cavity of larynx
TRANSCRIPT
CAVITY OF THE LARYNX
ByJini Abraham
Laryngeal cavity is lined by the respiratory epithelium except the vocal cords and parts of epiglottis, which is lined by the stratified squamous epithelium.
The cavity starts at the laryngeal inlet where it communicates with the pharynx and ends at the lower border of the cricoid cartilage where it continues with the lumen of trachea.
The laryngeal inlet is bounded –Anteriorly – free margin of epiglottisLaterally – Aryepiglottic foldPosteriorly – Interarytenoid fold
Laryngeal interior is divided by two folds into three parts –
SupraglottisVestibuleVentricle
GlottisSubglottis
DIVISIONS
Folds dividing the cavity are – Vestibular folds –
False vocal cordsTwo in numberEach is fold of mucous membrane extending anteroposteriorly across laryngeal cavity
Contains vestibular ligament, few fibres of thyroarytenoideus muscle and mucous glands
Vocal folds – True vocal cordsTwo pearly-white shaped bands extending from the middle of thyroid angle to vocal processes of arytenoids
Each vocal cord consists of vocal ligament
Mainly constitutes –
EpiglottisAryepiglottic
foldsArytenoidsFalse cords
SUPRAGLOTTIS
Extends from laryngeal inlet to vestibular folds
Anterior wall formed by posterior surface of epiglottis
Sides by aryepiglottic foldsPosterior wall by mucous
membrane over anterior surface of arytenoids
VESTIBULE
Sinus of larynxDeep elliptical space between
vestibular and vocal folds
VENTRICLE
Diverticulum of mucous membrane which starts from the anterior part of ventricular cavity and extends upwards between vestibular folds and lamina of thyroid cartilage
Laryngocele – air containing sac present in the neck
Presence of mucous glands
SACCULE OF LARYNX
Rima glottidisElongated space between vocal cords
anteriorly and vocal processes and arytenoids posteriorly
24mm in men and 16mm in womenNarrowest part of laryngeal cavityAnterior two-thirds formed by
membranous cords and posterior one-third by vocal processes of arytenoids
GLOTTIS
Size and shape of glottis varies with movements of vocal cords
Infraglottic larynxExtends from vocal cords to lower
border of cricoid cartilage
SUBGLOTTIS
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