Stress-Response
Background--Defense against pathogens
The body has two systems to defend against pathogens, or infectious agents:
specific defense system--immune system
- this system attacks substances detected as “foreign” by proliferating cells that either attack the invader directly or produce specific defensive proteins called antibodies that lead to the destruction of the pathogen
- B cells and T cells are lymphocytes that originate in bone marrow; B cells also mature in bone marrow--hence B designation; T cells migrate to, and mature within, the thymus--hence the T designation; the maturation process involves development of immunocompetence--specific cells in both groups can detect unique antigenic regions of bacteria and viruses--capacity for selective destruction of viruses and bacteria
- several types of T cells: helper T cell, cytotoxic T cell, suppressor T cell; one main type of B cell; however, there are a multitude of T and B cells that respond to different antigenic sequences of different pathogens