Mucin Function — MFDS Part 1 MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: C — Form a lubricating, protective film over the oral mucosa
Salivary mucins, particularly the gel-forming mucin MUC5B together with MUC7, contribute to the hydrated mucosal pellicle. This viscoelastic layer retains moisture, reduces friction and protects oral soft tissues from mechanical and environmental injury. Therefore, A is the single best answer. Mucins can bind or aggregate microorganisms and assist their clearance, but their principal action is not direct bacterial killing. Dietary starch is hydrolysed mainly by salivary alpha-amylase, while bicarbonate is the principal salivary buffer. Calcium-phosphate homeostasis and remineralisation depend on dissolved mineral ions and proteins such as statherin rather than representing the primary function of mucins.
Reference: Hannig C, Hannig M, Kensche A, Carpenter G. The mucosal pellicle—An underestimated factor in oral physiology. Archives of Oral Biology. 2017;80:144–152. https://pubmed.ncbi.nlm.nih.gov/28419912/