Introduction
Microscopic (histologic) description
- ➢ Mucosa - stratified columnar ciliated epithelium
- ➢ Lamina Propria - glands, tonsils
- ➢ Submucosa forms fibroelastic membrane
- Junction between epithelial types may be abrupt or separated by transitional area; patches of squamous epithelium in respiratory epithelium are common, particularly in smokers
- Dendritic melanocytes may be present in basal layer, particularly in blacks
- Epiglottis: stratified squamous epithelium similar to oral cavity with modified salivary glands that secrete thick mucous; laryngeal surface also has pits containing mucous glands
- Cartilage has full thickness fenestrae that communicate with pre-epiglottic space, which contains fat and areolar tissue
- False vocal cords and other supraglottic larynx: ciliated, columnar epithelium extending into ventricle of Morgagni with submucosal modified salivary gland epithelium
- Glottis: space between 2 vocal cords
- Hypopharynx: covered by nonkeratinizing stratified squamous epithelium; contains mucosal glands, scattered lymphoid aggregates and rich lymphatic plexus
- Reinke space: lamina propria of true vocal cord, between base of squamous epithelium and vocal ligament
- True vocal cords: stratified squamous epithelium with no / rare submucosal glands
- Subglottic larynx: epithelium resembles trachea / major bronchi - ciliated columnar epithelium with submucosal glands