Which set correctly lists the five layers in the 5-Layer Model of the vocal folds?

• A. Epithelium, superficial lamina propria, intermediate lamina propria, deep lamina propria, thyrovocalis/thyroarytenoid muscle
• B. Mucosa, ligament, muscle
• C. Cover, transition, body
• D. Epithelium, deep lamina propria, superficial lamina propria, middle lamina propria, vocal muscle

Answer: (A)

The five-layer model describes the vocal folds as a surface-to-deep tissue stack with distinct mechanical properties that shape vibration. From outside in, the layers are the epithelium, the superficial lamina propria (a loose, gelatinous layer that allows the mucosal wave to travel), the intermediate lamina propria, the deep lamina propria (together forming the vocal ligament with increasing stiffness), and the thyroarytenoid muscle (the vocalis) at the core. This arrangement lets a flexible cover glide over a stiffer ligament and a muscular body, producing the characteristic mucosal wave essential for phonation. Other options either compress these into broader categories, lump them into only three layers, or list a nonstandard term like “middle lamina propria,” and therefore don’t reflect the standard five-layer structure.