Introduction
Immunity
or
resistance is the ability to ward off damage or disease through our
defenses
The two general types of immunity
ü Innate
(nonspecific) immunity refers to defenses that
are present at birth. Among the
components of innate immunity are the first line of defense (the physical and
chemical barriers of the skin and mucous membranes) and the second line of
defense (antimicrobial substances, natural killer cells, phagocytes,
inflammation, and fever).
ü Adaptive
(specific) immunity refers to defenses that
involve specific recognition of a microbe once it has breached the innate
immunity defenses. Adaptive immunity is based on a specific response to a
specific microbe; that is, it adapts or adjusts to handle a specific microbe.
Adaptive immunity involves lymphocytes (a type of white blood cell) called T
lymphocytes (T cells) and B lymphocytes (B cells).
