True or False: Interferon reactions are part of the third line of defense. 

Define herd immunity?  Explain specifically how herd immunity is achieved. Which groups are protected and why it is important.

_________________ act(s) as a filter to remove pathogens from lymphatic circulation.

The ___________ theory of disease stated that diseases were transmitted by clouds of bad air. 

_________________ hypersensitivities occur when IgE antibodies bind to the surface of mast cells & basophils and re-exposure to the antigen triggers a release of inflammatory mediators.

Histoplasmosis is habitually present in Indiana and a certain number of cases is expected each year. This is an example of a(n) ________ disease. 

Titer is defined as ___________ in a patient’s blood.

The first line of defense includes ___________. 

True or False: Antigens are recognized as “non-self” by immune cells. 

True or False: The two major groups of leukocytes are granulocytes and agranulocytes.