TY - CHAP M1 - Book, Section TI - Immunology Review A1 - LU, Kurt Q. A1 - Novoa, Roberto A. A2 - Ali, Asra Y1 - 2015 N1 - T2 - McGraw-Hill Education Specialty Board Review Dermatology: A Pictorial Review, 3e AB - The human body can respond to antigen via innate and/or adaptive immunity (Fig. 27-1)Innate immunity (nonspecific, nonclonal, no anamnestic characteristics)Characteristics– Immediate first-line defense against pathogens composed of 3 major componentsNonspecific physical and chemical barriersRecruitment and activation of leukocytesRelease and/or activation of extracellular humoral mediators (i.e., cytokines, complement)– Exists prior to exposure to a given microbe or antigen (requires no previous exposure) and is rapidly available on pathogen encounter (minutes)Key components– Physical and chemical barriers to pathogen invasionSkin, mucous membranes, cilia, and secretions (mucous and sweat) cover body surfaces and prevent microorganisms and other potentially injurious agents from entering the tissues beneathMucus traps, dissolves, and sweeps away foreign substancesSweat contains lactic acid and other substances that maintain the surface of the epidermis at an acidic pH, thereby decreasing colonization by bacteria and other organismsChemical barrier antimicrobial substances include enzymes that can directly injure or kill microbial pathogens SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - dermatology.mhmedical.com/content.aspx?aid=1176112478 ER -