The Glottis and Subglottis: An Otolaryngologist's Perspective
Section snippets
Laryngeal subdivisions
The larynx is divided anatomically, embryologically, and clinically into three regions:
The supraglottic region, including the epiglottis, the arytenoid cartilages with the aryepiglottic folds, the vestibular folds, and the laryngeal ventricles.
The glottic region, including the vocal cords together with the anterior and posterior commissures.
The subglottic region, which extends from a plane that is approximately 1 cm below the free margin of the true vocal cords to the lower border of the
Histology
Most of the mucosa covering the larynx is composed of ciliated columnar epithelial tissue, except for the free edges of the aryepiglottic folds and the epiglottis, which are lined with stratified squamous mucosa. In addition, the true vocal cords are covered by stratified squamous epithelium. The transition from the stratified epithelium of the vocal cords to the respiratory epithelium is the histologic landmark of the lower border of the glottic region, which is located approximately 5 to 10
The glottis
The glottis is composed of the vocal folds, the vocal process of the arytenoids, and the anterior and posterior commissures. It is the laryngeal component that is most directly responsible for phonation. This is also the narrowest part of the airway. The anatomic term “rima glottidis” defines the space or aperture between the vocal folds and arytenoid cartilages, and its shape is determined by the position of these structures. This aperture in men is approximately 2 to 2.4 cm in length, and the
Visualization and imaging
Endoscopy with a flexible laryngoscope or bronchoscope is useful to visualize lesions or tumors; to identify the exact size, extent, and location of pathology (eg, a stenotic segment relative to the true vocal cords); or to obtain a biopsy under direct visualization. To provide a more detailed examination of the glottis and subglottis with magnification, rigid fiberoptic endoscopy may be performed using various scope angles (0°, 30°, 70°, and 90°).
In addition to endoscopy, radiographic imaging
Clinical correlation
The anatomy of the glottic and subglottic region is complex, and dysfunction may result in dysphonia, dysphagia, or airway obstruction with significant patient morbidity. Consideration of the intricate anatomy in this region is important for patient evaluation and management.
Summary
The complexity of the glottic and subglottic region in terms of anatomy and function make this region challenging in evaluation and treatment. A thorough understanding of the complex anatomy is necessary for the management of patients who have dysphonia, vocal fold paralysis, glottic or subglottic stenosis, or complications, which may present after prolonged intubation or surgical interventions in the upper airway and the thorax.
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Cited by (11)
Anatomy of the Larynx and Cervical Trachea
2022, Neuroimaging Clinics of North AmericaCitation Excerpt :The upper limit of the glottis can be identified as the inferior margins of the laryngeal ventricles, which are generally best seen on coronal imaging slices. The histologic landmark that demarcates the lower margin of the glottis is the transition zone from the stratified squamous epithelium covering the TC to the respiratory epithelium of the subglottic airway, which is usually located 5 to 10 mm below the free edge of the TC.31 However, this zone is not resolvable by imaging, so the inferior limit of the glottis is arbitrarily defined as the plane situated 1 cm inferior to the laryngeal ventricles for imaging purposes.2,19,29
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