Introduction to lmmunology

Introduction to Immunology
Dr.Baha.Hamdi .Hakiem .AI-amiedie
Just as resistance to disease can be natural (inborn) or acquired,the mechanisms mediating it can be correspondingly divided into natural
and adaptive each composed of both cellular and humoral (i.e. free in serum or body fluids;) elements.Adaptive mechanisms, more recently evolved, perform many of their functions
while most cells can secrete interferon,
which acts against viruses but not other types of organism. the term non-specific , though often used as a synonym for
thus“natural”is not completely accurate Adaptive immunity is based on the special properties of lymphocytes (T and B,lymphocytes), which can respond selectively to thousands of different non-self materials, or antigens , leading to Specific memory and a permanently altered pattern of response-an adaptation to the animal s own surroundings. Adaptive mechanisms can function on their own against certain antigens
The mechanisms involved in natural immunity are largely the same as those responsible for non-specifically reacting to tissue damage, with The production of inflammation ,However, some cells (e.g. macrophages) and some
humoral factors (complement, lysozyme) do also have alimited ability to recognize and dispose of bacteria, while most cells can secrete