PP. 961-966
lymphatic systemspleen lymphocytes 1. B-cells: wbc that
mature in bone marrow 2. T-cells: wbc that
mature in thymus
There are many different lymphocytes (wbc)
Each have receptors for different antigens (markers) Antigen: Identifies cell as foreign
2-part attack Cell-mediated: Killer T-Cell production Humoral: B-Cell production
Starts with an initial response
Initialresponse
HumoralB-Cell
production
Cell-mediatedT-Cell
production
1. macrophage engulfs pathogen and puts antigens on its surface2. Helper T-cell binds to antigen
3. Macrophage releases a chemical (INK-1) which causes the Helper T-cell to release INK-2
Initialresponse
HumoralB-Cell
production
Cell-mediatedT-Cell
production
INK-2INK-2
INK 2 stimulates the production of more Helper T Cells and Cytotoxic T Cells
Cytotoxic T Cell (killer T cell): kills infected body cells.
Initialresponse
HumoralB-Cell
production
Cell-mediatedT-Cell
production
INK-2 causes complimentary B-cells to divide
Most B-cells change to plasma cells
Plasma cells produce antibodies Y-shaped protein that deactivates
pathogen and clumps them making it easier for macrophages to engulf and destroy them.
Some B-cells become memory cells and store information about pathogen Body’s long term defense system
When exposed to pathogen a 2nd time, memory cells immediately recognize and destroy it before it causes illness.
primary: 1st time body encounters pathogens
secondary: 2nd time body encounters pathogen with memory cells (leftover B-cells and T-cells)
Immunity: ability to resist an infectious disease
Vaccination: introduction of antigens into body to cause immunity
Vaccine: solution of dead or weakened pathogens that contains pathogens Antigens produce a primary immune
response Memory cells created provide quick
secondary immune response if antigen enters body again.
http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter22/animation__the_immune_response.html
Some Diseases that have been controlled through vaccines: polio, measles, mumps, tetanus, and small pox