Composition and Terminology
Nasal mucus is a complex biological fluid composed of water, ions, and various macromolecules, most notably mucin glycoproteins. 3 The term "mucus" is the proper scientific designation for this substance, while "snot" is merely colloquial. 2, 4
Key Components
- Mucin glycoproteins (mucins) are the primary macromolecular constituents responsible for the viscoelastic properties of mucus 2, 3
- At least eight mucin genes have been identified in human airways, with MUC5AC and MUC5B being the predominant gel-forming glycoproteins in airway mucus 2
- Additional components include water, ions, antimicrobial proteins, anti-protease factors, and antioxidants 3
Clinical Context
In medical literature and clinical practice, nasal mucus is often referred to as part of the airway surface liquid (ASL) when discussing its physiological role. 3 In disease states, particularly chronic rhinosinusitis, the term nasal secretions is frequently used interchangeably with nasal mucus in research contexts. 1
The mucins are heavily O-linked glycoproteins characterized by tandem repeating sequences of amino acids rich in serine and threonine, which serve as linkage sites for large carbohydrate structures. 4 This extensive glycosylation, rather than the polypeptide sequence itself, determines the biophysical properties of mucus. 5