Does the larynx produce mucus?

Laryngeal Mucus Production

Yes, the larynx does produce mucus as part of its normal physiological function. The larynx is lined with mucous membrane that secretes mucus to protect and lubricate the vocal folds and surrounding structures 1.

Anatomy and Physiology of Laryngeal Mucus Production

The larynx consists of a framework of cartilages and fibroelastic membranes covered by muscles and lined with mucous membrane 1. This mucous membrane contains:

• Goblet cells that secrete mucus
• Ciliated epithelial cells that help move the mucus
• Submucosal glands that contribute to mucus production

The mucus produced by the larynx serves several important functions:

1. Protection: Creates a protective barrier against inhaled particles, pathogens, and irritants
2. Lubrication: Facilitates smooth movement of the vocal folds during phonation
3. Hydration: Maintains proper moisture levels of the vocal folds

Clinical Significance of Laryngeal Mucus

Normal Function

In healthy individuals, laryngeal mucus forms part of the mucociliary clearance system. The ciliated epithelium works with the mucus layer to trap and remove foreign particles through coordinated metachronal waves 2. This mucus is typically cleared through the action of cilia toward the hypopharynx, where it is swallowed and rarely noticed 3.

Pathological Changes

Several conditions can affect laryngeal mucus production:

1. Smoking: Causes dysfunction of normal metachronal waves that drive mucus clearance, leading to:

   • Disruption and defoliation of ciliated epithelium
   • Increased goblet cell numbers and mucous gland hyperplasia
   • Squamous metaplasia of respiratory epithelium 2

2. Laryngopharyngeal Reflux (LPR): Can cause excess mucus production in the throat, along with symptoms like throat clearing, hoarseness, and cough 4

3. Sensory Laryngeal Neuropathy (SLN): Presents with increased mucus production, among other symptoms like globus pharyngeus and chronic cough 5

Characteristics of Laryngeal Mucus

Research has shown that human laryngeal mucus from the vocal folds has variable rheological properties:

• Some samples show solid-like characteristics (more viscous)
• Others demonstrate liquid-like properties (more fluid)
• Smoking appears to affect mucus consistency, with current smokers having mucus of predominantly liquid-like character 6

Mucus Fluidification

An interesting aspect of laryngeal mucus management is its fluidification. Research suggests that saliva from the oral and pharyngeal cavities enters the larynx and is adsorbed on its mucosa, acting as a natural layer that helps fluidize the mucus of the laryngeal vestibule 7. This mechanism appears to be important for maintaining optimal mucus consistency for proper vocal fold function.

Clinical Implications

Understanding laryngeal mucus production is important for:

1. Voice disorders: Abnormal mucus consistency can affect voice quality and contribute to dysphonia
2. Airway protection: Proper mucus function is essential for protecting the lower airways from aspiration
3. Treatment approaches: Conditions involving abnormal mucus production (excessive or insufficient) may require specific interventions

When evaluating patients with voice complaints or laryngeal symptoms, assessment of mucus production and characteristics should be part of the examination, as alterations can indicate underlying pathology.