AH 3121 Chapter Notes - Chapter 1: Titer, Lymphocyte, Homeostasis
Document Summary
The immune system is a collection of cells, tissues, and molecules that provide immunity, which is resistance to infectious disease, by detecting and eliminating infectious microorganisms through the immune response. Defends against infections: deficient immunity results in increased susceptibility to infections; exemplified by aids, vaccination boosts immune defenses and protects against infections. The immune system recognizes and responds to tissue grafts and newly introduced proteins: immune responses are barriers to transplantation and gene therapy. Defense against tumors: potential for immunotherapy of cancer, immune surveillance scanning for foreign antigens/cells. Protects against four classes of pathogens: bacteria, viruses, fungi, parasites. Specificity ensures that distinct antigens elicit specific responses; must protect against unknown antigen; had antibodies for unknown antigens that may never be activated. Constantly produce t & b cells ready to fight antigen. Diversity enables immune system to respond to a large variety of antigens; same purpose as specificity. Memory leads to enhanced responses to repeated exposures to the same antigens.
