08-04-2006, 08:52 PM
Degranulation of mast cells and basophils occurs when allergen binds
to two adjacent IgE antibodies on the membrane of the cell 2. Interleukin
4 released by CD4 helper T cells causes activated B cells to switch from
making IgM to IgE 3. Processed allergen is associated with a class II
molecule on an antigen presenting cell and recognized by CD4+ TH2 cells
4. Prostaglandins and leukotrienes are released 5. The allergen is
phagocytized and processed by a macrophage or a dendritic cell
Based on the numbered list above, which of the following is the
correct sequence of events in the Type I hypersensitivity reaction?
A. 1,2,3,5,4
B. 1,4,3,5,2
C. 1,5,2,3,4
D. 5,3,1,4,2
E. 5,3,2,1,4
to two adjacent IgE antibodies on the membrane of the cell 2. Interleukin
4 released by CD4 helper T cells causes activated B cells to switch from
making IgM to IgE 3. Processed allergen is associated with a class II
molecule on an antigen presenting cell and recognized by CD4+ TH2 cells
4. Prostaglandins and leukotrienes are released 5. The allergen is
phagocytized and processed by a macrophage or a dendritic cell
Based on the numbered list above, which of the following is the
correct sequence of events in the Type I hypersensitivity reaction?
A. 1,2,3,5,4
B. 1,4,3,5,2
C. 1,5,2,3,4
D. 5,3,1,4,2
E. 5,3,2,1,4