1. SPECIFIC IMMUNE SYSTEM

2. Specific body defenses: 1.It is antigen specific 2.It has “memory”

3. 2 divisions/types of responses Antibody-mediated Cell-mediated

4. How it functions 1.Antibody-mediated: B cells (a lymphocyte) produce proteins called antibodies that inactivate antigens

5. The details 1.Immature B cells fully mature when an antigen binds to its surface receptors. 2.B cell multiplies rapidly to form an army of cloned cells 3.Most cloned cells: plasma cells - produce antibodies (live for 4-5 days, then die.) 4.Other B cells: memory cells (faster for secondary response)

6. Actions of antibodies: Prevents virus from attaching to cells Impair bacteria movement  spread Attract phagocytes Antibiotics: temporary antibodies

7. Clones itself when attaches to antigen Some clones become plasma cells Some clones become memory cells Produce antibodies LIFE OF A B CELL

8. PLASMA CELLS MEMORY CELLS Descend from B cells Involved in specific response Produce antibodies Secondary response Live years Live days 1 st exposure Quicker response

9. Cell-mediated immune response 1.T cells clone themselves when they encounter an antigen 2.Cloned into different classes of T cells in lymphatic organs/tissue…

10. a. Cytotoxic T cells (killer T cells) Injects chemical to destroy host cell Targets body cells infected by microbes, some cancer cells, and cells of a tissue transplant.

11. b. Helper T cells Produce protein hormone – cytokines- to stimulate killer T cells, B cells and natural killer cells to grow and divide targeted/destroyed by HIV

12. c. Memory T cells survive for years; enables body to respond quickly and efficiently to the same antigen.

13. vaccines Weakened microbe Activates immune cells – triggers production of memory cells Encounter living microbe: secondary response = faster and never actually get symptoms