Which property of saliva provides lubrication and viscoelasticity?

• A. Antibacterial
• B. Buffering
• C. Digestion
• D. Lubrication and viscoelasticity

Answer: (D)

Saliva’s lubrication and viscoelasticity come from the mucins, large glycoproteins that give saliva its gel-like, sticky quality. These mucins attract and hold water, forming a lubricating film that reduces friction between the tongue, cheeks, teeth, and the mucosal surfaces during chewing and speaking, and they help keep surfaces moist for easier swallowing. The viscoelastic network created by mucins also helps saliva cling to oral tissues, providing sustained moisture rather than a quick, dry wipe. Other saliva properties—antibacterial activity from enzymes and antibodies, buffering from bicarbonate and phosphate to neutralize acids, and digestive enzymes like amylase for carbohydrate breakdown—are separate functions, but they don’t primarily account for lubrication and the thick, elastic consistency of saliva.