Components of Immune System

Surface Barriers

Physical

·       Waxy cuticle of plants

·       Exoskeleton of arthropods

·       Intact layer of skin

 

Chemical

·       Perspiration has high salt content and contains lysozyme

·       Tears contain lysozyme

·       Low pH of gastric juices kill most bacteria

 

Innate immune system

1.   Response is non-specific

2.   Inflammation – redness and swelling are indicative of increased blood flow to deliver defenses to affected area

3.   Exposure leads to immediate maximal response

4.   Cell-mediated components

·       Neutrophils

·       Monocytes differentiate into macrophages

 

5.Humoral components

·       Complement – a biochemical cascade of over 20 proteins which collectively work to lyse bacteria.

 

6.   No immunological memory

7.   Found in nearly all forms of life

 

Adaptive immune system

1.   Pathogen and antigen specific response – B cells will produce antibody molecules

 

http://www.bio.davidson.edu/people/sosarafova/Assets/Bio307/jehodge/Assets/better%20antibody.gif

 

1.   Lag time between exposure and maximal response

AntigenResponses.jpg

 

2.   Cell-mediated components

http://upload.wikimedia.org/wikipedia/commons/thumb/e/ec/Lymphocyte_activation_simple.png/300px-Lymphocyte_activation_simple.png

 

3.   Humoral components

http://www.mcld.co.uk/hiv/images/cytokinesAndBCellActivation.gif

 

4.   Exposure leads to (long-term) immunological memory

5.   Found only in jawed vertebrates