Chapter #22: Immunity Flashcards
Immunity
Ability to resist and defend against infectious organisms and other damaging substances
Resistance
Ability of body to maintain immunity
Immune response
Body’s reaction to infectious agents and other abnormal substances
Two types of immunity
- Innate (nonspecific) immunity
- Adaptove (specific) immunity
Innate (nonspecific) immunity
-Always works the same way
-Against any type of invading agent
Adaptive (specific) immunity
-Protects against specific pathogens
-Depends on activities of lymphocytes
-Develops after exposure to environmental hazards
Lymphocytes
B cells, T cells, and NK cells
Lymphocyte distribution
-Tissues maintain different T cell and B cell populations
-Lymphocytes wander through tissues
–Enter blood vessels or lymphatics for transport
–Can survive many years
Lymphocyte production
-Bone marrow
-Thymus
-Peripheral lymphoid tissues
Hemocytoblasts in bone marrow
Divide into two types of lymphoid stem cells
Lymphoid Stem Cells
-Group 1
–Remain in bone marrow and develop
–Produce B cells and NK cells
-Group 2
–Migrate to thymus
–T cells differentiate with exposure to hormones
Immune Surveillance
-NK cells attack foreign cells, body cells infected by viruses, and cancer cells
-They secrete chemicals that lyse the plasma membrane of the abnormal cells
Antibody-mediated Immunity
-When stimulated, B cells can differentiate into plasma cells, which produce and secrete antibodies
-These antibodies attach to pathogens
-This starts a chain reaction that leads
to the destruction of the pathogen
