Immune System in Action Specific immune response uses

Immune System in Action �Specific immune response uses two styles of action: 1. Humoral Immunity – depends on antibodies circulating blood and lymph 2. Cell-mediated Immunity – protects against own cells that become infected

Immune System in Action �Using cartoons… Gotcha! mmm… human cells! Macrophage Pathogen in body Pathogen eaten by macrophage

Immune System in Action Macrophage Antigen Pathogen torn apart Macrophage displays pieces of pathogen – called “antigens”

Immune System in Action Ok, let’s get ‘em! Helper T cell checks out antigen They look like this! Get em! Macrophage Helper T cell instructs B cells and T cells on what to attack Yes sir! B Cytotoxic T Yes Sir!

Cell-mediated immunity Cytotoxic T Your Time has come to die! Cytotoxic T Activated Cytotoxic T cells multiply and attack cells infected with the pathogen

Humoral Immunity plasma B plasma Activated B cells grow, divide, and develop into plasma cells plasma Plasma cells release antibodies that will only attack the pathogens Antibodies destroy pathogens

Immunity And don’t come back – we’ll remember what you look like! Memory T Memory B

Immunity �First exposure to pathogen – takes a few days for T & B cells to multiply �After infection, most T & B cells die except for memory cells �They quickly recognize and respond to the specific pathogen if they encounter it again �Response is so quick, you don’t notice any symptoms this is immunity

Immunity

Vaccines �Weak or inactive dose of pathogen �Stimulates adaptive immune response �Causes you to produce memory cell, leading to immunity �Active immunity – get from having the infection or vaccine �Passive immunity – receive antibodies from another source (mother to child); doesn’t last!