Ghada aldakheel
اشترك منذ 29 يونيو 2013
<textbook of immunology by SEEMI FARHAT BASIR/>قالب:IMMUNE SYSTEM--Ghada aldakheel (نقاش) 16:43، 29 يونيو 2013 (ت ع م)
- The word immunity,which means the state of protection from infectious diseases,
- is derived from the Latin term immunis meaning 'exempt'.
- There are two systems of immunity ,innate and adaptive.
INNATE IMMUNITY; Innate immunity comprises of four types of defensive barriers:anatomic, physiologic, phagocytic ,and inflammatory. The skin and the surface of mucous membranes are the anatomic barriers. The skin acts as a mechanical barrier that retards the entry of microbes.The continuous renewal of epithelial cells, lining the skin surface and acidic environment(pH 3-5) too retards growth of microbes.