Human Defense Flashcards
What is meant by the term immunity?
Immunity is the ability to resist infection
Distinguish between an antigen and an antibody
Antigen: A substance on surface of virus or bacteria which causes antibody production
Antibody : produced in response to an antigen. Defence protein produced by lymphocytes
Outline briefly the role of B lymphocytes in the human immune system
Each B cell recognises only one antigen and produces only one antibody
B cell divides to form lots of plasma cells which produce antibodies in response to specific antigens
Antibodies attached to the antigen
Memory B cells are produced after an infection has been dealt with
Memory B-cell responds to smaller amounts of antigens than B cells so if it is the second infection antibodies are produced more quickly
Distinguish between active and passive immunity
Active immunity: when an organism produces their own antibodies against an infection. Body produces antibodies
Passive immunity: when individuals receive antibodies that have been produced by another organism. Antibodies introduced to the body
