Micro & Immunology · single question
What is the MAJOR immunoglobulin found in SALIVA?
Show answer and explanation
Correct answer: A. Secretory IgA (sIgA)
Secretory IgA (sIgA) is the predominant immunoglobulin in saliva and mucosal secretions. Produced by plasma cells in salivary gland tissue, it is secreted as a dimer with a secretory component (J chain) that protects it from proteolytic degradation. sIgA prevents microbial adherence to mucosal surfaces (immune exclusion) and neutralizes viruses — it is the first line of mucosal immune defense.
- A. CORRECT. Secretory IgA (sIgA) is the predominant immunoglobulin in saliva — key mucosal immune defense.
- B. Incorrect. IgG is most abundant in SERUM — not the primary salivary immunoglobulin.
- C. Incorrect. IgM is the first antibody in primary immune responses — found mainly in blood.
- D. Incorrect. IgE is involved in allergic reactions — not found in significant quantities in saliva.
Practice Micro & Immunology questions Micro & Immunology study notes