Involves the ability to recognize, respond to, and remember a particular substance
Stimulants and Types of Adaptive Immunity
-Stimulants>
*Antigens: Large molecules
**Foreign: Not produced by body, introduced from outside
**Self-antigens: Produced by body
**Haptens: Small molecules and capable of combining
=Types
*Humoral or Antibody-mediated: B cells
*Cell-mediated:tcel
Origin and Development of Lymphocytes
B and T cells
--Originate in red bone marrow
--Move to lymphatic tissue from processing sites and continually circulate
---Clones are small groups of identical lymphocytes
Origin and Development of Lymphocytes II
Positive selection=
Ensures survival of lymphocytes that react against antigens
-Negative selection=
Eliminates lymphocytes that react against self-antigens
Origin and Development of Lymphocytes III
Primary lymphatic organs (red bone marrow, thymus)=
Where lymphocytes mature into functional cells
--Secondary lymphatic organs
=Where lymphocytes produce an immune response
Major Histocompatability Complex (MHC)
-Most lymphocyte activation involves glycoproteins of cell surfaces called MHC molecules
--Class I molecules display antigens on surface of nucleated cells, resulting in destruction of cells
--Class II molecules display antigens on surface of antigen-presenting cells, resulting in activation of immune cells
