NURSING 3PA2 Lecture Notes - Lecture 4: Adaptive Immune System, Cytotoxic T Cell, Innate Immune System
22 Nov 2016
School
Department
Course
Professor
Document Summary
Re(cid:272)all that the (cid:271)od(cid:455)"s first line of defence is provided by the intrinsic barriers of the skin and mucus membranes, which may be mechanical, chemical, or microbiological in nature. Mechanical: expulsive forces (coughing, sneezing, defecation and urination) help to rid the body of pathogens before they can attach to and breach the mucus membranes. Ciliary beating helps to sweep pathogens from the upper and lower airways. Tight junctions in epithelium prevent pathogens from slipping between cells to enter underlying host tissue. Chemical: low ph barriers (stomach, vaginal fluids and sebaceous fatty acids) prevent pathogenic bacterial colonization. Proteolytic enzymes (lysozymes, pepsin in gut) breakdown pathogenic components. Microbiological: commensal flora compete with pathogens for resources (space and nutrients). The innate immune system consists of many components including phagocytes, natural killer cells, the inflammatory response, antimicrobial proteins including interferons and complement, and fever. Phagocytes: mai(cid:374)l(cid:455) (cid:272)o(cid:374)sist of tissue (cid:396)eside(cid:374)t a(cid:374)d (cid:862)(cid:449)a(cid:374)de(cid:396)i(cid:374)g(cid:863) (cid:373)a(cid:272)(cid:396)ophages.
