Antibody subclasses

Question 1

IgM

Answer 1

produced early in immune response. effective agglutinator, first produced in early embryonic life, effecticve against bacteria, 3rd most abundant.

Question 2

IgD

Answer 2

Present on nearly all lymphocytes, 4th most abundant serum Ab

Question 3

IgG

Answer 3

Most abundant serum Ab of internal body fluids especially extravascular, where it combats microorganisms and toxins, crosses placenta, binds to macrophages and neutrophils.

Question 4

IgA

Answer 4

Major Ab of seromucus secretions where it defends external body surfaces (Saliva, tears, colostrum of milk); binds to macrophages and neutrophils; 2nd most abundant; endocytosed and transported to apical suface for release into lumen (mucosal surfaces, digestive tract)

Question 5

IgE

Answer 5

Protect external body surfaces, recruits antimicrobial agents, elevated in parasitic infections, central to atopic allergic reactions, and anaphylaxis, bound to eosinophils and mast cells. 5th most abundant