LARYNX Flashcards
Enumerate the intrinsic muscles of the larynx.
- Cricothyroid, 2. Posterior cricoarytenoid, 3. Lateral cricoarytenoid, 4. Thyroarytenoid, 5. Transverse arytenoid, 6. Oblique arytenoid, 7. Vocalis
Cricoid Thyroid - Origin?
Anterolateral aspect of the cricoid cartilage.
Cricoid Thyroid - Insertion?
Lower border and inferior horn of the thyroid cartilage.
Cricoid Thyroid - Nerve Supply?
External branch of the superior laryngeal nerve (branch of vagus).
Cricoid Thyroid - Action?
Tenses and elongates the vocal cords by tilting the thyroid cartilage forward.
Posterior Cricoarytenoid - Origin?
Posterior surface of the cricoid cartilage.
Posterior Cricoarytenoid - Insertion?
Muscular process of the arytenoid cartilage.
Posterior Cricoarytenoid - Nerve Supply?
Recurrent laryngeal nerve (branch of vagus).
Posterior Cricoarytenoid - Action?
Only muscle that abducts the vocal cords, widening the glottis.
Short Note: Laryngeal Inlet?
Opening of the larynx into the pharynx; bordered by the epiglottis anteriorly, aryepiglottic folds laterally, and arytenoid cartilages posteriorly.
Short Note: Piriform Fossa?
Depression on either side of the laryngeal inlet, within the laryngopharynx; a common site for food lodgment.
Short Note: Vocal Cords?
Paired structures composed of mucosa and vocal ligament; responsible for phonation. True vocal cords are white and avascular.
Short Note: Cricothyroid Muscle?
Intrinsic laryngeal muscle that tenses the vocal cords by tilting the thyroid cartilage; supplied by the external branch of the superior laryngeal nerve.
Enumerate the cartilages of the larynx.
- Unpaired: Thyroid, Cricoid, Epiglottis; 2. Paired: Arytenoid, Corniculate, Cuneiform.
Enumerate the subdivisions of the laryngeal cavity (coronal section).
- Vestibule (above vestibular folds), 2. Ventricle (between vestibular and vocal folds), 3. Infraglottic cavity (below vocal folds).
Anatomical basis of Vocal Nodules/Singer’s Nodules?
Caused by excessive strain on vocal cords (e.g., in singers); results in thickening and fibrosis of the mucosa at the junction of the anterior and middle thirds of the vocal cords.
Anatomical basis of Laryngocele?
Dilation of the laryngeal ventricle, usually due to increased pressure in wind instrumentalists or glass blowers.
Anatomical basis of Cadaveric Position of Vocal Cords?
Due to bilateral recurrent laryngeal nerve injury, causing both vocal cords to remain midway between abduction and adduction.
Draw and label: Laryngoscopic view of the laryngeal cavity?
(Diagram required: Laryngoscopic view showing epiglottis, vestibular folds, vocal cords, arytenoid cartilages, interarytenoid notch, and glottis.)
Draw and label: Coronal section of the laryngeal cavity?
(Diagram required: Coronal section showing vestibule, ventricle, infraglottic cavity, cartilages, and folds.)
What is the arterial supply of the larynx above the vocal fold?
Superior laryngeal artery, a branch of the superior thyroid artery.
What is the arterial supply of the larynx below the vocal fold?
Inferior laryngeal artery, a branch of the inferior thyroid artery.
What is the venous drainage of the larynx?
Veins accompany the arteries: 1. Superior laryngeal vein → superior thyroid vein. 2. Inferior laryngeal vein → inferior thyroid vein.
How does lymphatic drainage of the larynx occur above the vocal cords?
Lymphatics pierce the thyrohyoid membrane, follow the superior thyroid vessels, and drain into upper deep cervical lymph nodes (anterosuperior group).
How does lymphatic drainage of the larynx occur below the vocal cords?
Lymphatics pierce the cricothyroid membrane, go to the prelaryngeal and pretracheal nodes, then drain into lower deep cervical lymph nodes (posteroinferior group).
What is the Rima Glottidis?
The narrowest anteroposterior cleft of the laryngeal cavity.
What is the anteroposterior diameter of the glottis in males and females?
24 mm in adult males, 16 mm in adult females.
What are the boundaries of the Rima Glottidis?
- Anterior: Angle of thyroid cartilage. 2. Posterior: Interarytenoid folds of the mucous membrane. 3. Lateral: Vocal fold (anterior 3/5) and vocal process of arytenoid cartilage (posterior 2/5).
What are the subdivisions of the Rima Glottidis?
- Intermembranous part (anterior 3/5, between vocal cords). 2. Intercartilaginous part (posterior 1/5, between vocal processes of arytenoid cartilage).
How does the shape of the Rima Glottidis change?
It varies with movements of the vocal cords, affecting phonation and breathing.
