Larynx

Overview and topographic anatomy

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Larynx— connection between the pharynx and the trachea
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Prevents foreign bodies from entering the airways
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Designed for the production of sound (phonation)
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Is mobile during deglutition
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Located in the midline opposite the 3rd to the 6th cervical vertebrae (C3 to C6)
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Shorter in women and children
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Prepubescent larynx is similar in size in females and males
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After the onset of puberty, the larynx in males enlarges significantly
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Formed by 9 cartilages: 3 paired and 3 unpaired
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Vallecula is a depression in the mucosa between the pharyngeal portion of the tongue and the anterior border of the epiglottis
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Laryngeal epithelium is primarily pseudostratified columnar with cilia, except:
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  Anterior surface along the epiglottis—stratified squamous nonkeratinized
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  True vocal cord—stratified squamous nonkeratinized
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Regions of the larynx:
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  Vestibule (supraglottic)—from the laryngeal inlet to the vestibular folds
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  Ventricle—from the vestibular fold to the vocal fold
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  Infraglottic (subglottic)—from vocal folds to the inferior border of the cricoid cartilage

Cartilage	Cartilage Type	Paired	Comments
Thyroid	Hyaline	No	Largest of the laryngeal cartilages Connects to the hyoid bone via the thyrohyoid membrane, which allows the internal laryngeal n. and superior laryngeal vessels to pass through to enter the larynx Lies between C4 and C6
Cricoid	Hyaline	No	Only complete ring of cartilage in the respiratory system Signet in shape Both intrinsic and extrinsic laryngeal muscles attach to the cricoid Lies at C6
Arytenoid	Hyaline (majority of arytenoid cartilage) Elastic (only the apex and small portion of vocal process)	Yes	Forms framework of the true vocal cord
Epiglottis	Elastic	No	Helps prevent foreign bodies from entering the larynx
Corniculate (minor)		Yes	Minor cartilages that lie in the aryepiglottic fold
Cuneiform (minor)		Yes	Minor cartilages that lie in the aryepiglottic fold

Anatomic Feature	Comments
2 lateral laminae	2 plates that meet at an acute angle in the anterior midline
Laryngeal prominence	Also known as the Adam’s apple Formed by the fusion of the 2 lateral lamina The fusion of the 2 lateral lamina forms an angle that is more acute in males (90 degrees) than females (120 degrees) Larger in males than in females
Thyroid notch	Superior portion of the laryngeal prominence, which forms a V shape
Superior tubercle	Superior border of the oblique line
Oblique line	Attachment for sternothyroid, thyrohyoid, and inferior constrictor mm. (extrinsic muscles of the larynx)
Inferior tubercle	Inferior border of the oblique line
Superior horn	Provides lateralmost attachment for the thyrohyoid membrane
Inferior horn	Articulates with the cricoid to form the cricothyroid joint

Anatomic Feature	Comments
Arch (anteriorly)	6 mm in height Narrow Cricothyroid m. attaches to the arch Inferior portion of the inferior constrictor m. (cricopharyngeus) attaches to the arch posterior to the cricothyroid m.
Lamina (posteriorly)	2–3 cm in height Posterior cricoarytenoid m. attaches to the lamina
Superior border (on the lamina)	Articulates with the arytenoid cartilage to form the cricoarytenoid joint
Inferior border (on the lamina)	Articulates with the inferior cornu of the thyroid cartilage to form the cricothyroid joint

Anatomic Feature	Comments
Divided into:	Are paired Each arytenoid cartilage has: ▪ 3 surfaces (anterolateral, posterior, medial) ▪ Apex ▪ Base (with 2 processes)
Apex	Apex is the superior extension of the arytenoid cartilage Corniculate cartilage articulates with the apex Apex is composed of elastic cartilage
Base	Base is the larger broad surface that articulates with the cricoid cartilage ▪ Has a muscular process (lateral process) that extends laterally and provides for muscular attachment ▪ Has a vocal process (anterior process) that extends anteriorly and gives rise to the true vocal cord Composed of hyaline cartilage (except a small portion of the vocal process) Base articulates with cricoid to form the cricoarytenoid joint Arytenoid cartilage can dislocate between the base and cricoid cartilages as a complication from instrumentation of the airway

Feb 15, 2025 | Posted by drzezo in General Dentistry | Comments Off