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first line of defense for body
Physical and chemical barriers:
- skin
- mucous, tears, saliva, sweat
- respiratory tract: mucous, cilia, coughing
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second line of defense (internal)
- white blood cells
- -Pathocytes
- -Lymphocytes: major role in pathogen response
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T cells
orchestrate and directly participate in defenses
- Helper T: signal killer Ts to multiply and to do their job: produce cytokines and chemical messengers
- Suppressor T: signal that pathogen has been dealt with. help to return to homeostasis
- Killer T: direct contact with infected cells - destroy them with cytotoxic chemicals
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