Anatomy: Laryngeal Spaces (Compartments)
High-Yield Anatomical Landmarks for Board Review & PG Entrance Examinations
Understanding the spaces of the larynx is critical for staging laryngeal carcinoma and predicting the spread of infections. These spaces are defined by the elastic cone (conus elasticus) and the quadrangular membrane.
1. The Three Main Compartments
| Compartment | Boundaries/Features |
|---|---|
| Supraglottic Space | Extends from the laryngeal inlet to the superior surface of the vocal cords. Includes the vestibule. |
| Glottic Space | The area between the true vocal cords. It contains the glottis and anterior/posterior commissures. |
| Subglottic Space | Extends from 1 cm below the free edge of the vocal cords to the lower border of the cricoid cartilage. |
2. Critical Submucosal Spaces
- Paraglottic Space: A potential space lateral to the laryngeal ventricle. It is bounded:
- Medially: By the quadrangular membrane and conus elasticus.
- Laterally: By the thyroid cartilage.
- Significance: A critical pathway for transglottic spread of laryngeal cancer.
- Pre-epiglottic (Space of Boyer): A wedge-shaped space between the epiglottis, the thyrohyoid membrane, and the thyroid cartilage. It is filled with fat and is a common site for tumor extension from the epiglottis.
- Reinke’s Space: Located in the true vocal cords, between the epithelium and the vocal ligament.
- Significance: Site of Reinke’s Edema (often seen in smokers). Because it has sparse lymphatic drainage, early glottic tumors are often confined here for a longer duration.
3. High-Yield Clinical Correlation
| Feature | High-Yield Detail |
|---|---|
| Broyles’ Ligament | Anterior commissure tendon. Lacks a perichondrial barrier, allowing easy spread of the tumor to the thyroid cartilage. |
| Laryngeal Ventricle | The space between the false (ventricular) fold and the true vocal cord. |
| Lymphatic Drainage | The vocal cords have minimal lymphatic drainage, which explains the low rate of nodal metastasis in early glottic cancers. |