Question

1) Figure 16.19 describes primary and secondary responses to antigen, indicate where a vaccination might be most effective, and also indicate where natural infection would play a role.

2) Describe the major histocompatibility complex, and explain how it participates in immune reactions.

3) Describe three circumstances that might cause antibodies to develop against self-tissues.

4) Why would it be necessary for the T cells to bind both antigen and self (MHC) receptors?

5) Describe the role of the following in immune system:

a. Dendritic cells

b. Macrophages

c. Neutrophils

d. Mast cells

e. Eosinophils

f. Natural Killer Cells

Answer 1

Answer= 1.

Primary immune response = The primary immune response occurs when an antigen comes in contact to the immune system for the first time.During this time the immune system has learn to recognize antigen and how to make antibody antibody against it and eventually produce memory lyphocytes.

- Responding cell is naive B cell and T cell.

- Lag phase is often longer about 4- 7 days,sometimes long as weeks or months.

- level of antibody reaches peak in 7-10 days.

- first antibody produce is mainly IgM .although small amount of IgGare also produced.

- antibody level declines rapidly.

Secondary immune response= It occurs when the second time the person is exposed to the same antigen.At this point immunological memory has been established and immune system can start making antibodies immediately.

- Responding cell is memory cell.

- lag phase is shorter about 1-4 days due to presence of memory cell.

- level of antibody reaches peak in 3 to 5 days.

-Mainly IgG antibody is produced.Although sometimes small amount of IgM are produced.Other immunoglogilin s-- -- Such as IgA and in the case of allergy IgE are produced.

a vaccination might be most effective in primary immune response and also natural infection would play a role in secondary immune response.

occurs mainly in bone marrow,followed by the spleen and lymph nodes.