Immunity Mechanisms

T cells. Effective against cells: our infected cells (bacterial or viral), fungi, parasites, cancer cells, foreign

activates by recognizing antigen fragments on the surface of a macrophage. It activates a B cell to produce antibodies

activates by recognizing antigens on cancer cells or virally infected body cells. It reproduces and kills abnormal cells.

remain in the body after exposure to an antigen and recognize antigen in later infections.

B cells. Effective against antigens NOT inside cells (bacterial, viral or other).  Activated by T cells.

secrete antibodies (immunoglobulins)

attack an antigen the 2nd time it enters the body.  More rapid & forceful than 1st exposure.