsible for narrowing the laryngeal inlet
- Oblique arytenoid
- Aryepiglottic muscle
- Thryroepiglottic muscle
Name the muscle responsible for increasing length and tension of vocal ligaments
Cricothyroid
Explain how the vocal ligaments are lengthened and tensed
Cricothyroid increases distance between angle of thyroid cartilage and vocal process of arytenoid cartilages
Name the muscle responsible for decreasing length and tension of vocal ligaments
Thyroarytenoid
Explain how the length and tension in vocal ligaments is decreased
Thyroarytenoid pulls arytenoid cartilage forward toward the thyroid cartilage
What occurs if the posterior cricoarytenoid is paralysed?
Asphyxia
What are the 2 divisions of the superior laryngeal nerve?
- External laryngeal nerve
2. Internal laryngeal nerve
Where does the external laryngeal nerve supply?
Cricothyroid muscle
Where does the sensory part of the internal laryngeal nerve supply?
Laryngeal cavity to the level of the vocal ligaments
Where does the sensory part of the recurrent laryngeal nerve supply?
Laryngeal cavity below the level of the vocal ligaments
Where does the motor part of the recurrent laryngeal nerve supply?
All intrinsic muscles of larynx except cricothyroid
What is the lymphatic drainage of the larynx above the level of the vocal ligaments?
Superior deep cervical lymph nodes
What is the lymphatic drainage of the larynx below the level of the vocal ligaments?
Inferior deep cervical lymph nodes
