immunoglobulins

Question 1

IgG (75% of total immunoglobulins)

Answer 1

• assumes major role in bloodborne and tissue infections
• activates the compliment system
• enhances phagocytosis
• crosses the placenta
• appears in serum and tissues (interstitial fluid)

Question 2

IgA (15% of total immunoglobulins)

Answer 2

*in body fluid (blood, saliva, tears, breast milk, and
pulmonary, gi, prostatic, vaginal secretions
*protects against respiratory, gi/gu infections
*prevents absorption of antigens from foods
*passes to neonate in breast milk for protection

Question 3

IgM (10% of total immunoglobulins)

Answer 3

*mostly in intravascular serum
*first immunoglobulin produced in response to bacterial
and viral infections
*activates the compliment system

Question 4

IgD (0.2% of total immunoglobulins)

Answer 4

*appears in small amount of serum
*possible influences B-lymphocyte differentiation, role
unclear

Question 5

IgE (0.004% of total immunoglobulins)

Answer 5

• appears in serum
• takes part in allergic and some hypersensitivity reactions
• combats parasite infections