Immune System

Question 1

IgM

Answer 1

First secreted immunoglobulin after B cell activation during primary immune response

Most B lymphocytes express membrane bound IgM

Most efficient at complement binding and activation

Question 2

IgD

Answer 2

Mainly co-expressed with IgM on the surface of mature, naive B lymphocytes where it functions as an antigen-specific receptor

Question 3

IgG

Answer 3

Most common immunoglobulin in serum and is produced in secondary antibody responses to most antigens

Move from blood to inflamed tissue when vascular permeability is increased

Can cross placenta

Question 4

IgA

Answer 4

Major immunoglobulin in bodily secretions (tears, saliva, mucus, etc…)

Produced by submucosal plasma cells

Question 5

IgE

Answer 5

Present in serum only at low concentrations because most is bound very tightly to Fc receptors on the surface of mast cells

Involved in inflammatory responses to extracellular parasites and allergic reactions